Yum. First we have the 5:4 divider, both at good timings. We can immediately see PAT doing it's thing here, and the good news is, it works asynchronouly as well.
Next, at 1:1. This really is some nice stock-performance here, folks...what's funny is, I 'felt' like I was already overclocking, just because of the 200 front-side bus (I mean, this used to be holy grail material with 533 parts). This feeling went away quickly, though, I'm happy to say.
I said I'd come back to that CAS Latency thing earlier...that's where the column on the end comes in. As I said (and others have done complete reviews on), it really doesn't matter when PAT's latency enhancements are in effect. Sandra has a mini-picnic, but everything 'real' just yawns...heck, some benches are even slower. I will note, though, that with the 865PE (and inherently, the 875PE with a 533 proc...i.e, no PAT), CAS Latency does actually matter. It's a small difference, but it's there.
This is a good time to go into memory timings with the new boards, actually. The most sensitive seems to be precharge delay/cycle time again, just like with the Athlon. This should be the first to go...and amazingly, I actually got a corrupt OS when pushing higher with this setting low (this actually made me happy, in a sic way...of course, I'm disturbed).
It doesn't actually do much for performance, though...I was able to overcome the drop from 6 to 7 with 1 point of FSB. So I just left it at 7 permanently. The next most sensitive was CAS Latency...I was able to hit 212 before I had to drop this to 2.5. And again, there's practically ZERO difference in anything but Sandra with this setting...so unless you're that freak that 'plays' Sandra all day, just set it to 2.5 and forget it (I really don't like Sandra...I just include it for reference). The next most sensitive setting is RAS-to-CAS. Dropping this one actually made a difference. However, it also let me take off quite nicely with raw memory clockspeed. 218 1:1 was the best I could do with it at 2, but I could hit 230 with it at 3. Very nice. Basically, if you can, run this one at 2, but if it hinders you by 2 points of FSB overclocking or more, go ahead and drop it to 3. RAS precharge makes a difference as well (less than RAS-to-CAS), but I didn't find it sensitive at all. In fact, when I dropped it, I couldn't go any higher...so, basically, leave it at 2. Memory timings overall really don't make a huge difference with the 875P in general...I'll save you the pain of 27 charts worth of benches, and just say the average difference between 2.5/7/3/3 and 2/5/2/2 was a measly 0.5-2%.
Hey, this is a good time to look at those fancy memory dividers...
Memory dividers...
Wow. I found this one really interesting...and breaking it out into percentages really made it hit home. The first percentage row shows the individual differences on each benchmark when dropping from 1:1 to 5:4. The Composite figure is simply those seven percentages divided by seven.
That's right, folks...the drop from 1:1 to 5:4 is an average of 2%. Overclockers everywhere should be smiling about right now.
In the third score column, I dropped to 3:2, and the following percentage columns are the percentage drop of 3:2 from 1:1 and 5:4, respectively.
3:2 is a 4.91% drop from 1:1. And 3:2 is a 2.85% drop from 5:4.
This whole chart actually shocked me...but in a good (GREAT) way. I was expecting MUCH greater hits. I'm SO glad to be wrong on that one
Good, good stuff...let's roll on...
Different levels of 3000MHz...
Another neat one. 3 G's with the 533 and 800 parts on both boards.
800's where it's at, folks. And PAT makes it that much sweeter.
Hyperthreading or not...
Hyperthreading, as cool as it is, has been known to hinder benchmarks a tad. I left it off in all these tests as well, because I wanted to compare the 2.4's directly (i.e. the 533 doesn't have it).
What I DID find cool here is, the 'HT hit' was practically zero on the 875P board...nice! Maybe a little PAT side-benefit here? Whatever it is...coolness.
Ok, let's bring on the finals...
'You always saved the best for last'...
There's the whole gang again, in their Sunday best.
Truth be told, these are all really strong, but the clear winner is the 875P/800 FSB part. And there's some headroom in there...I got to Windows in the 280's, and could even pass benchmarks. 3250/271 is the best I could say that it was 100% stable, with Hyperthreading on as well. Pretty damn swanky for a stock-Intel heatsink accomplishment.
Now, I'm gonna dive in real deep. I hadn't really seen this out there yet in this kinda of detail, and was always curious, so I did it...enjoy:
Getting freaky...
