Why is PCI Express being pushed so hard?

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dev0lution

Senior member
Dec 23, 2004
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For all of the above reasons plus the economics ($$) factor.

A slow transition requires manufacturers to design for PCI-E and AGP which isn't cost effective. Hence, they push (read - force) you to adopt it by putting it on (most) all the new products. For a generation or two they'll release AGP versions a la the X850, but a faster transition saves them from a bloated product line with two versions of every card.

Everyone's studied at Micro$oft university. If they don't cut you off from their old tech, how can they get you to buy the new? ;)
 

imported_brad

Member
Jan 6, 2005
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i would say in a nutshell...it is being pushed because in the near future its capabilites will be greater than agp. Its only been around for a short while and the two are comprable. Before long, it will not be comprable.
 

KamiXkaze

Member
Nov 19, 2004
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I guess it is my turn now.

1.AGP for now is here to stay. yes it is true that there are some systems(servers, high end workstation) that use pci-e , but as for the average user which is the majority of computer buyers pci-e is not necessary.
2.Technology changes all the time ISA,EISA,VLbus,and pci are all one trick pony that last for only x amount of years.
3.companies will always make money off of new tech only because they have a fuduciary reponsebility to there shareholder.



KxK
 

DanDaMan315

Golden Member
Oct 25, 2004
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Will we be seeing PCI-E sound cards anytime soon? Although I don't see a need, my Audigy 2 ZS buts out perfect sound. The human ear can't even really distiguish higher sound quality anyways, unless your an audiophile.

What about PCI-E lan cards? Thats an interesting idea, even though integrated lan is always going to be faster.
 

elecrzy

Member
Sep 30, 2004
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actually, if you wait a bit, VIA will be coming out with a chipset that will include PCIe(8x or 16x?) and also AGP. i think its their K8T89x series.
 

elecrzy

Member
Sep 30, 2004
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the new VIA chipset will allow people to use their AGP card and upgrade to PCIe later. One cool thing about this chipset is that it will allow AGP and PCIe video cards to run at the same time, allowing u to have dual monitors with independent video overlays on each and among other stuff...oh and u can use up to 4 monitors with this setup.
 

elecrzy

Member
Sep 30, 2004
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SLI combines the processing power of two video cards. VIA hasn't implemented their version yet.
 

rcrmb

Member
Feb 17, 2004
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Originally posted by: elecrzy
the new VIA chipset will allow people to use their AGP card and upgrade to PCIe later. One cool thing about this chipset is that it will allow AGP and PCIe video cards to run at the same time, allowing u to have dual monitors with independent video overlays on each and among other stuff...oh and u can use up to 4 monitors with this setup.

Where did you catch wind of this?
 

Concillian

Diamond Member
May 26, 2004
3,751
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Originally posted by: DanDaMan315


Please help me understand what the need for PCI-E is.


The need for PCI-e has nothing to do with AGP vs. PCI-e for video cards. The transition has everything to do with the transition from PCI to PCI-e.

Unfortunately it's prohibitavely expensive for AGP to co-exist with PCI-e because of the logic needed on the chipset. So the side effect is pushing out AGP.

PCI has been running out of bandwidth for a while. Hard drives, network cards, sound cards, etc... all share the 133 MB/sec PCI bus. The right application would make it nearly impossible NOT to saturate the PCI bus unless you went to a server board for big $$$ where they use PCI-X slots (64 bit and 66MHz).

PCI-e will allow for additional functionality on expansion cards, especially multimedia and networking that were impossible with the PCI architecture.

AGP gets stuck in the middle. It is adequate for graphics cards, but PCI-e x16 for graphics is at least as good with the logic already dedicated to chipset real-estate for PCI-e x1 and x4 slots.

The quick transition here as opposed to the relatively slow transition from PCI --> AGP graphics cards is due to the inability for PCI-e and AGP to co-exist on the same board without significant manufacturing costs. Also, board manufacturers (both motherboard and graphics board) currently have to have AGP and PCI-e versions of all their products. This either inflates prices or cuts into profits because of the associated manufacturing inefficiency.

