xfx 7950 core clock reverts to half during games

[Singular1ty]

Hi all, I recently bought an XFX R7950 Black Edition. When I play games, the clock speed goes from 900Mhz down to 500Mhz, and my framerate drops. However, if I disable 2 of my 3 screens, the clock speed stays at 900Mhz, but the framerate isn't what I have seen others get with the same card, most noticabley on Arma2/DayZ. I should be able to play that game with everything at max at a very playable framerate, but I can't.

My specs are as follows:

CPU: Amd x6 1055t, no overclock
MB: Gigabyte GA-78LMT-S2P
RAM: 4GB Kingston
Disk/Optical Drives: 128GB Crucial M4 SSD, 512GB Western Digital HDD, Samsung BluRay ROM
PSU: CoolerMaster Silent Pro M 500w 80+ Bronze
GPU: XFX Radeon R7950 BE
Various case fans

GPU temps are always under 70c, and voltages are stable at around 1.169v.

It might just be that my 500w power supply just isn't powerful enough, and all I have to do is upgrade, since XFX recommend a 650w psu for this card.

This also happens soon after a restart, so can't be Adobe Flash getting in the way as I've seen with 7950's.

Any thoughts on this would be appreciated, thanks.

 

[Drangueos]

500W is more than enough for 1 7950.
try to set the power limit to 20% and see if it still dropping the clock.
which drivers are you using?
remove all drivers and install the last ones

 

[sockky]

I had the same thing before, uninstalling the drivers and reinstalling them fixed this for me.

 

[Singular1ty]

500W is more than enough for 1 7950.
try to set the power limit to 20% and see if it still dropping the clock.
which drivers are you using?
remove all drivers and install the last ones

Thanks both for the replies.

What do you mean by setting the power limit? I've got "power control settings" in the CCC under AMD Overdrive, can go from -20% to +20%.

I'm using the latest stable, 13.4, Windows 7 x64.

I uninstalled my driver, reinstalled, but still get the drop. Although, after restarting after installing the driver again, my pc would display a black screen and just the cursor. I'd reset the machine after waiting a few minutes, if that matters.

 

[ArchAndroid]

Catalyst Control Centre

Performance > AMD Overdrive > Power control settings

Slide controller to 20. It should display 20% next to the slider.

 

[Singular1ty]

Catalyst Control Centre

Performance > AMD Overdrive > Power control settings

Slide controller to 20. It should display 20% next to the slider.

The GPU clock never dropped below 900Mhz. Temps did increase to 74c though. What does this show me/tell us?

Thanks .

 

[fishingcat]

The increased power limit means the card will get more voltage under load, allowing it to maintain its 900MHz clock but generating more heat in the process.

74 degrees certainly isn't anything to worry about though, and at least now you're not throttling down.

You really shouldn't have been experiencing throttling at stock clocks though. My card didn't start doing that until around 1200MHz.

 

[Thracks]

I wonder if the amperage coming from the PSU was low enough to trigger PowerTune's protective clock throttling.

 

[Davedree]

The increased power limit means the card will get more voltage under load, allowing it to maintain its 900MHz clock but generating more heat in the process.

74 degrees certainly isn't anything to worry about though, and at least now you're not throttling down.

You really shouldn't have been experiencing throttling at stock clocks though. My card didn't start doing that until around 1200MHz.

Not quite right but nearly right, the power limit slider allows the card to work at a higher tdp than the standard limits before it throttles the frequency down.
A higher power limit doesnt increase voltage/current draw but instead increases the threshold to when max tdp limit is hit. You are correct though it will increase temp as the card maintains its full potential for longer instead of throttling.

to the op, 1.18v is high for 900mhz, get that card clocked its begging for 1050/1150 mhz on the core, or at least undervolt to 1.04/ 1.06v for 900mhz then youd see temps in the 60's.

my 7950 was running hot and the pc would hard crash, i upgraded the psu and temp and crashing issue was solved.

 

[Singular1ty]

Hmm thanks. If I overclock to 1050+ though, will it draw more power and end up throttling again or even crash? Would upgrading the power supply help at all for me?

 

[Drangueos]

Hmm thanks. If I overclock to 1050+ though, will it draw more power and end up throttling again or even crash? Would upgrading the power supply help at all for me?

like I already said... your psu is more than enough for 1x 7950... your computer will use less than 400W in total

 

[Davedree]

Hmm thanks. If I overclock to 1050+ though, will it draw more power and end up throttling again or even crash? Would upgrading the power supply help at all for me?

How the v-core is setup on your gpu at the moment, is too high and very inefficient for the clockspeed its running at. It's drawing more voltage and current than needed even though the clock is 900mhz, so it runs hotter than it needs to and hits thermal throttling quicker than if it ran at a lower v-core .
If you increased to 1050 then the card won't use any more voltage than it would at 900mhz. It won't draw anymore power unless you increase the voltage manually.

If you read about the 7850's they are artificially underclocked to provide a bigger performance gap between it and a 7870. But a 7850 usually can overclock from 800/860mhz all the way upto 1050 without an increase in voltage. (dependent on the manufacturers stock v-core).

Same applies to your 7950 there should be another 150/200mhz potential with ease.

I

 

[Singular1ty]

Ah I see, yeah I'll read into it some time, thanks. Put it up to 1050Mhz and all is fine, may nudge the clock speed up more and the memory clock. What temp should I not go higher than, 85 or so? And, with the overclock, should I keep the power at 20%?
Also I just want to be sure that my psu is not going to cause me any issues, I have read benchmarks showing this cpu taking 200w+ under load and the 7950 taking 300w+, so I don't want it to be a problem later. I do play eyefinity sometimes, if that's going to cause problems?

Thanks.