My current rig should be listed in my signature. I am ready to gear up and future proof myself for the next-generation. Here is what I am looking to do:
1. Upgrade my 2500k to a 3570k - with the next-generation coming up I feel the 2500k may bottleneck my next pair of graphics cards.
2. Looking to go with either two 7990s for quadfire or two 8970s for crossfire - I expect the 8970s to be around $700 and I can get a pair of 7990s for quad-fire for about $1500 right now. I know the thing about going with the best card but I can handle a multi-gpu configuration. The question I have is which I should go with. I am thinking that the 7990s would give me more oomph but would I get a VRAM bottleneck? On Crysis 3 my VRAM may already be bnecking me as it's the only game I can't max at a good framerate, and I only game in 1080p.
3. I wonder about my motherboard. It is the Asus P8Z68-V pro, and it only has a two PCIe slots, one 16x and the other 8x - would that handle two dual cards if I went with the two 7990s or would I have to upgrade that also?
4. My RAM is weak. Yes, I have 16GB of it but it's 1333MHz - there are laptops out now with faster RAM. Should I dump it for 8GB of faster RAM (which may make overclocking my new CPU easier - less RAM)???
2)I havent heard about a 8970,but maybe you mean the new amd R9 series and in particular the R9290X.It's not on the market yet so prices can't really be predicted.
For the money i would't get the hd 7990 x2,i think you would be better off with 2xgtx 770 or R9280,the latter being the cheapest solution.They should be able to play crisis3 to the max i think.
If you really want to spend money you could go for 2xgtx 780 or when it's there the R9 290x.
I don't think quad crossfire will work very good looking at the reviews,or at least that you will benefit hugly from it.
Crysis likes nvidia so keep that in mind.And no i'm not a nvidia fan,it's what shows in the reviews.
You might go for the 4gb version of the gtx 770 to be sure or if you think it's nessesary.With 1080p 2gb should already be fine i think,but that's your decision.
I read about BF4 that 3gb Vram already is recommended,so games probably will end up using more and more Vram.
3)I don't think x8 wil bottleneck and if it will it won't be so bad that you have to upgrade your motherboard.From what i remember x8 only gives about 2% maybe up to 4% less results than x16.
4)Your ram will probably stil be the fastest part of your pc,so it wil do just nicely.You could try to overclock it,but that's something you have to decide for your own.
Whether 4 modules hurt your overclocking i don't know,i don't think so (i'm not such a die hard overclocker) because with the way you overclock these cpu's you don't involve the ram that much because it's done mostly by altering the multiplier and hardly the bclk.The ram will only go higher accordingly when you alter the bclk,which you can do but not as much.Google this yourself if you want to be sure.
Just try it with what you have is my advice.
I didn't look at your pc specs before answering so some things are a bit redundant.