Aces High Bulletin Board
General Forums => Hardware and Software => Topic started by: Martlet on October 17, 2003, 03:47:47 PM
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I'm looking to upgrade, and have several that my dealer recommended.
For video cards, I'm looking at the FX 5200 128 (http://macenaonlinecomputer.e-partner.us/e-partner/details.asp?item=APFX5200128) or the FX 5200 256 (http://macenaonlinecomputer.e-partner.us/e-partner/details.asp?item=APFX5200256) . There's 40 bucks difference, but is the quality difference worth the cost?
For CPU, I'm thinking about the Athlon Barton 2500+ (http://macenaonlinecomputer.e-partner.us/e-partner/details.asp?item=AMD%2DBARTON%2D2500) and I currently have the Athlon XP 2000+ (http://macenaonlinecomputer.e-partner.us/e-partner/details.asp?item=XP2000) . Again, would I notice the difference for the cost? Would it be better to go up to the Athlon 2800+ (http://macenaonlinecomputer.e-partner.us/e-partner/details.asp?item=AMD%2DBARTON%2D2800) for an extra 100 bucks, or am I fine with what I have? My motherboard will handle either.
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mart... i just bought the Ti 4600.
everyone been saying bad stuff about the FX series... ill let you know how this ti works.
though i never found out why there was a ti4600 from chaintech that was over $60 more than the ti4600 by MSI that i bought.
i paid $179 US BTW on newegg for the MSI.
it was shipped out today to me ill let you know how it works.
(im running an XP1900+ so similar system to yours though 768mb DDRRam)
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Any particular reason you're not looking at ATI cards? That's the way I'd go if I were in the market for a new video card right now.
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I have the g force ti 4600 and my next card will be ATI.
As far as motherboard goes I have and love the Abit IC7MAX3
also I would say go INTEL you can get a p4 2.4 800FSB for about
165.00 at http://www.newegg.com
good luck.
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Originally posted by Tarmac
Any particular reason you're not looking at ATI cards? That's the way I'd go if I were in the market for a new video card right now.
I know absolutely nothing about this stuff. That's just what they suggested. I'll take any suggestions others may have.
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Ahh ok. I haven't been doing research since I bought my last card (GF4 Ti4200), but from the occasional article I read, ATI is the way to go now. The GF4 series was soundly whomped by the Radeon 9000 series. Nvidia came back and answered with its Geforce FX series, which was found to be only marginally better than its GF4 series, and was still soundly whomped by the Radeons.
Look at ATI's Radeon 9000-9800 line and find one that fits your performance and cost needs. I wouldn't even bother with the Geforce FX series.
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I checked out ATI. I guess my problem is I can't tell the difference between a 100 dollar card and a 400 dollar card. They both look the same to me.
I don't want to spend the money on "the best", since it will be half the price in less than a year. I want it to be significantly better than my GeForce 2, though.
Any suggestions?
What about my CPU? Any thoughts on that? I just want it to run AHII ok.
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tarmac .. the benchmarks @ tomshardware said the ati 9000 was POS compared to the gforce4ti4600
different story about the 9500 and 9800
9500 about being equal looked like.
yes the 9800 is better... but i wouldnt justify spending that money.
+ im a fanboiy of geforce (cause i HATE ATI from the past... but thats just me. i got a 32mb card for $300 back when it was "supposedly" the best thing available. it was an utter POS with absoultly zero support)
back to topic. Martlet... i have been out of touch with most of the latest updates in processor power and stuff but i swear by AMD personally. much faster and also cheaper.
last i saw an athlon XP1700 was still way faster than an intel 2.2ghz (which is going back a way but look at the difference in mhz between the 2)
oh well like i said im out of touch with the newest and bestest so ignore this post anyway.
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Martlet, take a look at the ATI cards over the FX cards right now. The radeon 9800 or 9700 would be as good or better then them.
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Naw INTEL spanks AMD in the FSB department and thats a BIGGY.
I have mine overclocked 2.4 to 3.6 and FSB from 800 to 1200
You aint gonna get that with a AMD.
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he's recommending the FX5200 series because they are DOGGIE DOO cards.
If NVidia, FX5900, minimum. You can overclock them to 5900Ultra speeds. But if you're gonna spend that much money, radeon9800Pro is better/faster at 90% of all games. Neither one will leave you unhappy, just that radeon is better performance at similar price.
For midrange cards - Radeon9600Pro or XT is the way to go. I'd go with the Pro, not enough difference to justify the extra 30-40 bucks at the moment. The similarly priced nVidia FX5600 series just gets beat all to hell by it.
