[hardocp] R9 390x with 99.7% scaling in ROTR Crossfire

[Shmee]

Really, they have 4 GB 390s now?

 

[redzo]

Why this need for 4GB 390s? A pair of OCed 4GB 290s would have been fine since 290 is 99% the same 390 chip.

 

[Shmee]

That is what I figured lol. I looked them up, but are they only on the Chinese market? Some articles said they would not be on US and EU.

 

[guskline]

Shmee, our 290 CFs seem to have some "staying" power!:thumbsup:

 

[Mahigan]

There is additional memory overhead involved with crossfire. There were some graphs of GTAV running with decent averages and mins with a single 290 and much higher averages and very low mins on 2xCF (via 295x2). I don't know how much it is but it exists. Now, I'm not saying that is the case here. There is not evidence to say one way or the other without more specific testing. It is certainly possible if the game is right on the precipice of 4GB.

An easy test to help zero in would be 2x 4GB 390's now that they exist vs 2x 8GB 390s and see what happens.

There is no memory overhead. There is CPU overhead.

 

[therealnickdanger]

Very impressive, indeed! I hope this is a sign of things to come from RTG. Didn't even need DX12 or Vulkan to do it...

 

[omek]

There is additional memory overhead involved with crossfire. There were some graphs of GTAV running with decent averages and mins with a single 290 and much higher averages and very low mins on 2xCF (via 295x2). I don't know how much it is but it exists. Now, I'm not saying that is the case here. There is not evidence to say one way or the other without more specific testing. It is certainly possible if the game is right on the precipice of 4GB.

An easy test to help zero in would be 2x 4GB 390's now that they exist vs 2x 8GB 390s and see what happens.

Yeah, I tried it with two 290Xs when GTAV released and it was a bit of an odd type of stop or intermittent halt (not so much a stutter) which would only happen when driving. Not sure if it's still happening but I believe it was narrowed down to memory management problems as it was doubling video memory usage when using CF and constantly swapping in and out. It was a bit of an anomaly.

It's definitely not indicative of a properly configured game for CF use but it was actually extremely smooth when you weren't flying down the at 100mph which probably meant that the frame timing without the halt was near perfect.

 

[Squeetard]

I'm playing ROTTR with 7970's in xfire. Tweaked it with a combo of medium high and ultra settings. Silky smooth and 80+ fps.