8x pci-e enough bandwidth for x800GTO2?

[<barfly>]

Because of space requirements, I might need to move down my video card to the lower slot on my lanparty ultra-d mobo. I am aware that withough the sli mod, the lower slot can only run at a max 8x. Is this going to be enough for my card? If not, and i do the sli mod, can i run a single video card in the lower slot at 16x? Thanks

[JigPu]

My guess is that you'd be fine. No card (unless I'm sorely mistaken) uses AGP 8x bandwidth, and since PCI-E has more bandwidth than AGP you shouldn't see any performance drop.

The one thing I'd be concerned about is possible driver problems. I haven't messed with PCI-E yet, but it's possible that ATI or your Mobo won't like having the primary video in the non-16x slot. The only way would be know would be to try I guess...

Jigpu

[IWasHungry]

8x speed should be fine. Just make sure you move the jumpers on the motherboard to SLI, or it will run at 2x instead of 8x. Now THAT would bottleneck.

Also note that using 8x instead of 16x will yield maybe a few hundred less points on 3DMark. In essence, using 8x will be a slight bottleneck, but not too much to fret about.

[Quailane]

Also note that using 8x instead of 16x will yield maybe a few hundred less points on 3DMark. In essence, using 8x will be a slight bottleneck, but not too much to fret about.

Not really. The X850XT on agp and PCI-E x16 scores the same. x8 PCI-E has the total bandwidth of AGP going in each direction. In no way will x8 slow you down.

[IWasHungry]

I dunno, I've done benchmarks of the same card on 8x PCIe and 16x PCIe (X850XT-PE), and it's just something I noticed.

[JigPu]

IWasHungry, could you post up those benchmarks? I've always been interested in just how much difference the port bandwidth actually makes :) Also, if possible could you benchmark at lower speeds as well (1x and 4x)?

JigPu

[HousERaT]

I've done tests on both slots and I've been running my cards in the second slot for over a year now. No noticable difference between the two slots.

[IWasHungry]

Yeah sure. I just got my new motherboard today, so I have to re-update everything. I should have benchies either tonight or tommorrow. :)

[Enablingwolf]

I am interested in the results also. :D

[Dan0512]

What about PCI-E x4? I've heard some guys that run SLI on A8N-E boards without the bridge, dunno if both cards then run at x4...still nothing for me since I have Ati.

Dan

[IWasHungry]

Results (Note that this is a new motherboard, so I still have to optimize CPU and RAM clocks. In other words, scores might be a little lower than usual):

16x in top slot
http://img.photobucket.com/albums/v260/iwashungry/03-16x.jpg
http://img.photobucket.com/albums/v260/iwashungry/05-16x.jpg

8x in bottom slot
http://img.photobucket.com/albums/v260/iwashungry/03-8x.jpg
http://img.photobucket.com/albums/v260/iwashungry/05-8x.jpg

2x in bottom slot
http://img.photobucket.com/albums/v260/iwashungry/03-2x.jpg
http://img.photobucket.com/albums/v260/iwashungry/05-2x.jpg

Not sure what to make of these results. I expected 2x scores to be a lot less than the other two, but they're only slightly lower.
And then the 8x scores <1% lower than the 16x scores. Why is there any difference at all?

[JigPu]

Interesting results to say the least! :) A 6% drop is a lot less than I was expecting from the 2x slot.

JigP

[ViperJohn]

Because of space requirements, I might need to move down my video card to the lower slot on my lanparty ultra-d mobo. I am aware that withough the sli mod, the lower slot can only run at a max 8x. Is this going to be enough for my card? If not, and i do the sli mod, can i run a single video card in the lower slot at 16x? Thanks

Yes

Viper