Note that the differences become aparent more as you turn on/up the quality settings like anti-aliasing and anisotropic filtering.
At low quality settings, the radeon/nvidia series cards are somewhat on par, but as you up the resolutions and anti-aliasing for a better visual experience, the radeons really shine over similarly priced GF cards at this point in time.
As for processor, I just got a barton2500, and I overclocked it by changing the multiplier from default (11) to 12.5 and now have a barton2800 for the price of the 2500 (180 bucks vs 90 bucks) - using stock cooling, too. on the other hand, people who get the 2800s can frequently run it at 3200+ speeds. YMMV.
But the processor upgrade won't give you as big a boost as your vid card - especially if your just going from XP2000+ to barton2500/2800+. insted of dumping the money into the processor, use your old one, and move to the next higher vid card. Then in 3-6 months, when processors are even cheaper, you can pop a 2500 or 2800 or maybe even 3200 in there for a smaller investment.
BB
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But no matter what you do with an AMD you will not be getting 1200 FSB:D
(http://home.comcast.net/~c.hambleton/wsb/media/134502/site1042.JPG)
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*shrug* you had to spend HOW much on that cooling system for that?
*feh*
2.4/2.6 400FSB oc'd to 3.0+ works for most people. Without spending an arm and a leg for a phase change or water cooling system. :p
Its not about pure performance (for me) its about performance/price.
and AMD still wins that one in the midrange processor level, IMO.
Right now, best bang for the buck is an Nforce-2 Ultra400 Mobo, Barton2500, and Radeon9600Pro vid card combo. Sure you can get better performance, but the price curve starts getting pretty steep.
BB
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I'm with you BB on "bang for your buck".
I don't want a new motherboard, since mine isn't bad. I have a MSI KT3 Ultra 333MHz FZB, PC2700DDR
I have an AMD Athlon 2000+ on there now, and I'm just wondering how high I should go to see a noticable difference, without spending a fortune. I know I can put a 2600 and 2800 on there. The 2800 is $100 bucks more than the 2600. Is the difference noticable?
also, I don't know anything about video cards. If you guys say go with an ATI over GeForce, then I'll take your word for it. Which one should I get? I'm not going to spend 300 bucks on a new card. Should I wait until the price of the 2600 Pro goes down next month like Skuzzy said? Is that a noticeable difference over my GeForce 2?
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I would go with the ATI 9600
check them out at http://www.newegg.com
http://www17.tomshardware.com/graphic/20031015/index.html
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Originally posted by BB Gun
*shrug* you had to spend HOW much on that cooling system for that?
BB
I spent 1.100.00 for the cooling system.
But you can buy them cheaper from suppliers in england.
DO NOT buy from USA resellers.
You will pay twice as much like i did:mad:
You can expect to pay 600-700 bucks.
but that is for case and every thing.
http://www.chip-con.com
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Skuzzy says 9600 Pro is the way to go as far as best bang for fewest bucks is concerned. I think I'll go with that and hold him liable. ;)
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Originally posted by Arlo
Skuzzy says 9600 Pro is the way to go as far as best bang for fewest bucks is concerned. I think I'll go with that and hold him liable. ;)
Bingo. That's solid advice.
Any suggestions on the CPU?
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MrBlack, you obvously aren't comparing against the new Athlon 64 chips. The Athlon 64 series CPUs have a 1600 MHz effective link to the Northbridge, which is the closest thing they have to a FSB. It is a 800 MHz DDR Hypertransport link, or 1600 MHz SDR effective. (So I guess you are right, "no matter what you do with AMD you won't get 1200 MHz" - you get 1600 MHz stock. ;) ) Since the Athlon 64s have an on-die memory controller, they don't even have a traditional external Front Side Bus like any other CPU. Their link to the on-die memory controller runs at full processor speed. This greatly reduces memory latency, and along with the 1 MB L2 cache, is the primary reason for their improved performance over the Athlon XPs. When it comes to overall gaming performance, nothing can touch the new Athlon 64 FX 51.
You should be careful comparing Intel and AMD chips based on FSB speed alone. The Pentium 4 'C's use a 200 MHz QDR (quad data rate) bus, which gives an effective rate of 800 MHz. The Athlon XP 3200+ (the "old" Barton core) uses at 200 MHz DDR (double data rate) bus, 400 MHz effective. Notice that the fundamental clock rate is the same. The theoretical latencies of AMDs "400 MHz" FSB and Intel's "800 MHz" FSB are the same. The maximum available bandwidth is the only difference. There are such tremendous architectural differences between the Barton and Northwood cores that affect performance that comparing raw FSB speeds alone really doesn't mean much.
