PCI Express, the next Graphics Revolution

[manitoubalck]

I submitted a thread a short time ago about the new BTX format of motherboards, but more importantly the move from AGPx8 to PCI Express. “FuzzyBallz” replied “how do you know ATI and nVidia don't already have a prototype 16x PCI-Express card?

Well here’s the proof, acquired form www.nvidia.com and www.Ati.com

 

[manitoubalck]

Here's Ati's

 

[bousozoku]

That doesn't confirm that they've abandoned the AGP slot, just that they're committed to PCI-X.

 

[tomf87]

<PCI-X ignorant reply>

Even still, is PCI-X faster than AGP for graphics? AGP has direct access to system memory, where PCI has to go through the proc. I assume PCI-X is the same?

</PCI-X ignorant reply>

 

[legion]

Not PCI-X, we're looking at PCI Express.

These two (despite similar names which are bound to confuse future consumers) are different technologies. The bandwidth and way PCI Express operates is really nothing like the original PCI (and therefore PCI-X which is just a higher bus rate on the same PCI) The PCI-X on the G5 was already somewhat of a "on the way out" technology when announced, which raised some eyebrows as to why Apple wasn't considering skipping ahead to PCI Express. PCI-X has been out at least a year in workstation motherboards.

PCI Express is much faster than AGP and will probably be used in the future for system interconnects (I'm referring to "inter" not "intra"; just wanted to be clear about that) as a means for board expansion to external boxes. Video cards are the first step to a broader offering.

 

[nuckinfutz]

PCI Express is "Serial" PCI.

PCI-X is still Parallel. That's the biggest differentiator between the two.

Direct Access to memory(DiME) means nothing when you have cards with up to 256MB of memory. Very few AGP cards use DiME.

 

[BenRoethig]

PCI-Express is going to rock. It offers over twice the speed of AGP 8 and the longer 16x slot is compatible with existing PCI and PCI-X cards. PCI Express 16x also allows multiple high speed video cards. Read this article

 

[Lanbrown]

Originally posted by tomf87
<PCI-X ignorant reply>

Even still, is PCI-X faster than AGP for graphics? AGP has direct access to system memory, where PCI has to go through the proc. I assume PCI-X is the same?

</PCI-X ignorant reply>

AGP is not all that different from PCI. Some of Intel chipsets had two buses, one was PCI and the other could be used for AGP or PCI. If an OEM wanted to have two PCI buses, they would buy the same chipset as someone that wanted PCI and AGP. Intel was talking about taking some portions of AGP and putting them on PCI-X.

 

[Lanbrown]

Originally posted by legion
Not PCI-X, we're looking at PCI Express.

These two (despite similar names which are bound to confuse future consumers) are different technologies. The bandwidth and way PCI Express operates is really nothing like the original PCI (and therefore PCI-X which is just a higher bus rate on the same PCI) The PCI-X on the G5 was already somewhat of a "on the way out" technology when announced, which raised some eyebrows as to why Apple wasn't considering skipping ahead to PCI Express. PCI-X has been out at least a year in workstation motherboards.

PCI Express is much faster than AGP and will probably be used in the future for system interconnects (I'm referring to "inter" not "intra"; just wanted to be clear about that) as a means for board expansion to external boxes. Video cards are the first step to a broader offering.

When there are no cards to use it, it makes little sense to implement it. Especially when they will have newer version of the G5 out by the time PCI Express starts picking up some steam. Next thing is if ATI and NVIDIA will have PCI Express cards out for the Mac anytime soon.


Infiniband is still very much a contender as well.

 

[nuckinfutz]

It's a little hard to get excited about PCI-Express. While the bandwidth sounds great and it will be much hyped the facts are the current cards do not saturate the current 8x bus and won't for some time(faster not more memory is required).

Apple will move to PCI-E eventually but I can tell you right now that you will have PC users crowing about the lack of support initially which will be totally asinine as I'm willing to bet money the PCI-E cards are not significantly faster than their AGP counterparts.

 

[benixau]

Originally posted by nuckinfutz
……… I'm willing to bet money the PCI-E cards are not significantly faster than their AGP counterparts.

yes but any hardcore gamer wil ltell you - if it gives me another FPS, just one even, then i expect to pay nothing less than $400 for it.

 

[MacsRgr8]

Originally posted by nuckinfutz
It's a little hard to get excited about PCI-Express. While the bandwidth sounds great and it will be much hyped the facts are the current cards do not saturate the current 8x bus and won't for some time(faster not more memory is required).

Hell... they don't even saturate the AGP 4x bus (well, at least not the Radeon 9800 in a Dual G5 2.0 Ghz...which should be fast enought to actually use that kind of bandwidth)

According to these speed tests the Retail Radeon 9800 (AGP 4x), beats the Radeon 9800 OEM (AGP 8x) in the same Dual 2.0 GHz G5.

 

[ZinK]

Missing the point

I realize that the advent of any new technology is usually greeted with a little bit of skepticism because:
we do not want all our old toys to become worthless
we do not want to risk money on an unproven new technology

In the case of PCI-Express, we ask the following questions:
who needs that much bandwidth when we do not saturate the current standard?
what manufactures will produce cards for PCI-Express?
what price premium will we pay for this new technology?
what gains will be seen for that premium?

Processor speeds have increased just as Moore dictated they would. The existing PCI bus has been around since the early 90’s. It is simply time to speed things up and PCI-Express is a great solution for the following reasons:
Serial devices do not need equal length tracks so motherboard design is simplified
Serial devices are scalable (add more tracks for more throughput)
Serial cards require less “real-estate” and therefore should be cheaper to produce
Serial cards are hot-swappable and hot-pluggable
As clock speeds increase, cards get faster and backwards compatibility is simple

Those are just a few of the advantages of PCI-Express.
Some people have said that the current AGP bus is not being saturated, and that may be true but the current PCI bus is being saturated. Picture having a PCI full-duplex gigabit Ethernet card as well as a PCI SATA raid card. Those 2 devices will saturate a PCI bus and PCI-X is only a band-aid fix.

I think the largest advantage will come as a result of being able to run more than 1 high speed video card as well as all other peripherals on the same bus without any bottlenecking. I currently run a dual monitor setup on a Radeon 8500 and I run into resolution and refresh rate issues. Two separate cards would solve my problem and PCI-Express will allow that (I know I could go get a PCI card but again, PCI saturation with other devices could result).

That is my $0.02

 

[MorganX]

Re: Missing the point

Originally posted by ZinK


In the case of PCI-Express, we ask the following questions:
who needs that much bandwidth when we do not saturate the current standard?
what manufactures will produce cards for PCI-Express?
what price premium will we pay for this new technology?

Anyone who uses video and 3D on a PC. When you have real-time Toy Story quality on a PC, then you have enough CPU and GPU power. If you've seen some Longhorn advanced demos, it will need this power throughout the OS and not just for eye candy. I would imagine the same for OS X. With Window effects, 3D and video on the desktop all going at the same time, I think PCI-E will be a standard requirement in no time.

ATI, NVIDIA, Intel. Does anyone else really matter?

Since it will be the de facto standard on new PCs in 2ndH of 2004 with the Grantsdale family of chipsets, the premium should be in line with purchasing the current top-of-the-line GPU now. Of course the Grantsdale-G chipset has a PCI Express version of Inel's cheesy 3D architecture.