3 x stock 7970 Lightning vs 2 x OC'd 7970 Lightning?

[Andybtsn]

I don't just mean in this current gen but for future too. I'm not sure if it's worth keeping the 3rd GPU in the system at the moment, but future it maybe beneficial?

I can't OC the 2nd and 3rd GPU as they sit so damn close and there is no cooling. I can't really justify spending more money on the system for water cooling neither.

Whereas I could have 2 and keep trying to get the best out of them? I'm not sure if the 4770k bottlenecks the trifire setup anyway.

Opinions?

 

[RichardH754]

I am thinking the same thing

 

[Phixsator]

I dont think the scaling will be that good on a trifire system even with a 4770k under the hood IMHO. But again its difficult to say simple because we do not know the resolution you are going for.

I would think that 2 7970 lightnings will perform better overall removing the trifire issues that may occure and you will also be able to OC both even further since you dont have that 7970 in the middle hindering airflow. Also they will have more than enough horsepower for the foreseeable future.

 

[Andybtsn]

I game at 5760x1080 for the record.

 

[Phixsator]

I game at 5760x1080 for the record.

Would be simple to figure it out. Find a few games with a build in benchmark(3dmark wont paint a proper picture anyway) and test out your system with 2 and 3 cards installed at stock CPU speed and then the same after you have OCed the 4770k. The scaling should be pretty clear.

I would guess that you would get a fair bit of higher maximums with 3 cards but the minimums would be fairly close to 2 cards which is why i personally think it may not be worth it.

Give it a go and post the info you find. might help someone else to

 

[Make]

The 4770k will bottleneck three cards unless you can reach insane clocks for 24/7, like 4.9ghz.

I'd think 3x non-OC lightnings will beat 2x normals, as you can't get a +50% performance per card from OC. I know everything doesn't scale as well on tri-sli, but still. Besides, even if the cards sit close, you could still manage a small 5-10% OC.

Also consider doing some weird cooling mods, like inverted airflow from behind (zip-tieing a cooler outside the case on the PCI-slot covers to blow in, the cards do not blow out anyway mostly). Anything for performance!

Simple option is to keep just 2 though.. and you'll still want to OC that CPU as high as you can, two need a lot of grunt in some games.

 

[GoogalyMoogaly]

Can't remember which motherboard you have Andy (Z87X-OC?) but on a lot of Z87 board doesn't it drop the bandwidth to at least one card to 4x (if not 2)? Isn't that the reason few board support Tri-SLI?
I know it's PCI-e 3.0, but still maybe that will have an impact?

 

[Besty]

Buy another 7970 and the asus 4k screen

 

[JediFragger]

True, I'd think about your mobo tbh and think if it's going to strangle performance with the 3rd slot...

Surely 2xLightnings will kick ass for a looooong time to come?? REALLY love the look of those cards too, cool as

 

[Andybtsn]

I sacked the third one off for now, the noise of the fans were doing my head in! In EyeFinity the middle GPU was about at 90% speed, was driving me crazy!

The wife's machine can have a nice 7970. Shame I bought a new PSU to accommodate the third GPU but at least it's future proof and a nice energy efficient one.

Shame you can't get extra large mobo's to allow for air cooling as these GPU's are just too damn big!

 

[ToxicTBag]

Just make sure you gift wrap the gpu before handing it over to missus make out like you got her summat she's allways wanted

No sign of them there copper strips on your new case?