PCI-X vs AGP

[MinusZero]

I have read all around the web of the pros and cons about this two piece of hardware.

My understanding is that PCI runs at a max of 66Mhz. According to Toms Hartdware, the data transfer is ~200Mhz/sec.

On the other hand, the AGP port is accelerated as opposed to the PCI. The data transfer coefficient is 266Mhz times 8 = 2.13Ghz/sec. No PCI express cannot achieve this speed. I have read of initial speed of 2.5Ghz (and not sustained) for PCI-X.Also, AGP slot allows the use of RAM memory as apposed to the PCI-X.

Thanks.

 

[cubby1223]

PCI-X is not PCI Express. That should be your starting point to this research.

 

[cubby1223]

Here's a reference board that has both:
http://www.tyan.com/products/html/thunderk8we.html

 

[mwmorph]

pci runs at 33mhz at 3.3v signal voltage. Can shift 133mb/s 32bit
pci 66mhz runs at 66mhz 32bit
pci-x(pci-extended) runs at 133mhz. bakcward compatible. 64bit
agp runs at 66mhz x 4 or 8 most commonly at 1.5v sig voltage(agp 1x and 2x run at 3.3 signal voltage) can shift 2.1gb/s on agp8x
pci-e is completely different and uses a independent but it runs at some crazzy mhz and offers 4gb/s transfer per second

in truth modern games dont press even 2.1gb/s but it's good to have pci-e because agp is a dying format.

 

[theMan]

pci-e doesnt offer any performance over agp -- yet. but, all the new cards, and mobos are coming out in PCI-E, so unless you want to get stuck not being able to upgrade, its a good idea to get PCI-e.

 

[xtknight]

PCIe offers tons of performance benefits over AGP. There have just not been video cards released to take advantage of it yet, but the X1900s are probably getting close if they haven't already saturated AGP 8x. There are other things than video cards, too. PCIe x16 might be a revolution for capture cards.

 

[Sonikku]

Since PCI Express debuted it has been far more about marketing and getting people to upgrade sooner rather then later as opposed to offering some actual improvement in performance versus agp.

 

[Matt2]

PCI-E is the future, like it or not. I would advise anyone building a system NOT to get AGP and save themselves a lot of headaches.

 

[MinusZero]

Folks:

We have to understand that WE R the ones who dictates the market and not the suppliers. If we do not support PCI Express and the harware stays on the shelves, they cannot impose us nothing.

I still have my doubts about this new technology. Anyway, I do not plan to put together any new system 'til I can get a RAM memory which speed is >1000Ghz. I'll stay with AGP for a long time.

 

[MinusZero]

I see and EVGA Video Card on your system, Matt. Good 4 U. It have been shown to have the highest speeds. I have in my current system and 5200 256MG video card and runs Q4 nicely.
I'll tell U a secret, thou:

In order to file a warraty claim to EVGA, you have to pay.

Have a good one.

 

[Ayah]

Originally posted by: MinusZero
I see and EVGA Video Card on your system, Matt. Good 4 U. It have been shown to have the highest speeds. I have in my current system and 5200 256MG video card and runs Q4 nicely.
I'll tell U a secret, thou:

In order to file a warraty claim to EVGA, you have to pay.

Have a good one.

That's not definitive. For one, most ViperJohn modded cards with adequate cooling can hit speeds which make eVGAs seem like snails.

And of course we have our regular volt modders who push the thermal limits of these poor video cards. Stock speeds are nothing in comparison.

Considering that the PCI shares the overal bandwidth through everything on the bus, it's a huge limitation to our current technology.

Considering that you can only have one AGP slot, SLI and Crossfire would be non-existant.

 

[zephyrprime]

Originally posted by: xtknight
PCIe offers tons of performance benefits over AGP. There have just not been video cards released to take advantage of it yet, but the X1900s are probably getting close if they haven't already saturated AGP 8x. There are other things than video cards, too. PCIe x16 might be a revolution for capture cards.

Video cards aren't even close to using the bandwidth of AGP. All the tests people ran with AGP where they tested at 2x and 8x showed only a ~2% performance boost. The fact of the matter is, video cards actually don't transfer a whole lot of data across the bus. They don't need to. They have lots of onboard memory to cache textures. What's more, with the advent of geometry instancing, the bus traffic will be lowered. However, PCIe will probably be a boon to video capture as you say. It's also great for RAID.

