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DirectX 12 woes!


#1

So, for a laugh I decided to test if my old crotchety XFX 7970 GHz edition could reap any benefits from DirectX12. Now, from what I've been able to gather all GCN AMD GPUs should support DX12, even if AMD lists the 7000 series as "laptop" cards these days.

According to dxdiag DirectX12 is installed however it only shows my card functioning up to DX11.1, as such no games are drawing any frames on screen if DX12 is set as the renderer in game! I have no idea why this doesn't work, it should. It's worth mentioning that I am really bad at googling.

Anyway, here's a random video that apparently shows that dx12 is working on a 7970: https://www.youtube.com/watch?v=o2gmLS8QLm4 the menus are in Cyrillic so I have no idea, but the performance number overlay says dx11 and dx12 so, I guess? Obviously not much of a performance increase, but I'd like to test for myself.

Is it simply a case of the card being so old that it doesn't support DX12 on a hardware level and that's why it's not showing in dxdiag properly? Could it be because I've messed too much with Win10 to minimise the level of big-brother going on? Should i just give up on my dreams of gaining maybe 0.5fps in some DX12 enabled games?

Anyway, system specs:

http://imgur.com/a/SQWlP

Pretty crusty and old, but still. Again GPU-Z tells me that DX12 is supported but has 11.1 in parenthesis.. So what the heck is going on? Why does it not work?

Thank you for your time and any replies!

P.S. Current ETA for planned new HW T-4 months.


#2

It's a smidgeon too old and is not fully compatible with higher than DirectX 11.1


#3

7970 supports most of dx12 features. - you could say it does support dx12.
(some time ago i ran battlefield 4 in dx12 on 7970 to test it - gain was there - minimal but there.)

  • Note: Some people on yt tested 7970's against other dx12 titles.

  • the spec of dx support is written to a bios, it does not reflect anything at all. When you edit bios you can specify DirectX 14.2 for all it cares - that's how it'll be read. It doesn't mean it does support it - its just something written in its identification code. Take 290x as example, the dx12 wasn't there yet, but 390x which is exactly same card had written dx12 support in that field.


#4

Thank you for your replies mkk and CyklonDX. I've come to my senses and won't pursue this endeavour any further.

Essentially after reading a bit more while yes GCNv1 supports DX12, it's not DX12 at a hardware level which means it's simply running emulation. DX12 could help me by enforcing better multi-core use, but look at my pc it's not going to benefit that much if at all. So overall I'll just pretend I'm happy with what I have and pull the trigger on a new system in ~November... If I can hold off that long.


#5

no, you are wrong there. GCN (so called v1) does have hardware level support.
One and most important feature of dx12 is resource binding, and stencil reference value from pixel shader. (which is why some of the older nv gpu's don't perform so well, that and architecture design of GCN in itself allows for multi-context rendering; where nvidia demands single context at the time.)


ref.

-- GCN 1 would or should be called originator of dx12, (aka. based on mantle)

If you wish to see full use of the feature you should try
Ashes of Singularity or Doom -- the fps difference will be obvious there.

after first google on the 7970 doom vulkan i got this: -- it speaks for itself.


#6

7970 is a champ at newer api's

currently in my brothers machine and running doom (vulcan) beautifully.

There doesnt really seem to be ANY poster children for a GOOD dx12 game yet other than Gears of War 4.