I wanna see exactly where all of these gains are coming from.
Furthermore, I want to see it AMD versus P4 style.
Sooo...
Clockspeed + FSB scaling...
PHEAR my mighty hyperthreaded dual-channel P4 1.6GHz!!! Man, that benchrun felt like an oldschool timewarp. Glad it didn't last long.
This represents a 50% overclock for both procs, both equal clockspeeds and FSB's. Again, in each percentage column is each benchmark's benefit, with the Composite being the average. The Efficiency percentage is the composite percentage gains divided by the actual overclock, 50%. Cool, eh?
Both are quite efficient...the P4 gained a little more. I think what we're seeing here is the P4's longer pipeline starting to pay off. While it's not so good at low clockspeeds, it gets better as you ramp it up.
Note those 3DMarks...this is telling us it's time for bigger, badder video cards. The next 'leap' is going to have to come from our friends at nvidia and ATI. This becomes painfully obvious as the CPU clockspeed rises.
Let's break it down even further...
Raw FSB scaling...
Here we have simply a 50% FSB gain...clockspeeds for both are the same.
Quite interesting, no? The Athlon gains a higher benefit from raw FSB gains. A fair guess would be because AMD's FSB is dual data rate, versus the P4's being double that (quad data rate). In any event, they both like FSB, and it's more important to the Athlon.
Once more into the fire...
Raw clockspeed scaling...
The script is flipped. What we have here are equal 50% clockspeed gains, with both FSB's being equal. The P4's gaining roughly 10% more out of it's clockspeed gains than the Athlon, at an efficiency clip of nearly 20% better.
It appears that the P4 still has a pretty good ways to go, while the Athlon line is nearly played out. Perhaps if AMD could figure out a way to go quad-FSB...but we already know they've got their eggs in the Hammer-basket.
In the last roundup, we had a virtual draw. This time around, I've got to hand it to the 875P and the 800 FSB P4 parts. The benchmarks show it. Furthermore, and to some of you, more importantly, the 875P/P4 has too many 'intangibles'....kick-butt stuff that doesn't show up in benchmarks:
-CSA Lan: The Athlon/nForce2 doesn't have an answer for this. CSA Gigabit LAN hauls butt, but even better, it's got it's own dedicated bus. You do not have to worry about flooding your PCI bus with CSA Lan anymore. You can get Gigabit with the AMD setup, but it will be on the PCI bus.
This feature isn't all that important to me, nor the majority of home users, but for those with pretty intense networking needs, this is a deal-breaker.
-ICH5/ICH5R: ICH5 supports two SATA ports natively....nForce2 does not. Furthermore, both those SATA ports, as well as the ATA100 ports, are no longer on the PCI bus either. Intel went out of it's way to clear up some bottlenecks, and it shows. Lastly, the ICH5R version supports RAID 0 (and in the future, RAID 1). Here's the thing...each of those SATA channels is it's own bus. That's right, combined together, it's 300MB/sec of potential (well, 266MB/sec is the limit of the bus, but it's not like we'll be there any time soon):
That's a pair of 10k SATA Raptors, folks...on the onboard SI controller with the nForce2, on the ICH5R controller with the 875P. Note that PCI limit for the nForce2's buffered read. Then note that better-than-single-channel-SATA150 161MB/sec the ICH5R puts out...all the while not being on the PCI bus. Good stuff.
-Hyperthreading. Virtual dual-processing. It's now for the masses, available on all 800 FSB parts down to 2.4. This, to me, is still the big one, and still the hardest to describe. Again, the best example I can give is, this is an All-in-Wonder Radeon 9700 Pro. With Hyperthreading on, I can start capturing video, fire up Comanche, and not drop a frame of video.
If I turn off Hyperthreading, or do this on the Athlon/nForce2, I drop 30-40% frames...i.e. pure garbage video. And it doesn't have to be as strenuous a task as Comanche is...I can fire up Quickbooks or Excel without Hyperthreading, and get frameloss. Heaven forbid I compress a file or something like that. In a nutshell, Hyperthreading makes mulitasking smoother overall, and actually makes some actions possible that weren't before. You'd have to go dually with Athlon to accomplish that.
