How much performance increase is there over PCI-e 2.0 from PCI 1.0 ?

Are you comparing PCIe v2 (8GB/s) to PCIe v1 (4GB/s) or the old PCI (532MB/s)?

PCIe v2 to PCIe v1 although both are x16, you mention that one is 8 GB and the other is 4 GB. What is the real difference in speed?

Hi Siberian

Its the transfer rate per link (or lane) that changed within the standard.
v1 had 250MB/s
v2 doubled that to 500MB/s
v2.1 reduced the overhead due to management/control, giving more room for data.
v3 will double the rate again to 1000MB/s per link

This is just the squirting of data to and from the graphics card, its the construction of the cards that make the real differences in speed.

Oh I see. It matters but not significantly :) As you mention it's the construction of the card :) If you have a good card or even a power horse card on PCI v1 you can continue to benefit.

In theory, yes.
PCIe v3 is even backwards compatible all the way to v1.

But as you know, as soon as something is made faster or bigger in a computer the other components soon use up the new capacity.

PCIe v1 will certainly hold back the latest PCIe graphics cards

In my own field (3D visualisation) were just on the verge of rendering with the graphics cards instead of the CPU.
I can already see the 16GB/s of PCIe v3 becoming a bottleneck!

It is understandable that it will to some degree hold the graphics card back, but as long as the graphics card is still capable of using most of it's power that is good :)

How are you using the graphics card to render ?