 

[Steve]

Originally posted by: MinusZero
Folks:

We have to understand that WE R the ones who dictates the market and not the suppliers. If we do not support PCI Express and the harware stays on the shelves, they cannot impose us nothing.

I still have my doubts about this new technology. Anyway, I do not plan to put together any new system 'til I can get a RAM memory which speed is >1000Ghz. I'll stay with AGP for a long time.

Unfortunately WE are a small fraction of the market. The market will use PCI-E because it is being used in the biggest cuts of the market: Dell, HP/Compaq, etc...

 

[cpacini]

Originally posted by: MinusZero
Folks:

We have to understand that WE R the ones who dictates the market and not the suppliers. If we do not support PCI Express and the harware stays on the shelves, they cannot impose us nothing.

I still have my doubts about this new technology. Anyway, I do not plan to put together any new system 'til I can get a RAM memory which speed is >1000Ghz. I'll stay with AGP for a long time.

You're free to buy what you want, but there is absolutly no reason to build a new AGP based system. PCIe is superior technology and will replace AGP. Also, PCIe cards are cheaper than thier AGP counterparts, and highend AGP cards are non-existant.

 

[Sc4freak]

I agree, you'd have to be a fool to buy AGP if you're building a new rig.

The decision gets hard if you have an existing AGP rig and are looking to upgrade your video card...

 

[GhostDoggy]

Try running 1920x1080 progressive at 120Hz and see if the AGP can pass that kind of bandwidth. Oh, wait, it can't because the PCI bridge for which the MPEG decompression must come across can't handle it. Tough break, AGP. It all depends on how one needs their video. If one is generating the images as in a video game its an AGP-satisfactory world, but if you are using it to deliver high-definition video at high refresh then the convention PCI bridge is incapable of delivering the bitrates to the video card in the first place.

PCI express is about the backplane bandwidth. AGP is dependent on PCI for decompressed video being delivered to it.

 

[mindless1]

Originally posted by: GhostDoggy
Try running 1920x1080 progressive at 120Hz and see if the AGP can pass that kind of bandwidth. Oh, wait, it can't because the PCI bridge for which the MPEG decompression must come across can't handle it. Tough break, AGP. It all depends on how one needs their video. If one is generating the images as in a video game its an AGP-satisfactory world, but if you are using it to deliver high-definition video at high refresh then the convention PCI bridge is incapable of delivering the bitrates to the video card in the first place.

PCI express is about the backplane bandwidth. AGP is dependent on PCI for decompressed video being delivered to it.

You have no idea what you're talking about. 120Hz has NOTHING to do with the AGP bus. There is no PCI bridge to AGP, that's the WHOLE POINT of AGP.

You know nada about MPEG too. Give up while you're only one post down.

 

[mwmorph]

Originally posted by: mindless1

Originally posted by: GhostDoggy
Try running 1920x1080 progressive at 120Hz and see if the AGP can pass that kind of bandwidth. Oh, wait, it can't because the PCI bridge for which the MPEG decompression must come across can't handle it. Tough break, AGP. It all depends on how one needs their video. If one is generating the images as in a video game its an AGP-satisfactory world, but if you are using it to deliver high-definition video at high refresh then the convention PCI bridge is incapable of delivering the bitrates to the video card in the first place.

PCI express is about the backplane bandwidth. AGP is dependent on PCI for decompressed video being delivered to it.

You have no idea what you're talking about. 120Hz has NOTHING to do with the AGP bus. There is no PCI bridge to AGP, that's the WHOLE POINT of AGP.

You know nada about MPEG too. Give up while you're only one post down.

I have to agree. wtf are you talking about ghostdoggy? 1920x1080 120hz no possible means the ramdac is not fast enough. pci to agp bridge? wtf? If you need more than 2.1gb/s for your uncompressed video, i'd be more worried about the hdd performance than your video card perfromance.

