Author Topic: PCI Express, wait to upgrade or not? (Read 683 times)

MOSQ · « **on:** June 23, 2004, 10:17:20 AM »

I posted this in Bloom's PC thread, but I'm sure only 2% of the BBS folks will read all the way thru it, so here it is as it's own thread question:

I just noted that Dell is now selling the Dimension 8400 in PCI/PCI Express only using the 925x chipset. The AGP slot is gone!

Where the market leader goes the rest of the industry will shortly follow.

So the question for everyone who is looking to upgrade because of AHII: Should they wait for PCI Express mobos and cards to be available widely, or go ahead now with AGP?

The question is important because future video cards starting with the top end ones will be PCI Express, not AGP. In a couple of years all the new cards across the price range will be PCI Express, with only low end cards still AGP.

If you can buy a Dell today with PCI Express, you'll see mobos and vid cards galore by Christmas. My system today plays AHII ok, so I'm not in a forced "right now" upgrade.

From PC Mag:

In the most significant bus transition since PCI replaced ISA, PCI Express arrives with the new chipsets. Similar to the way hard drives transitioned from the parallel IDE connection to the serial ATA (SATA) connection, PCI's parallel connection is moving to PCI Express's serial connection. While a typical 33-MHz, 32-bit PCI bus has a unidirectional total bandwidth of 133 MBps (megabytes per second), each pair of wires on PCI Express is capable of transferring 2 Gbps (gigabits per second) in both upstream and downstream (read and write) directions for an effective total bandwidth of 4 Gbps—or 500 MBps.

Since PCI Express is a point-to-point serial connection, that bandwidth is available for each card connected to it, rather than being shared among all the cards as it is for PCI. These pairs of wires can also be grouped together to make x1, x2, x4, x8, x16, and x32 (pronounced "by 1, by 2" and so on) connections, with each pairing doubling the throughput.

Notably, the next generation of high-end graphics cards will no longer be on the 8X AGP bus but on the x16 PCI Express bus. Today's 8X AGP graphics bus has a unidirectional bandwidth of 2 GBps (gigabytes per second). With x16 PCI Express, bandwidth is 4 GBps in each direction, for a cumulative bidirectional bandwidth of 8 GBps. Besides graphics, the 915 and 925 chipsets will also support up to four x1 PCI Express slots in addition to up to six PCI slots.http://www.pcmag.com/article2/0,1759,1615226,00.asp

Skuzzy · « **Reply #1 on:** June 23, 2004, 11:02:27 AM »

While it all sounds really good, there is no real performance advantage for PCI-E today. To take advantage of the features, the operating system structure has to change. It will be a while.

There is a major downside to the Intel 925 chipset. They are switching to a new CPU socket. The 775, which has the pins for the CPU mounted on the montherboard. The CPU uses resistance to hold in place.
Intel specs the instertions at 20, before damage to the pins is done. Easy to damage the socket as well.

Overall performance is not really any better than the current 875 chipset either. I really see no point to it at this time.

MOSQ · « **Reply #2 on:** June 23, 2004, 12:03:04 PM »

Thanks Skuzzy.
I wasn't really looking for a performance advantage today, but future upgradability.

It appears as I read more and more that the PCI /AGP bus will be going legacy like the ISA bus faster than many people expect. That means that the new top line video cards, and shortly sound cards, will be PCI Express.

There are already motherboards being made in PCI Express for the Athlon 64 too, they should be available by late fall.http://www.anandtech.com/mb/showdoc.html?i=2075

So if you want a MOBO you can upgrade for the next three years, it looks like it makes sense to wait a few months and get a PCI Express one if you can fly ok in AHII now.

Many MOBO makers are also Video card makers and Video card GPU chip makers are mobo chip set makers. They have a vested interest in supporting PCI Express as the new standard to force consumers to buy all new gear. I expect new advanced feature boards and video cards will be offered in PCI Express only , so you won't have much choice.

At the ATI and Nvidia websites they are gushing all over themselves about their PCI Express support. I'll bet in 12 months neither of them will offer a new medium or top line price point card in AGP. AGP will be relegated to the low end cards.

Skuzzy · « **Reply #3 on:** June 23, 2004, 01:00:55 PM »

Well, you are right about PCI-E taking over faster than PCI/AGP did. The video card companies are already producing PCI-E based cards for the high end cards.
It is pretty well accepted than PCI-E will take over in about a year.

I hope they speed it up though. Right now it is 4 times slower than a 64 bit PCI-X bus in terms of raw data rates.

