How do I overclock GPU in Hybrid crossfire mode?

Scougar · 4 May 2015 at 04:04

So.... I saw a 7750 2GB DDR3 and picked it up for 30 dollars, as I remembered I could Hybrid crossfire with my 7850K APU. I know the results were not awesome or anything, but for a little extra I thought why not

(Almost doubled the benchmark scores... but not sure on gaming results yet).

How do I overclock the GPU so I can match(ish) the APU iGPU speed please? (the overdrive option disappears from the menu for some reason)

pandem0nium · 4 May 2015 at 17:31

Last time I checked, that APU can only run dual graphics with a 240 or 250. Are you sure it's not just running on it's own?

Scougar · 4 May 2015 at 17:36

It allows me to run dual mode in CCC, and that's what I have selected. I can get it to display the dual mode gfx logo when running that way as well. Seems to work fine, and my frames in benchmarks are close to double (from what I remember from one quick run last night). Also.. looking up info on the AMD website, it's now called 'dual graphics', rather than Hybrid (which is obsolete apparently).

How I can overclock the 7750 though I don't know (maybe with afterburner or something?) but I would prefer to use overdrive if possible that is built into CCC, if I could enable it somehow?

Orcvader · 4 May 2015 at 18:20

Does it not give you the option to overclock in the Performance tab of CCC? Tried installing the newest AMD drivers?

Surely the 7750 runs faster than the IGP? It should be running at 800/900 MHz on the core compared to the 720MHz on the IGP, not to mention it has dedicated GDDR3/5 memory, the fact that the IGP uses the system memory itself is pretty much a bottleneck.

Scougar · 4 May 2015 at 18:27

No, the option in CCC for overdrive has disappeared :-(

I have downloaded overdrive separately now, and will have a look at that tonight, but I would assume that there is a registry hack for CCC to re-enable the option?

My iGPU is running @ 1028Mhz with 2GB of DDR3 @2400Mhz memory.
The 7750 is something like 800Mhz running 2GB 1300Mhz DDR3. http://xfxforce.com/en-us/products/.../amd-radeon-hd-7750-core-edition-fx-775a-cgfv

pandem0nium · 4 May 2015 at 20:03

Could you post a screen of gpu-z showing that crossfire is enabled? It's not officially supported, so I think the 7750 is just running on it's own.

I'd use Msi afterburner to overclock the gpu.

Scougar · 4 May 2015 at 20:14

pandem0nium said:
Could you post a screen of gpu-z showing that crossfire is enabled? It's not officially supported, so I think the 7750 is just running on it's own.

I'd use Msi afterburner to overclock the gpu.

I'll do that when I get home. And yes, it isn't officially supported, but it does appear to work (as have other cards in the past that weren't officially supported from what I've read.)

Orcvader · 4 May 2015 at 20:50

As above, get a screenshot of GPU-Z for both the 7750 and IGP. Are you sure the IGP is running at 1028MHz? On the AMD site it states it should be running at 720MHz, unless you somehow overclocked it: http://www.amd.com/en-us/products/processors/desktop/a-series-apu

Looking up the GPU and IGPs more, it seems both uses the GCN architecture, with both having 512 stream processors (although the 7750 offers a little more in other areas), so that could explain why it's given you the option for dual graphics as architecture wise they are very similar.

+1 to MSI AfterBurner, see if that allows you to overclock the GPU.

EDIT: I think I just remembered something. Disable Dual Graphics and that should allow you to overclock with CCC. Once you've finished overclocking, you can turn Dual Graphics back on again.

8 Pack · 4 May 2015 at 21:05

This coinfig is not gaining anything at all last time I tested.

Scougar · 4 May 2015 at 22:03

Thanks gentlemen. I am looking at a destroyed gazebo outside my house, so need to see if I can fix that first before I look at this. I quickly tested the single discrete card overclocked to 900/800 (max limits at present) by itself, and it is slower than dual mode so I can only summize till I prove it, that it's working.

I've just downloaded GPU-z in advance though.

8 pack... it is 'gaining something' in Valley benchmark at least... need to test more though :-)

Scougar · 5 May 2015 at 02:37

Ok.... taking a look at this now. Disabled overdrive for the standalone (single mode card) 7750. Now installing Afterburner to see how it clocks etc.

Update 1: On a very short test, 1028Ghz is achievable on the 7750 standalone, but memory max is showing as 870mhz in afterburner.. trying to figure out how to increase that limit (I've already raised the limits to unofficial overclocking but that only seemed to increase the GPU mhz limit, but I can't seem to increase the memory limit.)

Update 2: OK.. so I've lowered the GPU to 950Mhz, and finally got the ram showing as 870Mhz. However, the limit is showing as 870, but I want to push it further... how do I unlock more potential please?

