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16x vs 8x PCI-E bandwith

post #1 of 13
Thread Starter 
How much of a difference in performance does 16x have over 8x ?
I am wondering because I have the Asus M4A89GTD PRO/USB3 AM3 motherboard and it uses the VGA switch card in PCI-E 1 to make the PCI-E 2 slot go 16x, It doesn't work the other way around and the first slot is only 8x.
I don't really like having my GPU in the second slot but if it makes a big difference in performance it really doesn't matter.
post #2 of 13
Would depend on what your graphics card is.

What are you using?
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Samsung M.2 SM951 Samsung 850 Pro Bitfenix Maximus Impact full block 2x XSPC 240mm Slim Radiators 
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post #3 of 13
I believe it's around 1-3% overall, and that's at its highest point. In short, you probably wouldn't see much if any difference at all in most cases.
post #4 of 13
Thread Starter 
Im using the HD 5850 at the moment. Okay thats not that much, kind of dumb how the first slot is only 8x frown.gif

Also where can I put a forum signature, I want to put my system specs in there.
post #5 of 13
Click your username top right of this page > scroll to the bottom of the next page and you should see "add rig"
Edited by Hillskill - 1/29/12 at 11:39am
post #6 of 13
Yeah, the answer is not much.

That's an annoying design.
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post #7 of 13
Most likely 0% unless you are using very high-end cards and playing at a very high res
post #8 of 13
I did benchmarks a while ago with 16x compared to 8x on my 6950. I think I lost roughly 50pts in 3dMark11 from switching to 8x from 16x. So the different is pretty much non-existent in anything other than benchmarks.
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post #9 of 13
Thread Starter 
well right now ive got the 5850 but in the future i am looking towards the 7970.....BUT i will most likley be saving and waiting to see what intel has to offer in april so id probably just get a fairly high end board anyways. no big deal im just kind of OCD about where the card is smile.gif
post #10 of 13
Personally I would always go with the fastest single GPU I can afford before putting in two mid range cards for Xfire or SLI. What system do you have? P55 like mine? i was originally disappointed I would only ever have 16x 8x but I just threw a 580 in there and enjoy games. Aint no thang!
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