NVIDIA'S ANSWER TO X79 AND PCI-e3

[tommybhoy]

Just out of interest, vega put this up elsewhere, look what happens when you enable PCIe 3.0 with the patch on 4x680's:

I don't know if you can post the link or not but it can be found in the comments on techpowerup's article about the patch:

http://www.techpowerup.com/forums/showthread.php?t=168027

 

[Kaapstad]

The 690's have an internal bridge chip that runs at PCIe 3, even on PCIe 2 boards.

I know the 690's have an internal bridge between the 2 gpus that runs at PCIe 3. But they also talk to the outside world @ PCIe 3 which is a separate matter.

 

[whyscotty]

Just out of interest, vega put this up elsewhere, look what happens when you enable PCIe 3.0 with the patch on 4x680's:

Many thanks for that link.
It goes to show that it does make a difference especially on surround setups,
sli gains between 8-18% on a single 1080 monitor and more as the resolutions get larger.

I really didn't think you could get that much of a gain with 680 sli,scroll down to the BF3 testing

http://www.overclock.net/t/1220962/vegas-heavyweight-display-and-computer-edition-2012/400

i hope i was ok linking this if not apologies

 

[mmj_uk]

I know the 690's have an internal bridge between the 2 gpus that runs at PCIe 3. But they also talk to the outside world @ PCIe 3 which is a separate matter.

Indeed, GPU-Z etc might just be reporting PCI-E 3.0 because that is what speed the GPU's are connected to the internal bridge at, it should still be the case that the CPU to PCI-E bus is where the problem lies and hence the drivers are limited to PCI-E 2.0 externally.

At the end of the day this may only affect 5% of X79 system but NVidia have felt it's better to force PCI-E 2.0 and ensure stability all across the board. AMD could well be affected by it as well but just haven't realised yet.

There's not much the GPU vendors can do when motherboard manufacturers are not keeping to PCI-E standards.

 

[PCZ]

The exe NV released makes enabling pcie3 easier as previously you had to do a registry edit to get pcie3 signalling speeds.
It changes the same registry key just makes it a lot easier.

PCIe3 works fine for me on the ASUS x79 pro and x79 Sabretooth, but is a no go on the AsRock extreme 4
I don't have any more boards to test, perhaps others could report success/failure with different brands.

On the AsRock with pcie3 enabled it either freezes up at the desktop or imediately any 3d video is run.

I have noticed that with pcie3 enabled minimum frame rates increase significantly.
Data is loaded into the cards faster helping when it is needed most.

Max frame rates do increase slightly , but is of less importance than the min and average rates which do get a nice boost from the increased signalling speed.

The example shown with the quad 680's shows massive gains but the benefits also apply to those of us with more modest setups with dual SLI,. just to a lesser extent.

Shame some board manafacturers have botched the pcie3 implementation on X79.
I wil be playing it safe and sticking with ASUS for my Gaming PC.

 

[whyscotty]

As above works fine on Rampage IV Extreme,similar results fps has increased large gain on min fps not noticed any issues as yet.
From the reviews/reports that are appearing since this patch release it does seem a board issue as opposed to NVIDIA being the villain in this!

 

[Zuban]

tried this last night on my msi gd65 x79, not noticed any difference in fps as i'm running only a single 670, but havent had any errors yet. Anyone else tried it with this mobo?

I think it seemed faster loading objects into my 3d software presumably because its loading them into the vram faster but i need to quantify this.