Since the Athlon 64 3200+ and Athlon 64 FX 51 are still out of the price range for most of us, I'd say the best bang for the buck ratio is still either the Intel 2.4 'C' or the Athlon 2500+. Both of these are also highly overclockable. At stock speeds they perform roughly the same, especially in gaming. The P4 has a definate edge in media encoding (video and to a lesser extent audio) and the Athlon has an edge in office applications and scientific/engineering applications.
When it comes to gaming, the video card is by far the main limiting factor. I'd say the best bang for the buck there is going to be either the $199 ATI Radeon 9600 PRO and/or XT or the hard to find $250 Radeon 9800 standard. I personally feel ATI has the edge over nVidia at the moment, but the GeForce 4 Titanium 4200 is still a pretty fast card that can be found for around $120. I don't care much for the GeForce FX series.
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LMAO mrblack ... he was asking about a basic system ...
not some frankenstein 1337 hax0r m4ch1n3 with a cooling system worth more than 2/3 my whole tower.
btw a stock P4 has no chance against AMD period... that i know.
i also know AMD overheat faster while overclocking so thats a totally different conversation.
is that cooling sys freon based?
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Originally posted by Martlet
Bingo. That's solid advice.
Any suggestions on the CPU?
What's the bus speed on your motherboard and RAM?
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Originally posted by mrblack
I spent 1.100.00 for the cooling system.
...
You can expect to pay 600-700 bucks.
but that is for case and every thing.
Case closed.
whats the point of spending 700 bucks on a cooling system to get an extra 15-20% speed?
Your money, your choice. Me, I'd rather get a second system. For 700 bucks, a rather NICE system, too. :p
Martlett - set your price level first. Budget is what you have to set for total cost.
At newegg - ON SALE!
SAPPHIRE OEM RADEON 9800 PRO 128MB DVI/TV 8X AGP Video Card for $301.00 Free Fedex Saver Shipping!
If you opt for a radeon9600Pro and a Barton 2500, you're spending about 250. if you go 9600Pro and a Barton 2800, you're spending about 350.
For that price range, skip the processor upgrade and get the 9800 Pro. I am not sure if the KT333 chipset will change a Barton Multiplier, I'd have to do more research. Manual says it has a BIOS setting for changing CPU ratio, but not sure if it supports Barton-like numbers.
If you set your price level higher, sure, get the 2500. It will only help. :)
BB
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Just read a report on a test of a 9600XT. Now this card comes with a stock core of 500Mhz. This guy got a stable overclock of 212Mhz. Yes, 712Mhz core. Insane.
I am curious as to how well the low-k die will hold up in the long haul. bloom, you have any insight on that?
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Looks like i wont regret buying the 9600XT (Connect3D).. payed 180$ for it... may be cheaper in the US tho.
Getting it on Monday/Tuesday.
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Just to clarify - since you're CPU is already a 2000+, the Radeon9800Pro gives you better bang for buck and better longevity than a radeon9600+barton2500.
If your processor was in the 1 GHz range, I'd have recommended the 9600Pro/XT+barton2500 upgrade path.
My recent experience going from an unoverclockable albatron PX45PEVPro/PIV 1.8 combo (dunno if motherboard or chip, but the thing wouldn't even accept 1 MHz of FSB overclock without crashing the system) to a Barton2500+/Epox8RDA3+ combo overcocked to Barton2800+ specs with same graphics card (Radeon9500Pro) increased my 3dmark scores by about 35%. What it did for gameplay (in WarbirdsIII) was allow me to go from the occasional stutter/blurryness/slowdown through smoke to smooth 60+ framerates under all conditions all the time in WBIII at 1024x768 at 2XAA and 8XAF. But that was an effective 1 GHz upgrade, about a 60% CPU performance increase. Barton2500 over XP2000+ is only a 25% cpu increase, which, if my results are "typical" would only give you a10-15% game performance increase.
BB
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Speed man Greasy speed is where it's at.
And I can pop a prescott in as soon as they com out.
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I don't know how to overclock. My cpu is just how I got it.
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Originally posted by Martlet
I don't know how to overclock. My cpu is just how I got it.
You can over clock buy going into you're bios settings.
But be VERY carefull temp will have to be monitored carefully as not to mess up you're CPU.
If you're not comfortable with doing it DON'T.
Just enjoy you're new rig and have fun.
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Originally posted by JB73
not some frankenstein 1337 hax0r m4ch1n3 with a cooling system worth more than 2/3 my whole tower.
IT'S ALIVE IT'S ALIVE
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Originally posted by BB Gun
whats the point of spending 700 bucks on a cooling system to get an extra 15-20% speed?
