GPU Boost on Radeon 7870 XT

[Senti]

Hi.

The card I have is Radeon 7870 XT by Club 3D http://www.club-3d.com/index.php/products/reader.en/product/radeon-hd-7870XT-jokercard.1398.html

I tried mining with it but it only gets around 418MH/s due to low gpu clock speed 925MHz. It's supposed to go to 975 using this GPU Boost feature but no matter what I do (using amd overdrive settings, using --gpu-engine in cgminer) it's actual clock stays at 925 when mining. Is there a way to disable GPU Boost thus forcing clock values set by myself? Or somehow trigger it to turn it on when mining?

My guess is it increases clock frequency only in 3D mode and that's why it doesn't do it when mining as it should when GPU is under full load.
I will run some game in a minute and try to log clock values to see if they actually rise during 3d mode.

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[jerethdaminer]

hrrm i have a 7970 and only get 100mhash more so i may need to look into that

[spixel]

hrrm i have a 7970 and only get 100mhash more so i may need to look into that

7870 boost is very close to 7950 so 100 more with a 7970 doesn't seem too off.

[Senti]

So I played Diablo 3 for a minute and log file made by gpu-z shows me that clock values jump from (idle?) 300MHz to 925 (default not overclocked) to 980 (value to which the clock changes when gpu boost kicks in, I set in amd overdrive) -> but this is rather rare, so it probably kicks in only when needed too, when fps count drops.

Still don't know how to force higher clock values than 925MHz when mining. I would like to try to turn it up to something like 1100MHz or even higher cause temperatures when mining when fan is set to 70-80% stay way below 60 degrees C

[jerethdaminer]

turn on overdrive in vision center, and work from there i just underclocked mine a bit be sure to read up on it

[Senti]

As I've said before I already did that - enabled Graphics OverDrive. No matter what value I set in "High Performance GPU clock settings" the actual clock value when I'm mining stays at the default 925MHz because this setting only affects GPU Boost mode (at least I think so) which doesn't kick in when mining.

[jerethdaminer]

strange im using gui mner and have no idea how to alter or see what its doing . but gpuz and all other programs shhop my gpu running what i told it to so im hoping the miner isnt fiddling things

[Senti]

I will try to run guiminer tomorrow (right now I'm getting some strange error with it "ValueError: need more than 1 value to unpack") but I doubt it will change anything. I'd really like to get it working at full speed.  I've seen couple of tests of this card and it overclocks really well >1200MHz on core http://www.techpowerup.com/reviews/Club_3D/HD_7870_jokerCard_Tahiti_LE/31.html

Also there are two 7870XT cards listed here, both around 500MH/s and overclocked to 1200MHz https://en.bitcoin.it/wiki/Mining_hardware_comparison

Maybe there is some parameter in cgminer that fools the card driver into "thinking" it's in 3d mode and can actually achieve anything higher than 925MHz.

But now I need to get some sleep

[Senti]

Ok, when I moved "power control settings" slider all the way up to 20% in AMD Vision it finally overclocks, (I didn't try to use this slider before cause I've been trying to increase core clock by small values like +10MHz at first and I didn't think it was necessary to give it higher power) I set it to 1160 and am getting steady 480-490MH/s, sometimes it shows even 520 for a second or two. When I set it to 1200 I started getting some visual glitches, so I think 1160 is enough. Now I've got another question, why can't I lower memory clocks to value that is more than 150MHz below core clock? Right now the lowest I can set it to is 1010MHz and if I go lower than this it sets it to the default 1500MHz.


EDIT: I used MSI Afterburner and managed to lower my mem clock all the way down to 300MHz (lower than that caused glitches) aaand I have steady 520MH/s now @1160 clock Probably higher mem clock used some of that +voltage I set earlier and my gpu usage jumped from 100% to 65% back and forth which cause also clock jumping from 1160 to default 925 and back. Now everything's steady 1160 clock 300 mem, 100% gpu usage and 520MH/s

[rnaodm]

Hi senti, I just got a 7870xt, currently at 1150core/1200mem running about 490Mhash/s and 20% power control in CCC.

I'd like to know what temps your getting, Im afraid my 73c(100% fan speed) might be a bit high and I don't want to burn out my brand new card.

[greaterninja]

i got two of mine to 1200-1215 mhz gpu,

-8% voltage  / power

fan 90-100%


72-78c

they produce 498-515mh/s

[GenTarkin]

I got 2 powercolor 7870xt's .. very interesting.
Their asic quality is 12% different from each other.
One is around 74%, the other is 62%

The one thats 62% I have to keep at 1115mhz @ 1.131v to be stable
The 74% is so far, at 1140mhz @ 1.088v

Quite a large difference and Im still testing.

[Miracek]

I have 2 Sapphire 7870xt's running 1150 core and 1001 mem getting over 500 Mhash each;