Going from PCI-Express 1.0a to 2.0
To get right to the point, upgrading from PCI-Express 1.x to 2.0 is not worthwhile for now. The current crop of graphics cards just doesn’t tax the PCI-Express bus enough for a difference to be visible. All test cards across the board showed a minor performance boost of 1 to 2 percent, with the HD2900 XT reaching better results despite the fact that it doesn’t have a 2.0 interface.
This improvement may be caused by the newer chipset or the higher memory speed. Also, a difference of 1 to 3 percent is also slim enough to be considered within the margin of error. It remains to be seen what the situation looks like when newer graphics cards such as the Geforce 9 or the Radeon 4xx0 begin transferring larger amounts of data over the bus. At any rate, the P35 and 975 chipsets are easily sufficient for the current generation of cards.
all very nice but like every article before this one, you do not mention the causes of bandwidth uses. so, like all your previous article's here on toms it is absolutely useless for anything other than saying"ooh, look at the fancy graph, aint they pretty" because apart from graphs the article has damn all to do with testing anything.
I found it useful, I now know I can save money by not upgrading just yet. That's more beer money in my pocket, that has to be useful.
What I have, serves my needs. Besides, these articles tend to be aimed at the games-playing mentally-preadolescent set, so they can't get too in-depth.
Erm.. am I missing something?
If one card increases by about 7% going from x8 to x16, then each card in a crossfire setup would increase by about 7% going from 2x8 to 2x16. Therefore the overall performance would improve by 7%. Why would you expect it to increase by more ("twice as much, which we would have expected based on the single card results")? If anything it should increase by less, due to increased loads on the chipset/system memory/processor etc.