Update 3: So I enabled enabled overdrive on the discrete card, and then in the bios set it to be the primary card. Now when selecting dual graphics, overdrive still shows up. Great. Now to see if it works in this configuration.

Ok... so running both iGPU and GPU at 960Mhz, but memory on the GPU is much slower (870 vs 1200Mhz). Benchmarks are definitely improved scores and framerate.

GPU-Z:
HD7750

7850K R7 APU (iGPU)

Note that I'm also running my CPU at 4.4Ghz with throttling disabled, so no dropping to 3Ghz (Do this via software so when the powerstates change, you just keep it at the same overclock).

Update 4: Not really sure if Planetside 2 is the best example to use with crossfire, seemed to do ok though. Heaven 3 scores went from 630 using just the GPU to 1224 to using iGPU and GPU together (1680*1050, 16x AF, no AA, normal tessellation). Will need to fiddle around with it more, really want to get my memory speeds on the GPU up though.

Update 5: You know what I think it is... when in dual graphics mode, I think you have to select the desktop you want to show... and it was on my 2nd monitor which I assume is running from the APU rather than the GPU. When I swapped to the other desktop the overdrive option appeared again.

Scougar · 5 May 2015 at 16:24

One thing I noticed last night was there was noticeable stuttering in PS2 last night. It was pausing momentarily every second or so. Extremely annoying. I don't remember it being like that the first time I tried it. I have changed a few things, like manually selecting a planetside2.exe profile, and making the discrete card the primary one rather than the APU.

Orcvader · 5 May 2015 at 17:21

I would advice sticking both your monitors to the 7750 for best performance.

As for the memory, don't worry about it, the 7750 is using GDDR3 which is designed for GPU use compared to DDR3 which is designed for CPU use, so even though it's running at a slower speed, it should still offer better performance than the DDR3 the IGP is using. If anything, it would still be the DDR3 memory the IGP is using that will be the main bottleneck.

ALXAndy · 5 May 2015 at 18:20

Can you enable Frame Pacing with that set up? it's critical in some games for preventing stutter.

Scougar · 5 May 2015 at 18:37

ALXAndy said:
Can you enable Frame Pacing with that set up? it's critical in some games for preventing stutter.

Hmm.. it 'was' enabled I'm pretty sure previously.. I wonder if I did something to disable it. Thanks ALXAndy, I'll look tonight.

I will need to work out how to raise my max memory limit for my 7750 though, I'm sure it's holding the discrete card back.

pandem0nium · 5 May 2015 at 22:58

Fair play, the 7750 is a faster card than the other cards you can run in dual graphics mode.

Theres a checkbox in afterburner options that should allow you to extend the official overclocking limits. Or you could use vbe7 to edit and re-flash the bios of the card.

Scougar · 5 May 2015 at 23:19

pandem0nium said:
Fair play, the 7750 is a faster card than the other cards you can run in dual graphics mode.

Theres a checkbox in afterburner options that should allow you to extend the official overclocking limits. Or you could use vbe7 to edit and re-flash the bios of the card.

Already tried extending the limits in afterburner, and it only extended the core, not the memory :-(

(That was only with a check box though)

I haven't heard of vbe7 before though...

EDIT: Sapphire TRIXX seems to allow me to go beyond 870mhz on the memory :-)

Edit 2: frame pacing was enabled.

Scougar · 6 May 2015 at 02:39

After trying for a while... at present (and to be fair I don't know what I'm doing) dual graphics in Planetside 2 is a really bad experience. It just isn't fluid. It actually makes playing the game extremely difficult and not enjoyable. I think the crossfire just isn't working as expected in this game.

I tried out the single 7750 2GB ddr3 overclocked to 960mhz/870 and it was a far more satisfying experience, the FPS was much more steady and the game was relatively fluid. Will try just the APU tomorrow maybe.

Meaker · 6 May 2015 at 02:46

Scougar said:
After trying for a while... at present (and to be fair I don't know what I'm doing) dual graphics in Planetside 2 is a really bad experience. It just isn't fluid. It actually makes playing the game extremely difficult and not enjoyable. I think the crossfire just isn't working as expected in this game.

I tried out the single 7750 2GB ddr3 overclocked to 960mhz/870 and it was a far more satisfying experience, the FPS was much more steady and the game was relatively fluid. Will try just the APU tomorrow maybe.

This is pretty normal to be fair for hybrid crossfire, maybe with DX12 it could be done better.

Scougar · 6 May 2015 at 03:20

Makes you wonder what the hell is the point of it, if it's unable to be reasonably playable? The FPS is fine, just totally stuttery. Turning off frame pacing makes it worse, but even with it on it's bad. I have my APU hard set to 4400Mhz, so it isn't the APU clock that is causing it.