The big plus is for the computer and motherboard manufacturers. It will allow them to build the motherboards much cheaper than with a parallel bus.

RTR · « **Reply #4 on:** June 23, 2004, 01:14:12 PM »

Whatever ends up being the standard type, I am sure that I will not end up with it.

I mean, back in the early '80's I bought a Betamax!

RTR

XtrmeJ · « **Reply #5 on:** June 23, 2004, 05:12:08 PM »

Alienware offered this new PCI Express a few days after I ordered my new comp. I was kicking myself in the head! Since it isnt very much of an advantage today I guess I'm fine. I can handle upgrading in a year or so hehe.

Skuzzy · « **Reply #6 on:** June 23, 2004, 05:27:57 PM »

Let the bleeding edge guys sort it out. When they find out it it is slower than the previous bus, they are not going to be happy.

XtrmeJ · « **Reply #7 on:** June 23, 2004, 05:30:01 PM »

Kev367th · « **Reply #8 on:** June 28, 2004, 12:41:16 AM »

As the 8 x AGP bus is not even saturated yet I can see no reason to upgrade to a faster bus that won't be fully utilised. Remember the 4x - 8x AGP promises, none of which came to fruition.

FOGOLD · « **Reply #9 on:** June 28, 2004, 05:05:10 AM »

I am fairly confident I will wait till PCX and BTX boards are fully out before upgrade. The problem is, the killer apps arn't there yet. Half Life 2. When? Far Cry is amazing but my XP2000/ 9800Pro runs it absolutely fine.

Flipping Halo is the toughest game to run and it's graphics are ancient.

FOGOLD · « **Reply #10 on:** June 28, 2004, 05:10:29 AM »

I am fairly confident I will wait till PCX and BTX boards are fully out before upgrade. The problem is, the killer apps arn't there yet. Half Life 2. When? Far Cry is amazing but my XP2000/ 9800Pro runs it absolutely fine.

Flipping Halo is the toughest game to run and it's graphics are ancient.

JB66 · « **Reply #11 on:** June 28, 2004, 11:33:50 AM »

Here is a link to Guru3d concerning SLI and PCI express. Definitely something to look forward to.

http://www.guru3d.com/newsitem.php?id=1628

MOSQ · « **Reply #12 on:** June 28, 2004, 11:54:47 AM »

Quote

Originally posted by Kev367th
As the 8 x AGP bus is not even saturated yet I can see no reason to upgrade to a faster bus that won't be fully utilised. Remember the 4x - 8x AGP promises, none of which came to fruition.

Kev, the issue I'm trying to raise for discussion is not whether the new bus will be a performance upgrade now. I doubt it will make hardly any difference in the near term.

The issue is future upgradeability. If you were around when we all made the switch from add on Voodoo 3-D cards on PCI (yes I still have my Voodoo card and the cable that ran between the Voodoo 3-D to the regular PCI video card) to AGP, then you remember much of the same debate.

From what I've seen so far, PCI Express adoption is happening much faster than AGP did. I truly believe that you will be stuck with a system that has very limited upgadeability a year or at most two years from now if you buy a AGP/PCI board today.

Some folks have to upgrade today to make AHII work, in which case AGP/PCI may make sense. But if you can wait six months, I think it's best to go for PCI Express.

Kev367th · « **Reply #13 on:** June 28, 2004, 03:38:38 PM »

Can't see it being a performance upgrade now, nothing can take advantage of it. I believe a few boards 'may' be a hybrid with both AGP and PCI-E on them.
If I did change would wait for a few months till the Athlon 64 PCI-E boards are available.
Of course its gonna be the future and it is being jumped on by the major manufacturers, but as to when it will be worthwhile, who knows.
As I upgrade every year not really gonna be a prob for me.

I remember the Voodoo, had 2 pci Voodoos running with SLI was sweet for that time.

Siaf__csf · « **Reply #14 on:** July 02, 2004, 04:20:40 PM »

From what I've read, PCI-express has quite a few downpoints and the only real reason why manufacturers push it are the cost savings it creates.

PCI-X uses a parallel connection which means that if the system has even a single slower (normal) pci-slot in use, PCI-X will slow down to the same level with it.

Second problem is the lack of GART driver on pci-x, it severely impacts graphics performance yet more.

As AGP4x is more than enough for any current high-end displaycard, I wouldn't give pci-x a time of day. AGP does not need replacing, at least for a year or even more.