7990 for 1440p?

[hoorhay]

I'm putting together a brand new build which will be meant for video editing with sony vegas and 1440p gaming.

Every part is brand new aside from a 7990 that my friend has spare. He originally bought two when they released, but after literally three days of doing essentially quad-fire, he gave up due to temperatures resulting in throttling. He sat it back in it's box with the intention of doing a custom loop so he could throw it back in. Never happened. So it's sat in it's box all this time, almost new condition.

My question is how would it perform at 1440p on titles that support crossfire. I'm not looking for narrow answers saying I'll only get the performance of a 7970 on games like CoH 2. I know. Just curious how the relative performance of a 7990 would be at 1440p?

Rest of my build.

i7-6700K
Kraken X31
ASUS Z170 Pro Gaming
Corsair Vengeance 2x16GB 2666mhz CL16
Samsung 850 EVO 500GB
Corsair 750D
Corsair AX750 (I'm guessing the original AX series? Dunno, it's new at micro center for $75. Asumming it's the same quality as other AX/HX series units)

 

[photonboy]

Every game varies, so just experiment yourself.

I play most games on 1920x1080 (single GTX680, i7-3770K) but do play several at 2560x1440.

*It's worth noting that a lot of games don't look much better at 2560x1440. For the most part it's whether the game has a lot of SMALL TEXT or other elements like CIV5, SC2 (most top-down "god" games) though a lot of MMO's have small text as well.

**Lots of CROSSFIRE reviews. I'll post one after this.

 

[photonboy]

https://www.techpowerup.com/reviews/AMD/HD_7950_CrossFire/23.html

That is an AVERAGE of a lot of games, and also a few YEARS ago. Drivers have improved and some newer games scale much better.

You can look at individual games here too but your results now should be as good or BETTER.

THIS video is for the R9-390X in Crossfire, http://gamingtilldisconnected.com/2015/09/msi-r9-390x-crossfire-review/18931
..again games vary, but it's useful since:
a) GPU architecture is basically the same, but
b) Newer drivers (crossfire tweaks etc).

Other:
In the future DX12 should hopefully enable better scaling.

(Remember you have a usable 3GB framebuffer not 6GB for all current games. DX12 may allow adding not cloning. Rarely going to be an issue for you though right now as more than 3GB is pretty rare though GTA 5 and a few others can depending on settings.)

 

[17seconds]

It's about the level of a GTX 980/Fury.

Here is Guru3D's power supply recommendation:
•Radeon HD 7990 - On your average system the card requires you to have a 750 Watt power supply unit.
•Radeon HD 7990 Crossfire - On your average system the cards require you to have a 1000 Watt power supply unit as minimum.

If you are going to overclock GPU or processor, then we do recommend you purchase something with some more stamina.
http://www.guru3d.com/articles_pages/radeon_hd_7990_review,8.html