BB
The point is I am running at 3.7 GHz
For the price of a 2.4GHz
I am unaware of a faster desktop CPU than that!
Unless ofcoures it's another prometiea cooled 3.2GHz overclocked to 4.3GHz and yes they are out there LOL.
Also when the prescotts hit the shelves I can pop one in and
Over clock that bad boy too!
So it goes on and on forever going faster and faster:aok
If Intel comes out with a 5.0GHz CPU I will have it running at 6.0GHz.
Now do you see my point:D
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Originally posted by Martlet
I don't know how to overclock. My cpu is just how I got it.
Enter the BIOS and change the FSB settings - a 266 FSB will be set at 133 in the BIOS (double rate to 266), or a 333 FSB will be 166 etc. If you increase it, e.g. on 333FSB board increasing it from 166 to 168 will overclock the CPU and so forth - 170 will be even higher (340). The more you increase the more you overclock. If the CPU was a XP2800+ then it'll still show as a XP2800+ but it will be running at a higher frequency.
Don't know how to explain it any easier, I don't know all the 'buzz' words! :)
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Originally posted by mrblack
The point is I am running at 3.7 GHz
For the price of a 2.4GHz
Wrong.
You are running at 3.7 GHz for the price of a 2.4 GHz PLUS ONE THOUSAND DOLLARS.
lessee....
3.2 GHz intel extreme is currently $585.00, 2.4 is $222.00, price differential is approximately 350. So you've spent an extra 700 bucks to get .5 GHz over the current max stock speed. And you're choking the system with a GF4 4600 instead of a modern videocard.
Whatever floats your boat, I guess. I just don't get it. *shrug*
I do guess, over the life of the system, it may eventually pay off over the course of 2,3 or 4 rebuilds, but what are the odds that the parts won't fit new socket designs?
Like I said, I'd rather have the second system than an extra 0.5 GHz.
But you're not me, I'm not you, and that's what makes the world go around. :)
BB
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Originally posted by Replicant
Enter the BIOS and change the FSB settings - a 266 FSB will be set at 133 in the BIOS (double rate to 266), or a 333 FSB will be 166 etc. If you increase it, e.g. on 333FSB board increasing it from 166 to 168 will overclock the CPU and so forth - 170 will be even higher (340). The more you increase the more you overclock. If the CPU was a XP2800+ then it'll still show as a XP2800+ but it will be running at a higher frequency.
Don't know how to explain it any easier, I don't know all the 'buzz' words! :)
Be careful about bumping FSB - it changes PCI/AGP speeds unless your BIOS gives you the option to lock the PCI/AGP speed or change its ratio. Changing the AGP/PCI bus speeds can cause problems with video card and PCI cards.
With the Bartons, the multiplier is unlocked, at least with nForce2 boards. Dunno about KT333 boards. I just changed my multiplier and bumped my processor speed from 1833 to 2083 MHz (=2800+ speed). FSB changes come later when I pass my current RAM to my kids machine and get faster PC3200RAM.
BB
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I'm using a MSI KT6 Delta (VIA KT600) 400FSB capable - there's isn't a multiplier so the only way to overclock is by increasing the frequency of the FSB... unless someone can correct me to an easier way?
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Originally posted by BB Gun
Wrong.
You are running at 3.7 GHz for the price of a 2.4 GHz PLUS ONE THOUSAND DOLLARS.
lessee....
3.2 GHz intel extreme is currently $585.00, 2.4 is $222.00, price differential is approximately 350. So you've spent an extra 700 bucks to get .5 GHz over the current max stock speed. And you're choking the system with a GF4 4600 instead of a modern videocard.
Whatever floats your boat, I guess. I just don't get it. *shrug*
I do guess, over the life of the system, it may eventually pay off over the course of 2,3 or 4 rebuilds, but what are the odds that the parts won't fit new socket designs?
Like I said, I'd rather have the second system than an extra 0.5 GHz.
But you're not me, I'm not you, and that's what makes the world go around. :)
BB
Prometiea offers and will continue to offer cooling heads(the part that makes contact with CPU)
For all upcoming Intel and AMD CPUs.
So it is forever upgradable.
And the P4 2.4 Is $175.00 at http://www.newegg.com
And you can buy the Prometiea in England for $660USD.
I just messed up and bought from US reseller:mad:
Also you have the option of buying the prometiea MAch1 for $550.
So you can get in fairly cheap.
As far as vid card well LOL.
We are building a new house and maybe you do or don't know what that can do to you're money :(
But it is next on my list as far as upgrades go thats for sure.
Looking at that new 256meg card ATI just realeased.