I was expecting a quick transition, but the transition has even been quicker than I expected. You are already seeing PCI-e video cards having a better selection at better prices than AGP cards. Motherboard prices are still high, but video card prices for PCI-e are good. If you're building a new system, it pretty much already makes sense to go PCI-e.

The other force pushing PCI-e is Intel. Intel is pushing it to get BTX out. AMD's integrated memory controller requires motherboard layouts that are not very easy to bring into BTX compliance. If Intel can push out the new case standard, and people begin switching over to it, it becomes a 'hook' for Intel. Again AGP gets caught in the middle. It's not the primary reason for pushing out new technology, but more of an innocent bystander victim.

The forces behind the AGP-->PCI-e transition are economic, and unlike ISA --> PCI, where there was little reason not to throw on an ISA slot or two, the transition will be as quick as possible.
 

DanDaMan315

Golden Member
Oct 25, 2004
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BTX is going NOWHERE, the motherboard and case manufacturers are happy with the way they have been making things. Intel needs to make a CPU that isn't a flaming hot power hog, thats the issue, AMD is having no problems.

Yea it looks like by this fall, when I planned to upgrade my video card, I will just have to go buy a new motherboard and processor as well. The AGP availability and pricing is getting really bad really fast.
 

RaiderJ

Diamond Member
Apr 29, 2001
7,582
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Originally posted by: CQuinn
1. PCI-Express is not just a replacement for AGP, it is a upgrade to the whole PCI concept.

We are already seeing and reaching the limits of PCI bus speeds. AGP was invented in the first place
to accomodate the greater bandwidth requirements of video over the rest of the system. So the
idea that we would eventually need to increase PCI performance for the rest of the system has always
been there.

2. AGP will be an 8 year old technology this year.

And it took a couple of those years before it was considered "mature" enough to replace PCI across the board.
If PCI-E spreads at the same rate, it will be 2007 (the 10 year mark for AGP) before PCI-E is widespread
enough to become the de facto standard. If the industry is not on a big push to start implementing PCI-E
now, then we could end up with the same situation as the "local bus wars" of the early 90's (with EISA, Microchannel,
VESA and PCI all competing to replace the aging ISA slot).

3. The limits for technology are already being pushed on the high end.

There are a few technologies that come close to pushing the limits for speed of the PCI bus.
SATA, Ultra320 SCSI (and soon SAS), Firewire 800, & Gigabit Ethernet for example. It has come to the point
where the bus itself can become a bottleneck for the rest of the system, especially on the high end of computer
server/workstation usage. It is more cost-effective to design PCI-E in for all systems, than to keep it at a
premium for only the systems that may push the technology today.

4. AGP does not allow to efficient two way data transfer.

AGP was originally designed to send massive amounts of data from the system to the video card, but not the other way around.

GPUs have become sophisticated enough that there is serious consideration of ways to offload some instructions from the
CPU to this other engine, for many types of mathmatically intensive uses. For this, AGP becomes a serious bottleneck, where
PCI-E was designed to take this need into account.

5. PCI-E is a solution for signalling issues with trying to create faster connection speeds.

PCI-E, as a serial connection with less wires used to facilitate data transfer, also can compensate better with the variances
between FSB, CPU, Memory and devices timing issues that often affect parallel PCI connections, and plague overclockers.

FishTankX, if I'm not mistaken, burst transfer rates and command signalling do meet or exceed the current ATA-100 spec.
The transfer of data is only part (an important part) of what information needs to be sent from the device to the rest
of the system. The idea of always keeping the signal speed higher than the data rate is to allow room for processing
overhead that is needed to support things like S.M.A.R.T, error-correction, NCQ/TCQ, RAID, and other useful features
of such devices.

:thumbsup:
 

Cawchy87

Diamond Member
Mar 8, 2004
5,104
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The only current use I have been able to find is for highspeed video capture of photon experiments.