 

[GhostDoggy]

Originally posted by: mindless1

Originally posted by: GhostDoggy
Try running 1920x1080 progressive at 120Hz and see if the AGP can pass that kind of bandwidth. Oh, wait, it can't because the PCI bridge for which the MPEG decompression must come across can't handle it. Tough break, AGP. It all depends on how one needs their video. If one is generating the images as in a video game its an AGP-satisfactory world, but if you are using it to deliver high-definition video at high refresh then the convention PCI bridge is incapable of delivering the bitrates to the video card in the first place.

PCI express is about the backplane bandwidth. AGP is dependent on PCI for decompressed video being delivered to it.

You have no idea what you're talking about. 120Hz has NOTHING to do with the AGP bus. There is no PCI bridge to AGP, that's the WHOLE POINT of AGP.

You know nada about MPEG too. Give up while you're only one post down.

No need to insult, but if it makes you feel good to flame then so be it. I never said the bus had anything to do with the refresh rate. I mentioned it was dependent upon what you were looking to use it for, such as high-definition video decompression for the purpose of running 1920x1080P at a high refresh rate.

 

[GhostDoggy]

Originally posted by: mwmorph

Originally posted by: mindless1

Originally posted by: GhostDoggy
Try running 1920x1080 progressive at 120Hz and see if the AGP can pass that kind of bandwidth. Oh, wait, it can't because the PCI bridge for which the MPEG decompression must come across can't handle it. Tough break, AGP. It all depends on how one needs their video. If one is generating the images as in a video game its an AGP-satisfactory world, but if you are using it to deliver high-definition video at high refresh then the convention PCI bridge is incapable of delivering the bitrates to the video card in the first place.

PCI express is about the backplane bandwidth. AGP is dependent on PCI for decompressed video being delivered to it.

You have no idea what you're talking about. 120Hz has NOTHING to do with the AGP bus. There is no PCI bridge to AGP, that's the WHOLE POINT of AGP.

You know nada about MPEG too. Give up while you're only one post down.

I have to agree. wtf are you talking about ghostdoggy? 1920x1080 120hz no possible means the ramdac is not fast enough. pci to agp bridge? wtf? If you need more than 2.1gb/s for your uncompressed video, i'd be more worried about the hdd performance than your video card perfromance.

Wow, this is a startling condition. If the video card is not capable of twice the refresh rate of am full HD stream then what good is it? BTW, the HDD typically stores HD video in compressed form. Broadcast 1080i is only 19.1Mbps, and even D-Theater D-VHS maximum is 28.2Mbps in compressed form. But I was more concerned about when the CPU and decompressor turns that into >>1.5 Gbps of uncompressed video stream.

Hey, its a Sunday morning and maybe my brain isn't awake yet.

 

[Steve]

Why the fnck would you need 120Hz?

 

[Fox5]

Originally posted by: mwmorph
pci runs at 33mhz at 3.3v signal voltage. Can shift 133mb/s 32bit
pci 66mhz runs at 66mhz 32bit
pci-x(pci-extended) runs at 133mhz. bakcward compatible. 64bit
agp runs at 66mhz x 4 or 8 most commonly at 1.5v sig voltage(agp 1x and 2x run at 3.3 signal voltage) can shift 2.1gb/s on agp8x
pci-e is completely different and uses a independent but it runs at some crazzy mhz and offers 4gb/s transfer per second

in truth modern games dont press even 2.1gb/s but it's good to have pci-e because agp is a dying format.

I'd wager that modern games don't press even 2.1GB/s because the only thing modern games use the bus for right now is agp texturing (well, that and some geometry data) which is limited by the system ram, which is being eaten up by the cpu anyway. Plus AGP/PCi-Express texturing would be way slower than on board vram anyway, and a split second drop to 10 fps or 13 fps isn't a big difference.
I believe DirectX 10 introduces the ability for the cpu to write directly to vram, and that could make use of the high pci-express bandwidth.

 

[sandorski]

AGP is dead/dying, PCI-e is the future. It's aleady too late to try and stop it.

 

[xtknight]

Edit: Never mind. Worthless argument anyway.

The point is, PCIe x16 still provides more theoretical bandwidth, and this is a good thing, not a bad thing. Video cards aren't the only devices in a computer. Some people just can't let go of AGP I guess.