PCIe gen 2 vs gen 3

oomwoc

Honorable
Jun 10, 2012
6
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10,510
I know that PCIe 3 theoretically doubles the bandwidth, but what are the real world differences between the two? For example, if I install the HD 7850, will there be a noticeable difference in performance in games and/or video? If so, should I buy an Ivy Bridge instead of the i2500k just to get PCIe 3?

Thanks!
 
Solution
Realistically there's very little difference

There's a slight difference between a high end graphics card running at 8x 3.0 and 8x 2.0 but no noticeable difference between a card running at 16x 3.0 and 16x 2.0. 8x 3.0 is understandably on par with 16x 2.0

The two real advantages of 3rd generation PCIe are lower latencies (channels are interleaved) so cards can start working quicker, and reduced data overhead due to a change from 8b/10b encoding used on gen 2 to 128b/130b encoding used on gen 3.
Realistically there's very little difference

There's a slight difference between a high end graphics card running at 8x 3.0 and 8x 2.0 but no noticeable difference between a card running at 16x 3.0 and 16x 2.0. 8x 3.0 is understandably on par with 16x 2.0

The two real advantages of 3rd generation PCIe are lower latencies (channels are interleaved) so cards can start working quicker, and reduced data overhead due to a change from 8b/10b encoding used on gen 2 to 128b/130b encoding used on gen 3.
 
Solution