So I tried out Mantle today on BF4... (VERY SAD FACE)

[crystal6tak]

I am...dissapointed. I'm not sure to Dice or to AMD. I'm testing out battlefield 4 with mantle with 14.6. 

CPU: FX-8350 (Stock: 4ghz)

GPU: Crossfire 290X (Stock: 1050mhz, 1350mhz)

RAM: 12gb 1333 mhz

 

For reference to fps numbers and test scenarios, I made this thread a while back to benchmark battlefield 4 settings and I followed the same procedure to get the new numbers shown here: 

http://linustechtips.com/main/topic/82663-battlefield-4-settings-for-gpu-usage-optimisation-guide/

 

Now remember back then I was using a single 7970 oced, now I'm using dual 290x with mantle + months after Dice released the game. These are the dual 290X results I got.

 

Test 1:

API: Mantle

Settings: All highest

FPS: 49

GPU1 core clock: 750 +/-

GPU2 core clock: 900 +/-

(Why is core clocks here? Well, I think it explains the strange numbers, read on)

 

Test 2: 

API: Mantle

Settings: All lowest

FPS: 50

GPU1 core clock: 750 +/-

GPU2 core clock: 750 +/-

 

Test 3: 

API: Direct3D

Settings: All highest

FPS: 37

GPU1 core clock: 900 +/-

GPU2 core clock: 900 +/-

 

Test 4: 

API: Direct3D

Settings: All lowest

FPS: 61

GPU1 core clock: 800 +/-

GPU2 core clock: 900 +/-

 

So what do we see here? with mantle, the highest setting received improvements while the lowest settings somehow is slower than D3D11 at lowest... Now here's the even more baffling part.

 

This is my result with 7970 oced with D3D11 (Mantle was not available back then), 13.11 beta v8

 

Comparison test 1:

Settings: All highest

FPS: 48

 

Comparison test 2:

Settings: All lowest

FPS: 72

 

I don't believe it, a 7970 oced with 13.11 running a few month older BF4 using D3D11 is somehow only 1 fps slower than DUAL 290X with 14.6 running the current BF4 using Mantle. On lowest it's even worse. 7970 achieved 72 fps while dual 290x achieved 61 fps!?!?!

 

Could it be Dice deoptimizing the game or AMD screwing something up with the gpu core clock? I honestly have no idea. If any of you know why this is happening please let me know. Until then I'm degrading back to 13.12.

 

[nj4ck]

that's weird. I get a ~10 fps bump when I turn mantle on with my 290.

[Vitalius]

that's weird. I get a ~10 fps bump when I turn mantle on with my 290.

Same with my 290X. This is indeed weird.

[crystal6tak]

Maybe I'll disable crossfire and do some more tests? But that wouldn't explain why D3D11 is also suffering from bad performance too though...