Originally Posted by Sexparty
You realize that with the way sandy bridge-e works and ivy bridge works that if you were stuck at PCIe 2.0 16x/8x/8x on a X79 board that it would be the same as running PCIe 3.0 8x/4x/4x on a Z77 board yeah?
Ivy bridge only has 16x PCIe lanes to work with whilst sandy bridge-e has 32x PCIe lanes to work with.
I would do everything possible to keep the 3930k CPU (since it's much better than any ivy bridge chip) and either just enjoy it or try and get the sandy bridge-e system to work at PCIe 3.0 speeds. This of course is up to Nvidia's drivers at this point since I haven't heard anything on them re-enabling PCIe 3.0 on sandy bridge-e systems since release? PLX chips on the Z77 chipset are nice and such but don't address the actual issue at hand. Seems Nvidia are buying into Intels bull**** and not enabling it because X79 isn't offically PCIe 3.0 although it works perfectly fine at those speeds.
So consider doing the un-thinkable and choosing AMD if it's that important to you 'right now' because the HD 7970s seem to work fine at PCIe 3.0 speeds on X79 platforms.
Either downgrade to a ivy bridge platform so you can run native, supported and hassle free PCIe 3.0 at 16x with a GTX 690 (on something like a sabertooth board because spending money on a Z77 platform with limited bandwidth is waste of money, I know, I have an ASUS WS Revolution board and it does not solve the issue) or stick with sandy bridge-e (and upgrade to ivy bridge-e at the end of the year) and run 3x SLI on a X79 board which esentially will give you the same performance as 3x SLI on a Z77 system. More if you can get it to work at the faster speeds.
My main concerns are of the wasted GPU power of running 3x 680's on the x79, with only being able to get PCI-e 2.0 8x speeds on 2 of the cards.
What I really want someone to say is 'Yes, you can enable PCI-e 3.0 on the x79 Rampage IV Extreme using the registry fix with no problems'.
My worries are that if I purchase it and I cannot enable PCI-e 3.0 using the registry fix (crashes/boot issues). Then I'm stuck with PCI 2.0 8x speeds, which will limit two of the cards as Vega has shown in his youtube videos.
I'm comparing the z77 platform (Sniper 3), which can run 16x 8x 8x PCI-e 3.0 (yes I know about the lanes limit, but probably a lot better than PCI-e 2.0 8x limitations). I will change to this platform if it really is going to benefit me to get the most from my 3 cards.
I am not overly optimistic about Nvidia actually enabling PCI-e 3.0 on x79 officially. I also don't want to gamble on IB-e (in case it never comes and even if it did I really want to make a decision now based on my GFX card purchases and current tech).
I'm curious if Vega could share some light, as I 'think' he may have used both systems with multiple cards.
The AMD series cards are of no use, as I'm using a Catleap 2B (1440p, 100hz). Currently with Crossfire, as far as I know, you cannot get over 85hz at 1440p of which I want 100hz (so Nvidia only).
The thing that is puzzling me is Vega mentioned he couldn't enable PCI-e 3.0 using registry fix without boot problems in one post. But on another (and in videos), he is using the registry fix and is using 301.10 (which didn't have 3.0 support natively). So am I to assume, he managed to correct the registry fix to make it work with newer drivers?.