Performance increase of Crossfiring 280X?

[Jimdriver2]

I've not used Crossfire before, but all these E3 videos have me wondering what it would take to really max out settings on games.

I've got an i7 4770K, a G1 Sniper Z87 and an MSI R9 280X. It runs most things really well, BF4 is 1080p @ ~60fps in Ultra (with x2 MSAA I think).

But I recently got a bit of a bonus at work and the temptation to max out all these new games is considerable...

I'd need to get a new PSU as well, currently I've got a XFX 550W which runs brilliantly but doesn't have the cables for a second GPU, and even if it did I doubt it would handle the cards that well. The EVGA NEX750G seemed like a good option to go for.

What I'm wondering is if it would really be worth it? I don't do a lot of upgrading and changing around of my system so I'm not really that familiar with Crossfire and the like. I don't know if there's anything obvious i've missed, like having to factor in extra cooling etc.

All suggestions / comments are greatly received!

 

[Jonnygrunge]

R280X cards scale very well now in Crossfire! I would say go for it if your PSU allows for it, mine draw around 550W at the wall fully loaded!

 

[Five.Stars]

Massive. I will post my results (7970 CF) which is essentially the same, and you can compare your results against them if you happen to have any of the same benchmark tools to compare...

Heaven 4
3DMark (Fire Strike Extreme)
Arkham Origins
Hitman Absolution
Sleeping Dogs
Sniper Elite V2
Tomb Raider

The settings used in each benchmark are linked to in the thread. Your 280X will have slightly higher clocks most likely as my tests were carried out at stock (original 7970's 925 core, 1375 memory). You will find, depending on the game/ benchmark that it will scale anything from 70-100%. Sometimes, there are games that don't play well with CF so scaling is less, but most are well supported.

Again, power supply is something to consider - I wouldn't go CF on anything under 750W and preferably higher. You could, at a push get away with 600-650W, but I would suggest nothing in system is overclocked. Heat is another factor. Given that, to my knowledge, all 280X's vent the warm air inside the case then 2 of them are really going to see internal temperatures increase, so have a think about ways of getting that heat out of the case somehow. If your case has good airflow already, it mightn't be a problem but certainly a consideration.

Here is link to some 7970CF results you could possibly compare to: http://forums.overclockers.co.uk/showthread.php?t=18602962

 

[TonyTurbo78]

go for it man, a couple of 280x in Crossfire will give you more performance than a single 290x or 780ti at a fraction of the cost. My 2 7950's slaughter games, and the 280x is slightly better than a 7950. There are zero issues with Crossfire these days, it gets bad press but I can't speak highly enough of it.

Regarding cooling, if you have them close because of the PCIexpress slots on your mobo, if you can put a fan on the side of your case to blow cold air on them both, then that would be a good idea. If they are far apart, then consider ones or another one with an exhaust cooler to keep the warm air from circulating inside your case as much as possible. Mt cards sit within an inch of one another, I have a 120mm fan on my window that blows cool air on the, which keeps my temps on both cards to a max of mid 60c under full load. The top one generally will be slightly warmer than the bottom one, maybe around 5c in most cases but nothing to worry about.

Crossfire is very simple. Just use the provided crossfire bridge and enable Crossfire in the CCC.

So I'd say definitely got for it. I reckon there is maybe 18 months of life left in these cards Crossfired, it's a real cheap upgrade and will tie you over until the big hitters come in with the 20nm cards

 

[Jimdriver2]

Nice one thanks guys.

Cooling wise I think my PC is pretty decent. It's got three case fans and I've got a 212 EVO on my cpu. The case is a an IN WIN that has a grate over the cards so hopefully a lot of air gets out that way. It certainly stays very quiet so I've presumed that's a sign everything is fairly cool as nothing is having to really work to keep stuff chilled.

PSU wise what would you recommend? Is the EVGA NEX750G a good buy? My XFX has been rock solid, something I can't say for the Corsair it replaced!

 

[TonyTurbo78]

I've never owned an EVGA PSU, but I hear very good things about them. A 750w is probably as low as I'd like to if I was in your shoes. I like to have some room regarding wattage, a 750w should do you nicely, but an 850w might be a better idea if you can stretch.

 

[Avenged7Fold]

I think EVGA PSUs are done by Superflower. If that is right, then 750w would manage.

 

[jimhaumman]

R280X cards scale very well now in Crossfire! I would say go for it if your PSU allows for it, mine draw around 550W at the wall fully loaded!

I thought with your clocks on the cards it should take more than that...
550W is not much.Did you try Sleeping Dogs?I'll have my second card tomorrow so 550 is very good news to me.

 

[ICDP]

I used CF 7950s and while they were definately faster than my single 290X I prefer the 290X.

Far too much hit and miss with CF profiles in the majority of games. AAA games mostly work out of the box but go to the non mainstream games and you run into serious problems.