I'm spec'ing a build for this summer, and trying to decide on that most important of components: the Video Card.
Based on my research, and my philosophy for the system, I'm thinking my best bet would be a 680 with 4GB of memory.
My thought is that when the time comes that the 680 can't handle what i'm throwing at it by itself, and I add another 680, the 4GB will be more useful. From what I've been able to gather, when two gpu's are in SLI, each card's memory keeps a copy of the same information, so the 4GB will give the SLI set up more capability to reach its potential.
Current plans are either one 1920x1080, one monitor at 1440 vertical, or maybe 2 1080's, though I personally don't much like gaming on two monitors due to the discontinuity of the image, I also may consider an Occulus Rift at some point if that project reaches its potential at consumer launch.
The second part to the question is about the Mobo, SLI, and PCIe. If a board only supports 2 cards at 8x each, is that going to be a bottleneck? Should I spring for a board that supports 2 cards at 16x for future proofing?
Let me know what you guys think.
Other system specs are pretty standard:
8GB of DDR 1600 (2 x 4GB)
2x Samsung 840 Pro @ 128GB each.
Thinking the NXZT Phantom 410 for the case, and the ASRock Z77 Extreme6 for the Mobo, though those may change based on the answers to this thread.
4GB is a good investment if you will definitely SLI down the road - though a 670 is better bang for your buck. Shoot for the 2650x1440 monitor - you can pick a great one up for $400 at MicroCenter if there's one near you. And 8x 8x is good - you won't notice the performance difference.
the 670 is a much better value, performing within less than 5 fps for 100 dollars less. and also note, the 4gb versions are useless. its been proven that extra vram made zero difference in gaming even at 5760x1080p resolution. in fact, the 4gb versions tend to perform worse
I've have actually been changing my perspective on the VRAM issue. I'm now starting to think that the 4GB is a good idea. Before, it was clear that 2GB would be enough in everything but heavily modded Skyrim. But now Crysis 3 is there, just about 2GB and above, and so it won't be long before you will want more, particularly with an eye to the future.
And, yeah, the GTX 780 is supposed to come out at the end of May with 5GB of VRAM, so it might be worth it to wait. On the other hand, the free Metro: Last Light offer may expire before then as well.
So you need to wait at least until next month to get a handle on what all exactly is released, their performance, and the new prices on everything, AMD included no doubt, as they will probably lower their prices making the decision more difficult.
As for the RAM, yet we are just beginning to see where 2GB isn't enough in rare cases, even at 1920X108 in Skyrim with an ungodly number of custom add-ons. But in 3X1920X1080 you can see much more often where the 2GB limit is reached. And believe me, when you run out of RAM, you are out of luck, the FPS drops like a rock over a cliff, totally unacceptable.
Per the Big Troll, it's not all that clear though. I read an exhaustive test where they purposely examined how real the 2GB issue was. It boils down to this:
A single or even dual SLI 670 simply doesn't have enough graphics horsepower to use more than 2GB of ram. As you approach 2GB, the FPS will be dropping and you don't want to be there gaming anyway, you will reduce the AA or whatever before you run out of ram and your game starts stuttering with second long pauses. They showed that you actually need a triple SLI 670 before you can have decent performance using more than 2GB ram.