At which point was PCI Express 2.0 beneficial for single card setups?

[TreadwellLikesGrizzlies]

I have a motherboard with PCI Express 1.0 x16 (1.1a apparently). I want to upgrade my video card and am wondering at which point cards used by themselves (no SLI or Crossfire) without overclock actually took advantage of PCI Express 2.0??

I read that the Geforce 9800GTX 512MB PCI-E 2.0 does not take advantage of PCI Express 2.0 when run alone so I could just as well get this card and it will run as per its normal specs even with my PCI Express 1.0 x16 slot (apparently 1.1a) ...

I don't understand this because on Wikipedia it says that with 2.0 you get a standard bus bandwidth of 0.5GByte/s and with an x32 connector you get up for 16 GB/s for both videocards. So I will assume that with only one, you can actually get up to 32 GB/s.

But then according to Techarp, the Geforce 9800GTX 512MB PCI-E 2.0 has a memory bandwidth of 70.40 GB/s...

But then why would they make a card that fast if the PCI Express 2.0 technology only goes up to 32 GB/s... so I guess it can handle more...

The bottom line is if I am shopping for and then using a single video card, and not overclocking, and have sufficient wattage in my power supply, at which point would a "PCI Express 2.0" being run on my motherboard (Capable of PCI Express 1.0 x16 ... 1.1a apparently) actually start to perform below the stock specs as seen on a site like Techarp (eg- According to Techarp, the GeForce 9800GTX 512MB PCI-E 2.0 has a memory bandwidth of 70.40 GB/s...)

Maybe some clarification on how much memory bandwith (in GB/s) the PCI Express 1.0 x16 (1.1 apparently) can handle assuming a single card?? That should help me when I scan the lists on Techarp... Or perhaps there are other factors which come into play.

Thanks for reading this and thanks for any help!!

 

[error8]

You are mixing video memory bandwidth with the actual pci express bandwidth. Videocard's memory bandwidth means how fast can the GPU exchange data with Vram and it has nothing to do with actual pci express bandwidth.

You can search through these threads and find out that other people have asked the same question before. As for 9800GTX, there is no performance hit whatsoever, on a PCI express 1.1 slot.

 

[apoppin]

At which point was PCI Express 2.0 beneficial for single card setups?

Beginning with 4870 and especially noticeable with GTX280

 

[vj8usa]

http://alienbabeltech.com/main/?p=2249&all=1

 

[magreen]

Really apoppin? I was under the impression that no single card on the market could max out the pci-e 1.0 16x bandwidth.

 

[apoppin]

Originally posted by: magreen
Really apoppin? I was under the impression that no single card on the market could max out the pci-e 1.0 16x bandwidth.

i did a little research on this

Look at the link posted just before you commented
- it covers it, i believe

 

[error8]

I would say that only dual GPUs cards are seeing some performance hit on a pci express 1.0 slot. The GTX 280 difference in Lost Planet, seems just too big to be true. I mean how can PCI express 2.0 give the GTX 280 double the frame rates that it had over the PCI express 1.0 slot, when 4870x2 sees no improvement at all, for example. It had to be driver related somehow.

 

[apoppin]

Lost Planet was the only benchmark that showed extreme differences. If you look carefully, the *trend* is for GTX280 to be generally faster on the 2.0 PCIe spec.

No it is not a deal breaker, imo - but it is *beneficial* to upgrade from a 1.1 or 1.0 PCIe MB - especially if you have a fast GPU; clearly for faster cards - or multi-GPU it is important

 

[TreadwellLikesGrizzlies]

Thanks everyone!

 

[imported_Scoop]

Originally posted by: apoppin
Lost Planet was the only benchmark that showed extreme differences. If you look carefully, the *trend* is for GTX280 to be generally faster on the 2.0 PCIe spec.

No it is not a deal breaker, imo - but it is *beneficial* to upgrade from a 1.1 or 1.0 PCIe MB - especially if you have a fast GPU; clearly for faster cards - or multi-GPU it is important

The *trend* is that there's not even a 2 fps difference in the average frame rate which is about the variance from a better motherboard. And in some cases the average frame rates actually drop so it might have a negative effect!!

And what were those guys smoking? "4870-X2 and even 4870 has a nice increase on a X48 motherboard over P35." Seriously. 4870X2 got 0.4 fps better average framerate in the lost planet - cave test. That's a nice increase? Laughing my ass off.

X48 boards generally perform better than P35 boards. That's a point to think about when choosing a board.

 

[error8]

Originally posted by: Scoop

Originally posted by: apoppin
Lost Planet was the only benchmark that showed extreme differences. If you look carefully, the *trend* is for GTX280 to be generally faster on the 2.0 PCIe spec.

No it is not a deal breaker, imo - but it is *beneficial* to upgrade from a 1.1 or 1.0 PCIe MB - especially if you have a fast GPU; clearly for faster cards - or multi-GPU it is important

The *trend* is that there's not even a 2 fps difference in the average frame rate which is about the variance from a better motherboard. And in some cases the average frame rates actually drop so it might have a negative effect!!

And what were those guys smoking? "4870-X2 and even 4870 has a nice increase on a X48 motherboard over P35." Seriously. 4870X2 got 0.4 fps better average framerate in the lost planet - cave test. That's a nice increase? Laughing my ass off.

X48 boards generally perform better than P35 boards. That's a point to think about when choosing a board.

"Those guys" is apoppin.

I would say that those 2 fps might also be included in the error's margin of the benchmarks. If you rerun the tests a coupe of times, there will probably be situations where the difference is smaller, or even 0.

 

[apoppin]

feel free to stick with your p35 MBs .. as i said, it is no deal breaker - not yet for single GPU

i haven't tested GTX285 - but we know for a fact that multi-GPU is constrained by PCIe 1.1/1.0 .. and it predicts the next generation of GPU

 

[error8]

Next generation cards will surely need more then the bandwidth of PCI express 1.X, I think there is no doubt about it.

 

[Blurry]

I thought AGP 8X was enough?

 

[MrK6]

Right now no card needs PCIe 2.0 - the differences are insignificant. In the link above, even the 4870X2 doesn't really see any improvement from PCIe 2.0 (two GPUs running through only one slot remember). A lot of the differences you see there are probably more driver-dependent than actual limitations of the PCIe 1.x bus.

 

[happy medium]

Originally posted by: Blurry
I thought AGP 8X was enough?

Na, agp 8x is starting to bottleneck my 3870 agp card.

 

[apoppin]

Originally posted by: MrK6
Right now no card needs PCIe 2.0 - the differences are insignificant. In the link above, even the 4870X2 doesn't really see any improvement from PCIe 2.0 (two GPUs running through only one slot remember). A lot of the differences you see there are probably more driver-dependent than actual limitations of the PCIe 1.x bus.

agreed .. but the driver dependent differences tend to occur mostly in favor of higher bandwidth

the OP is asking if it is "beneficial"
- for GTX280, incrementally - for GTX285, logic says PCIe 2.0 is even more beneficial than using PCIe 1.0/1.1

 

[evolucion8]

Originally posted by: happy medium

Originally posted by: Blurry
I thought AGP 8X was enough?

Na, agp 8x is starting to bottleneck my 3870 agp card.

never knew that the hd3870 came to agp. i thought that only the hd3850 came to agp which barely bottlenecks the agp bus. most agp systems are heavily cpu bound with such card.