But baby It is expensive:eek:
let me know I can hook you up cheaper than you think for a Prometiea.
:aok
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Let me se if I understand.
AMD=333 FSB Overclock?
INTEL=800 FSB Overclock 1200-1300.
I am no rocket sientist but I think Intel has AMD by the short and curlys on the FSB anyway.
It all comes down to this I think.
Are you a Ford or Chevy man:D
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Originally posted by BB Gun
. And you're choking the system with a GF4 4600 instead of a modern videocard.
BB
1600x1200 all eye candy on
(http://home.comcast.net/~c.hambleton/wsb/media/134502/site1046.JPG)
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Originally posted by mrblack
Let me se if I understand.
AMD=333 FSB Overclock?
INTEL=800 FSB Overclock 1200-1300.
I am no rocket sientist but I think Intel has AMD by the short and curlys on the FSB anyway.
It all comes down to this I think.
Are you a Ford or Chevy man:D
AMD do have a 400 FSB which is comparable to the Intel 800 FSB. AMD is set at 200 (double rate = 400). Intel no doubt have theirs at 200 too but have a multiplier to make it 800... if that makes sense? The AMD can be overclocked by increasing the '200' and dependant on system cooling.
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That's correct Replicant, as I posted briefly above. In case anyone really cares, here's some more info: ;)
AMD uses a 200 MHz fundamental DDR EV6 bus for the Athlon XP 3200+ (400 MHz effective) to the Northbridge. The 2500+ to 3000+ use a 166 MHz DDR EV6 bus (333 MHz effective). The Athlon 64 chips don't even have a FSB, as their memory controller is part of the CPU itself, meaning the closest thing they have to a traditional FSB link to main memory runs at the clockspeed of the processor. They do have an 800 MHz DDR Hypertransport link to the chipset (1600 MHz effective). It's not technically even a northbridge anymore, as there is no memory controller there, it's pretty much only a link to the AGP video card and the rest of the system. The 'C' type P4s use a 200 MHz QDR (quad data rate) GTL+ (gunning transistor logic) bus to link to the Northbridge (800 MHz effective). 'B' type P4s have a 133 MHz fundamental clock (533 MHz effective) and the older 'A' type Northwoods and Willamette type P4s used a 100 MHz QDR bus (400 MHz effective).
Regardless, the FSB clockrate really means almost nothing when comparing two totally different CPU architectures. (Just look at the FSB speed of the Itanium as an example. I don't think anyone can argue that the Itanium is a faster CPU overall than the 3.2 GHz 'C' type P4.) In general, the faster the FSB, the lower the latency for memory accesses and the greater the bandwidth. That means that for a given architecture the faster the FSB, the faster the CPU will perform at the same clockspeed. This only holds true to a point though. To explain why would require a LOT of my time, and I doubt anyone would care enough to warrant me spending the time to explain it. The Pentium 4 is much more sensitive to memory bandwidth than the Athlon XP is and Intel has outfitted the 'C' type P4s with a high bandwidth 800 MHz effective FSB. AMD has done away with the traditional FSB entirely in its new Athlon 64 line of CPUs.
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Originally posted by bloom25
That's correct Replicant, as I posted briefly above. In case anyone really cares, here's some more info: ;)
AMD uses a 200 MHz fundamental DDR EV6 bus for the Athlon XP 3200+ (400 MHz effective) to the Northbridge. The 2500+ to 3000+ use a 166 MHz DDR EV6 bus (333 MHz effective). The Athlon 64 chips don't even have a FSB, as their memory controller is part of the CPU itself, meaning the closest thing they have to a traditional FSB link to main memory runs at the clockspeed of the processor. They do have an 800 MHz DDR Hypertransport link to the chipset (1600 MHz effective). It's not technically even a northbridge anymore, as there is no memory controller there, it's pretty much only a link to the AGP video card and the rest of the system. The 'C' type P4s use a 200 MHz QDR (quad data rate) GTL+ (gunning transistor logic) bus to link to the Northbridge (800 MHz effective). 'B' type P4s have a 133 MHz fundamental clock (533 MHz effective) and the older 'A' type Northwoods and Willamette type P4s used a 100 MHz QDR bus (400 MHz effective).
Regardless, the FSB clockrate really means almost nothing when comparing two totally different CPU architectures. (Just look at the FSB speed of the Itanium as an example. I don't think anyone can argue that the Itanium is a faster CPU overall than the 3.2 GHz 'C' type P4.) In general, the faster the FSB, the lower the latency for memory accesses and the greater the bandwidth. That means that for a given architecture the faster the FSB, the faster the CPU will perform at the same clockspeed. This only holds true to a point though. To explain why would require a LOT of my time, and I doubt anyone would care enough to warrant me spending the time to explain it. The Pentium 4 is much more sensitive to memory bandwidth than the Athlon XP is and Intel has outfitted the 'C' type P4s with a high bandwidth 800 MHz effective FSB. AMD has done away with the traditional FSB entirely in its new Athlon 64 line of CPUs.
