I just watched Logan's black friday recommendations video and I'm considering building a 4K gaming rig, if what I have in mind is feasible. What interested me the most was the price drop on the 295X2.
I don't want to pay for an X99 + Haswell-E combo. But the mainstream LGA 1150 platform tops out at 2 GPUs with 8x PCIe lanes each.
I was wondering if I could bypass this limitation and use 4 GPUs by having 2 cards with 2 GPUs each such as the 295X2 has. Does a dual-GPU card need the same number of PCIe lanes as two single-GPU cards?
If putting a dual-GPU card in an 8x PCI slot doesn't bottleneck it and make it so each GPU is running as if on a 4x slot, then I intend to put 2x 295X2's in 1150 MoBo with 2-way SLI/CFX support. Pair it with a 4690K and I get an "affordable" 4-GPU 4K rig.
Well, the only thing you can do is research. Overclock3d, or OC3D did a 2x 295x2 rig a while ago, just so you can see some numbers.
https://www.youtube.com/watch?v=LPZe244Ufv0
As good as the price is for the 295x2, i'd just go with 2x 980. Good performance on 4k, and a hell of a lot less power consumption, so you won't need a 1500w psu.
2x 295x2's not only will have loads of driver issues but crikey the heat will be terrible. In all honesty its a piss poor design - 2 hot cores with a single thin radiator. No thanks. Good I suppose if ones house is lacking a fireplace or heating..
Nice 4k gaming on the current crop of gpu's is a stretch, probably the next gen as well. I personally on see 4k being useful for large size tv's, until graphical grunt catches up.
You could probably get a nice triple 27 ips monitor setup with sli 980's or 2x 290x's for less.
The problem is that both Newegg's and OC3D's quad-crossfire tests were run on an X99 platform. What I was looking for is a similar test but on an LGA-115x platform to see if 4-GPU scaling is as good as on the X99 platform.
I know there are 115x main boards with PLX chips that scale for 3- and 4-GPUs as well as the X platform. But those add latency. And the advantage of having a quad-crossfire over a 4-way crossfire is that two cards have distance between them and are not choking for air.
As for why I'm reluctant to go for 2x 290X / 2x 980 is that the performance at 4K is just at the edge of playability so it won't be futureproof. Not to mention that some games, e.g. Crysis 3, are not playable at 4K with just two of those cards and require 3x 290X / 980.
It looks like I'll be waiting for the release of the 390X which should leapfrog the 980's performance. Then I'll just do a 2-way CFX of 390X and avoid the issues that quickly arise after you're crossfiring more than 2 GPUs (e.g. poor game support, air-choked sandwiched cards, etc.).
The 4790K is a bit better than the 4690K in a couple of games. Not enough to justify the ~$100 price difference IMO. Yes, it's considerably better at productivity / video rendering and such. But if that's not a concern for you personally then it's better to go for the i5.
As for the LGA 2011-3 processors. Their extra cores do give better performance in productivity applications, but in games they're going unused. And if the recent trend in gaming towards low-level APIs is any indication, the reduced CPU usage will make it so those extra cores will remain unused for years to come.
Intel knows that their processors' performance (at least when it comes to gaming) has been pretty much commoditized and made the same / irrelevant from the 4670K up. They know that what really matters now in terms of performance is not the processor's number of cores, but rather its connectivity. That's why they moved the 5820K down to 28 lanes, where the 4820K had 40 lanes.
If the 5820K still had 40 PCIe lanes and was priced at or just above $300. I would have just gone with the X99 platform: 5820K + Gigabyte X99-UD4 which has support for 4-way crossfire.
In games that *would* be able to take advantage of double 295x2's , then HT is used ( BF4/Crisis) except for that , the second 295x2 is useless , and the game is not optimized for HT .