I'm considering tri sli and have ordered the 5820k. I do realize that the 3rd card would run at 4x. How much if at all would that limit that card? I'm considering returning it and getting the 5930k but would really need to justify the loss of performance. I know that PCI-E 2.0 and 3.0 carry no performance difference at all and even 16x to 8x don't perform differently at all either.
I don't think it will be a huge bottleneck but it will definitely have a negative effect. I know it costs a little more but surely 2 x 980s are a better choice? In a lot of cases it'll be faster because 3x SLI wont work, produce less heat and you wont have this PCI issue.
I'm not sure, but I've read once that sli more or less 'uses' only the lowest bandwidth available to a single card... so you'd see 3.0x4 or 2.0x8 performance on all.
How come it will run at x4? On my board it would run at x8. The 5820K has 28 lanes so it supports tri-SLI at 8 / 8 / 8 given the motherboard supports that too of course.
Hey if ya wanna go 980 GTX SLI route. I have an extra EVGA 980 GTX does 1500/4000 and I would do a a trade deal for your 970 GTX SLI. Just saying PM if interested.
This is correct, apparently I have a problem adding today. I suppose the performance really wouldn't be hindered in that case.
I would not get 2 980 coming from 2 970. I would go more than 2 way sli either. Less headaches. I am going to see what a couple gm200 looks like when released. That should be a major upgrade. Not this nickel and diming upgrades that are out now compared to 970 sli and 780ti sli.
Thanks for your input, but that doesn't help me decide what I'll do. What's the reasoning behind it???
Reasoning being tri or quad SLi is super inefficient the few times it actually works, thus dual 980's would cost ~same be more reliable and perform about the same
Scaling, lack of support relative to dual, stutter, additional frame of lag (AFAIK) over dual since AFR is also used (alone) for 3-way multi-GPU setups are potential issues.
I ran 295 quad sli in this rig for a short time. Scaling was terrible. More stuttering. Only things that ran real good were the futuremark benches. Won't go more than 2 way again.
As others have mentioned, there was a multitude of issues with it... much increased cpu overhead, more input latency, and most importantly - little to no tri / quad sli support in most games. What im basing it on tri sli with 8800 gtx and quad sli with gtx 295... the games that DID work with quad sli, ran like crazy with it though - like far cry 2... single gpu i got 40 fps, with quad sli i got 110! But as said, my experience was / is that barely any games offer support / good scaling.