Thats a good read.
And I for one would be interested in hearing more.
Thx.
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Working on it as we speak Mr. Black. :) It's already a couple pages, and it's 12:38 AM here now, so I don't know if I'll get it finished tonight or not.
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Here you go! I'll try to condense 4 years of college computer architecture classes down to 1000 words. I just hope that some of it makes sense when I'm done. :D
The first thing I should probably do it explain what a "front side bus" is in the first place.
A "front side bus" is the link between the CPU and the rest of the system, specifically what is typically known as the "Northbridge".
Most chipsets (which are on the motherboard itself) consist of two parts, the Northbridge and Southbridge. The Northbridge historically has contained the memory controller (Sdram, DDR Sdram, Rambus, etc) as well as more recently the controller for the AGP slot itself. The Southbridge typically controls just about everything else in the system. (PS2 ports, USB ports, LPT port, onboard sound, IDE controller, floppy controller, onboard network, etc.) The Northbridge and Southbridge are typically linked by the PCI bus, on which most of the expansion cards in the PC also connect. (There are exceptions to this, as some single chip solutions now exist (Sis chipsets), and sometimes a different separate bus links the NB and SB, as is the case with the nForce chipsets which use a Hypertransport link and VIA chipsets which use "Vlink".) Why does this matter? Basically the front side bus is the critical link between the CPU and the entire system. This means that the faster the FSB is, the faster the CPU can communicate with everything else in the system. If the CPU wants to get data or instructions from system RAM, that data travels over the FSB. If the CPU needs data from the hard drive, that data travels to the southbridge, over the PCI bus to the Northbridge, and then over the FSB to the CPU. As you would expect, the faster this link is, the faster the system will be. If this is true, why would I say that a faster FSB results in diminishing returns in system speed beyond a certain point? I'll get to that. ;)
(BTW for all you tech historians: There used to be a "back side bus" which linked the CPU to it's Level 2 (L2) cache. The term is now obsolete, because just about every modern CPU since the Coppermine Pentium 3 core has had it's L2 cache as part of the CPU itself, meaning the BSB is part of the CPU itself as well. If you want to get really technical, the term front side bus is no longer really valid in its original context, because it is now the only bus.)
Perhaps the first thing I should cover when trying to explain why a faster FSB doesn't always result in a corresponding increase in system performance is to consider the case when the CPU needs data from the harddrive. (Which happens quite a bit when loading programs and when the data the CPU needs does not fit into system memory.) I'm sure all of you know that the harddrive is many orders of magnitude slower in transfering data than system memory is. The amount of delay imposed by the data traveling over the FSB is nearly negligable when compared to the amount of time it takes for the hard drive to retreve and store information. This makes the FSB speed itself very much a non-factor.
The next case is when the CPU needs data from main memory. There are two key concepts to understand here: "Latency" and "Bandwidth".
Latency is essentially the amount of time the CPU must wait between issuing a request for information and when the information actually is available to the processor. This time is generally measured in nanoseconds, but it's far more useful to look at it in terms of clockcycles the CPU executes. This is because the CPU is essentially wasting time during the clockcycles where it is waiting for data and/or instructions from memory. I'll come back to this later, because it is probably the most important thing to understand.
Bandwidth is the amount of data that can be transfered in a given unit of time.
