ATI PCI-Express Devices Revealed

JohnQ writes "According to Xbitlabs and AnandTech, the specifications for ATI's newest graphics cards have been revealed. Interesting to note is that all of these next generation video cards will run exclusively on the PEG (PCI-Express x16) interface. This does not bode well for those of us who just paid top dollar for the last generation of AGP cards. Read more about the roadmaps on Anandtech and Xbitlabs"

Comments

For those of you like me...

[zegebbers]

who know nothing about this so called PCI Express x16, check out these useful sites... True, they're not in english, but as if it's any harder to read than xbitlabs and anandtech ;-) .

Re:For those of you like me...

[wowbagger]

In a nutshell:

PCI, AGP, and ISA are all parallel systems - you have a wire for each data bit.

PCI express uses a VERY high-speed serial bus to carry the data. How high speed? One serial channel will carry more data than a standard 64 bit 66MHz PCI bus.

The advantages to a serial system are:

1. No timing skew. With a high speed parallel bus, you have to insure that all the data paths are the same electrical length, or else some bits get to the card before other bits, and you have to reduce the clock rate to prevent errors. With a serial system you have far fewer lines to worry about.
2. Simpler board design. When you are dealing with a 64 bit data bus, 64 bit address bus, plus control lines, the board design gets a bit complex. With a serial system, you have less than ten lines per channel - a much simpler board layout.
3. Serial systems usually use a MUCH lower signaling voltage, resulting in MUCH lower EMI and on-board noise.
4. PCI express allows you to gang serial channels for more bandwidth. Video card saturating one channel? Use two.
5. Unlike AGP, PCI express is a bus - so each device can busmaster to system memory or to other cards as needed. This helps you when your video card wants to store textures in system RAM rather than on-card. Imagine how much fun John Carmack could have with a video card that can support 1G of textures.
6. It is far easier to design disconnects for a serial bus, thus allowing for PCI hotswap. In fact, the PC card group is working on a new standard for PC cards (nee PCMCIA) that brings 2 PCI-X channels to card - Cardbus on steroids.
7. It is possible to route a PCI-express channel out of the computer case to an external chassis. While this is of limited use to the usual computer user, for guys like me it is a boon to be able to have an external chassis that looks just like it is on the main system bus, because it IS.

PCI express *could* allow you to have a computer that has bays that accept anything - hard disk, video card, extra CPU, NIC, whatever, and plug them it without restarting (unless you are running Windows (cheap shot, as I beleive MS is working on fixing that)). It will allow your video card to REALLY have fast access to system RAM, and especially in 64 bit systems, that could be a LOT of system RAM.

Good stuff - I can hardly wait 'til it becomes commonly accepted.

Um, no

[thetzar]

JohnQ, are you some kind of idiot? If you READ the article, you'd see that ATI is releasing dual chipsets of identical performance, one each for PCIe and AGP.

Re:buyers of last-gen AGP cards?

[ckotchey]

Note that there are two differnet standards - PCI-X is different than "PCI Express".

Re:buyers of last-gen AGP cards?

[DrMindWarp]

PCI-X != PCI-Express

Check out PCI-SIG.

Re:Drivers

[parksie]

Linux 2.6 + XFree86 4.3

Enable the "radeon" DRI driver in the kernel, use "radeon" in your XF86Config, and all is good. If you want to stick with 2.4, *disable* all DRI support in-kernel, and grab the DRI project R200 drivers.

Re:PCI-E about features

[LankyBoycie]

Nope - AGP can go both ways too, this is not a new feature on PCI-Express. PCI-Express is all about replacing PCI and AGP with a common interface.

Using the host processor "to make on the fly corrections to the image" would be madness as you would have to transfer the whole frame buffer off the GFX card to host mem and then back again. An incredible waste of bandwidth when you can do pretty much most things with pixel shaders anyway, without the round trip.

Re:Cheaper prices

[JPriest]

"ATI's GPUs will be available in both PCIe and AGP flavors throughout 2004."

I guess even the submitter did not RTFA.