There has been a lot of misunderstanding regarding this since the release of the platform and Sandy Bridge-E CPUs. This is mainly due to wording.
SB-E CPUs are PCIe 3.0 "capable" but not "certified". This means that they theoretically support PCIe 3.0 but they have not actually been tested and certified for it. The reality of things is that PCIe cards were not out yet so there was nothing to certify against.
Then nVidia's 6xx series came out and people found the hard way that team green is disabling 3.0 mode with their driver installers for this platform.
There was a lot of fuss about it and certain registry changes began to circulate, that would enable 3.0 mode on these cards. nVidia then went ahead with this public statement and the release of a tool that
would basically apply and revert these registry changes directly so GEN3 support could be manually enabled on X79: nVidia Statement & Tool
My own personal testing, while profiling code, showed several driver stalls/timeouts when GEN3 support was enabled. The driver could actually recover from (in most cases) BUT it did actually slow the performance down, as was expected. I went ahead and tested 8x SB-E CPU samples that I had access to and the results where similar. The difference was in severity of the issue only. Some samples produced stop errors, others seemed fine when in fact they were not.
The result of this was me acquiring a personal habit of suggesting, to everyone asking for advice, to not enable GEN3 support on this platform at all. There are no benefits from GEN3 anyhow since the bandwidth of GEN2 is still not getting saturated by the top end cards.
Now that this background info is out of the way, I can get to the point that the newly released Ivy Bridge-E CPUs for the X79 platform solve these issues. X79 platform owners can now utilize PCIe GEN3 without any issues whatsoever!
Of course the benefits of doing so are still non-existent. Perhaps GEN3 RAID SAS/SATA HBAs can benefit from it but when it comes to video cards, you will not see any performance increase that is outside the margin of error unless you are utilizing huge "Surround" type resolutions. 4K monitor booths anyone?
SB-E CPUs are PCIe 3.0 "capable" but not "certified". This means that they theoretically support PCIe 3.0 but they have not actually been tested and certified for it. The reality of things is that PCIe cards were not out yet so there was nothing to certify against.
Then nVidia's 6xx series came out and people found the hard way that team green is disabling 3.0 mode with their driver installers for this platform.
There was a lot of fuss about it and certain registry changes began to circulate, that would enable 3.0 mode on these cards. nVidia then went ahead with this public statement and the release of a tool that
would basically apply and revert these registry changes directly so GEN3 support could be manually enabled on X79: nVidia Statement & Tool
My own personal testing, while profiling code, showed several driver stalls/timeouts when GEN3 support was enabled. The driver could actually recover from (in most cases) BUT it did actually slow the performance down, as was expected. I went ahead and tested 8x SB-E CPU samples that I had access to and the results where similar. The difference was in severity of the issue only. Some samples produced stop errors, others seemed fine when in fact they were not.
The result of this was me acquiring a personal habit of suggesting, to everyone asking for advice, to not enable GEN3 support on this platform at all. There are no benefits from GEN3 anyhow since the bandwidth of GEN2 is still not getting saturated by the top end cards.
Now that this background info is out of the way, I can get to the point that the newly released Ivy Bridge-E CPUs for the X79 platform solve these issues. X79 platform owners can now utilize PCIe GEN3 without any issues whatsoever!
Of course the benefits of doing so are still non-existent. Perhaps GEN3 RAID SAS/SATA HBAs can benefit from it but when it comes to video cards, you will not see any performance increase that is outside the margin of error unless you are utilizing huge "Surround" type resolutions. 4K monitor booths anyone?
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