Let's look at this from a more intuitive example. Consider a highway where vehicles travel from one point to another. In this example, bandwidth is essentally the number of lanes of the highway. Latency is essentially its length. Lets say you have a contest to get the most vehicles from one end of the highway to the other. Unfortunately, only a certain number of vehicles can enter the highway per second. This start of the highway is roughly analogous to main memory in a computer. The end of the highway is the CPU itself, and compared to main memory, is far faster. As you can well imagine, if you make the highway shorter (lower the latency) you can get more vehicles to the end (data to the CPU) in the same amount of time as that of a longer highway. Given you can get enough vehicles onto the highway, having more lanes will also get more vehicles to the end of the highway. Consider this though, what happens when you have 800 lanes on your freeway, but only 400 cars can enter it at any given time? Basically, 400 lanes are wasted. (Ok, enough car talk. ;) I'm getting bored with it... )
Real memory in a computer cannot transmit data continuously. It takes a certain amount of time from when the CPU (or more correctly the memory controller in the Northbridge acting on behalf of the CPU) requests data, until when the memory can begin sending that information. This amount of time is the memory latency. To read data from DDR SDRAM memory, which is arranged as a giant grid of both rows and columns, it takes a certain amount of clock cycles to charge the individual cell the data is in (precharge), a certain amount of time to activate the row the data is in (RAS - row address strobe), and a certain amount of time to access the column the data is in (CAS - column address strobe, a term most people who buy memory have heard.), the final factor is the command rate (time between issuing a command to memory to when the command is executed, usually only a cycle or two). All of this is what is collectively known at memory latency. (You see this printed on memory and on review sites as a string of 4 or 5 numbers.) The lower the latency, the less time it takes for the memory to begin transfering data to the northbridge. DDR memory currently runs at 100 Mhz - PC1600, 133 Mhz - PC2100, 166 MHz - PC2700, and 200 MHz - PC3200 as standard rates. The latency is measured in the number of memory clock cycles. (You probably think I'm wrong here, and that PC3200 memory runs at 400 MHz. That's not actually true, and I'm getting to that.) DDR memory (double data rate) has the capability of transfering data on both the rising edge (low to high) of the clock pulse and on the falling edge (high to low) of the clock pulse. If it could do this all the time, it would have the same bandwidth as regular SDRAM, which transfers data on only the rising (low to high) clock edge. This is why PC3200 is also known as DDR400, because it is capable of transfering, at a maximum, at the same bandwidth as SDRAM running at 400 MHz. This also explains why you sometimes see DDR memory with a CAS latency of 2.5 cycles, this means the data can access that column after 5 clock edges (rising or falling). DDR memory can transfer data on both the rising and falling edges when it is performing a burst transfer of more than one location in memory. Most of the time it does, and there is a very good reason for this. Typically when a CPU wants data from memory, the next access from memory will be from a location very close to that of the first access. For this reason, SDRAM (and the older fast page memory) will transfer the entire contents of the memory row. This boosts performance, because if the CPU does end up needing data in the next cell, that data has already been transfered. If it ends up the access is not from the same row, nothing is really lost, as the CPU just discards the data it doesn't need. Note that I've hugely simplified this. This is what is known as "spacial locatity" in computer architecture classes, which basically says that a CPU will most request data from memory in a location near the last access most of the time. Basically SDRAM and DDR SDRAM assume this and just transfer all the data near to what the CPU requests. Wow, that's a lot of information to try to condense and "dumb" down, but hopefully those of you who stuck with it now better understand what memory latency is.
Now, lets briefly touch on bandwidth. Individual DDR memory modules in modern computers are 64 bits wide, meaning they transfer data in 64 bit chunks on both the rising and falling edges of their data clock. This is the amount of data transfered over a single channel. If we are talking about a DDR 400 module, this bandwidth will be 3.2 Gigabytes per second. If we have two independant channels (dual channel) transfering data at the same time this will be 6.4 Gigabytes per second.
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(Too long for a single post)
Consider this: For best performance, the CPU's FSB should be capable of transfering data at the same rate as which it can be transfered at a maximum from main memory. For the case of Dual channel DDR400 (PC3200) memory, this is 6.4 GB/sec. The bandwidth offered by the P4 'C' type 800 MHz equiv. FSB is 6.4 GB/sec. You can imagine that if the FSB was slower than this, you'd have a traffic jam with dual channel DDR 400 memory when both channels are transfering at the same time. This means you are losing performance. (This is why a 'C' type P4 performs best with dual channel PC3200 memory.) The opposite case is also true, if the FSB is capable of transfering more data than the ram is capable of delivering, you aren't gaining much performance by having the capability to do so. This is the case on many systems. Consider a 'C' type P4 with an 800 MHz FSB, but using only PC2700 DDR333 modules. If you neglect the influence of Hyperthreading, the 'C' type P4 will perform no better than the 'B' type P4! This is also true with Athlons. Thus we have two cases where we are losing potential performance - faster memory than FSB, or a faster FSB than memory. Thus, the best system memory performance occurs when the FSB is equal (or faster) than memory. If it is faster you don't gain much though, and in fact may actually lose performance because the Northbridge must wait to transfer data from the CPU's FSB and memory bus until the next clock edge. This adds latency. This is why a Athlon 2500+ (333 MHz FSB) runs slower with DDR 400 memory than it does when using DDR 333 memory. The Athlon architecture is very sensitive to latency, more so than a P4.
