Driver Limitations And SLI-AA Mode
SLI, unfortunately, is not without its downsides.
If you're a fan of Dynamic Super Resolution (DSR) and Multi-Frame Anti-Aliasing (MFAA), two of Nvidia's new Maxwell-specific technologies, we have bad news for you: they are not supported in SLI under Windows 8.1. If you enable SLI, those options simply disappear from the Nvidia Control Panel. Users have reported that these do work under Windows 7, although we have not verified it ourselves. We asked Nvidia about driver support in SLI for both technologies and received the following answer:
"MFAA support for SLI configurations will be coming in a future driver release. DSR support for SLI is supported in some circumstances. More robust hardware configuration support will be coming in future driver releases."
What you do get is an SLI-exclusive anti-aliasing mode called SLI-AA that can be enabled through the Nvidia Control Panel. The company went back and forth on including this feature in its drivers. It was missing for a while and is back now. While you generally won't use it much, the option does allow you to essentially force MSAA on in DirectX 9 games that don't natively support it, and where you don't need the extra performance of SLI or where SLI AFR rendering is not supported at all. It won't work in DirectX 10 or 11 games, so the value of this feature in modern titles is negligible.
The above example illustrates the use of SLI-AA 16x compared to Blizzard's built-in FXAA support for Diablo III. You'll notice that SLI-AA produces a sharper image overall, but, like all MSAA-based techniques, does not remove aliasing from transparent textures (the banner, in this example). Click on the image to expand it for a better visual comparison.
Do you think we'd see 1080p monitors with 200hz+ in the future? Would it even make a difference to the human eye?
I also believe that alternating frames is utter crap. The fact that this has become the go to standard is a travesty. I dont care for fake fps, at the expense of consistent frames, or increased latency. If one card produces 60fps in a game. I would much rather have 2 cards produce 90fps and both of them work on the same frame at the same time, then for 2 cards to produce 120 fps alternating frames.
The only time 2 gpus should not be working on the same frame, is 3d or vr, where you need 2 angles of the same scene generated each frame. Then ya, have the cards work seperatly on their own perspective of the scene.
However, If i need to buy 2 980s to run a VR set or a 4K display Ill just wait till the prices are more mainstream.
I mean, in order to have a good SLI 980 rig you need a lot of spare cash, not to mention buying a 4K display (those that are actually any good cost a fortune), a CPU that wont bottleneck the GPUs, etc...
Too rich for my blood, Id rather stay on 1080p, untill those technologies are not only proven to be the next standard, but content is widely available.
For me, the right moment to upgrade my Q6600 will be after DX12 comes out, so I can see real performance tests on new platforms.
I had my eye on the two Acer monitors, the curved 34" 21:9 75Hz IPS, and the 27" 144HZ IPS, either one really for a future build but this piece of info tells me my i5 will be a problem.
Could it be that Intel CPUs are stagnated in performance compared to GPUs, due to lack of competition?
Is there a way around this bottleneck at 1440P? Overclocking or upgrading to Haswell-E or waiting for Sky-lake?
While true from a certain perspective, it should be clarified that you need 2 of the same number designation. As in two 980's or two 970's. I fear that new system builders will hold off from going SLI because they can't find the same *brand* of card or think they can't mix an OC 970 with a stock 970 (you can, but they will perform at the lower card's level).
PS. I run two 670's just fine (one stock EVGA and one OC Zotac)
What you say -was- true with 6xx class cards. With 9xx class cards, requirements for the cards to be identical have become much more stringent!