I'm afraid I'm going to have to stop here for the night. It's 1:20 AM and I need to get up in 6 hours. At this point I haven't tied all the loose ends up, but I think you may begin to see where this is going. Tomorrow I'll try to post about neat little things like: Hyperthreading, integrated memory controller, hardware prefetch, cache memory influence, and if anyone actually reads and gets something from this, maybe more! :D
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Since it may be a while until I get around to this tommorow, I think I should mention this:
The 'C' type P4 has a 800 MHz FSB, with enough bandwidth capable of handling the amount of data transfered from two channels of DDR 400 memory. As I mentioned before, SDRAM type memory transfers the entire row of data, which means that in a dual channel setup two entire rows of data will be sent for each memory request. If the CPU doesn't actually need all of that data, the benefits of transfering all of it, and thus the performance advantage of a 800 MHz FSB over that of a 400 MHz FSB (single channel DDR 400) is wasted. Remember that the CPU simply throws away what it doesn't need. To be technically correct, it stores all the data in it's L2 cache (L3 as well if it has one) until it runs out of room, in which case it dumps the oldest data. It also must discard portions or all of its data stored in cache when it writes back to memory. (If a CPU needs to write to memory, the data in the cache which was transfered from the location it wants to write to is no longer correct, and is discarded. The cache can also be flushed when the CPU switches processing from one thread to another. If this sounds related to Hyperthreading, it is, and more on that tommorow... :) )
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Bloom get outa bed now ! :D
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Saved ... this guy is MAW? :D
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To go farther on this I think I'll have to dig into CPU architectural differences between the Athlon, Athlon XP, and new Athlon 64 cores versus the Pentium 4. Because of the architecture of the Pentium 4 vs the Athlon, the Pentium 4 spends a lot more time waiting for data to be read from and written to main memory than the Athlon. This makes it more dependant on the FSB. I know you guys would probably never forgive me if I left it at that, so I think I'll probably just start a new thread and repost what I've got here and expand on it. I think if I keep going here I'll REALLY be hijacking this thread.
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Hi mister Mrblack, i run a ASetek wapochil, and a AMD BARTONis it a 2800 + clocked on the needs i have, well i can puch it around 3.2 Ghz or up , all the rest is coled be ASetek Waterchil, well for me the big problem is the DDR3500 2 x 512 CORsair , they owerheat to much i thing, i have a home made big pasive colers glued on the RAM, surface, i removed the originals plates , and glued the new one , also have to use a Voltage modifications on my ASUS deluxe board i have the REV 2 , discovered that even using onboard Sound card on Nvidia chips set, giving trouble, after instaling Audigy , stable, beter, using the ATI 9700 PRo what i bought last Xmas thx to the Scuzy sugestion cose i was ready to buy a MATROX parhelia, at November last year but got a nice tip from Skuzy,
IF u run a real high end all the CRAP around super uber PSU 550 W and up + all voltage mods + ram coling + Chip set coling to get the thing roling fine , for me it was a litle chalange but now it works fine, waiting for the AMD 64 FX 51 to show up if price go around 600 EURO i em a buyer and i again ask do u people have problem coling rams ? cose i have and big time :D
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Hey Bloom , Great post about pc cpu's . I even under stood most of it ...(I just wanted to say thanks over here then muding up your post ) :aok
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:eek:
wow thanks bloom :cool:
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Originally posted by minus
Hi mister Mrblack, i run a ASetek wapochil, and a AMD BARTONis it a 2800 + clocked on the needs i have, well i can puch it around 3.2 Ghz or up , all the rest is coled be ASetek Waterchil, well for me the big problem is the DDR3500 2 x 512 CORsair , they owerheat to much i thing, i have a home made big pasive colers glued on the RAM, surface, i removed the originals plates , and glued the new one , also have to use a Voltage modifications on my ASUS deluxe board i have the REV 2 , discovered that even using onboard Sound card on Nvidia chips set, giving trouble, after instaling Audigy , stable, beter, using the ATI 9700 PRo what i bought last Xmas thx to the Scuzy sugestion cose i was ready to buy a MATROX parhelia, at November last year but got a nice tip from Skuzy,
IF u run a real high end all the CRAP around super uber PSU 550 W and up + all voltage mods + ram coling + Chip set coling to get the thing roling fine , for me it was a litle chalange but now it works fine, waiting for the AMD 64 FX 51 to show up if price go around 600 EURO i em a buyer and i again ask do u people have problem coling rams ? cose i have and big time :D
Ya Ram seems to be the limiting factor in our setups thats for sure.
We have the heat issue taken care of You might try some Mushkin pc3500 2x256 it is the BH-5 chips and I am having good luck with it.
Can get 315 FSB but for stability i run 300FSB.