Topic: Curious about peoples clocks and flags for caymans (HD69xx) cards (Read 5231 times)

For those of you with underwelming results with 6970's check your voltages and clock speeds.  If you are overclocking (even by a very little bit) bump your voltage by 5%.. Or if your not ok with overvolting clock back down to factory (or slightly lower).

My Powercolor was out of the box OCed to 940mhz.. But for Hashing I was getting 320s until I overvolted it by 5% then I jumped into the 400s (411 right now).  I also was able to get into the 380s by downclocking back to factory 880 with stock voltage.

These GPUs are very speed/voltage sensitive.. If your results are to far out of the "norm" then gently playing with voltage and speed can help (going down in some cases can actually make you faster!).

Oh and just as a CYA: Be careful, monitor temps like a hawk, and I am not responsible if you blow up your card, this stuff is easy to do right, and just as easy to do wrong.. Doing it wrong can damage the card so be careful and make sure you have the needed cooling.

~Hands
(here is the ubiquitous "donate" wallet ID 13d46unynPiuspsND1fC3kuPeb8szgWv4T)

I've got some questions about the 6970 as well.  I've tried recommended settings from several people, most recently those discussed here:  http://forum.bitcoin.org/index.php?topic=13809.0, all to little effect.  They report rates of 400+ and I have yet to break the 350 barrier.  I'm obviously missing something but have not idea what that might be.   Anybody have any suggestions?

Yeah... I suppose i could bump the aggression up... but it would have to beat Poc by a decent amount to be worth the loss of responsiveness on my system... hmmm... and you say to try and set fastloop off? Interesting... I need to find a good source for what exactly these parameters are.

Try playing with the AGGRESSION value and add FASTLOOP=false for the higher levels - those might help.

I think I am already running that one..  isn't GUIMiner V2011-06-09 the latest?

And I believe with phoenix the flags are "-k phatk VECTORS BFI_INT" or something along those lines... I tried it and was hashing a bit worse then default Poc... So I'll have to dig into more settings, or try command line phoenix with phatk.

Just tried it again:

just -k phatk = 250MHash/s

add VECTORS = 254.5MHash/s ish

add BFI_INT =  251.x MHash/s

Stock Poc no flags = 305-314 MHash/s

In many cases if your overclock puts you in a stability position where your voltage selected isn't enough to stabilize the GPU, then you actually lose speed due to lack of stability. often you will find this occurs just before you start to induce crashing if you keep turningthe speed up w/o a change in voltage... Also, if voltage and speed are at a given setting, and 'should work' then you need to check heat and see if that is an issue. Heat as well will destabilize, and give an environment which would lower your scores as the card tries to cope.. (think VRM heat and lack of stable power, or chip heat - more rare)

Two other cases to consider - power throttling and memory speed throttling

a: power throttling occurs because 69xx cards can have there TDP limited, in this case the power is being artificially limited by more then just a voltage setting, this was introduced so that you wouldn't burn your card up in things like Furmark.. it simply limits the cards overall power draw at some level.. turn this up, and it may stabilize, and give expected results. 
(Can be found in CCC, there will be a setting labeled Power Control Settings with a slider between -20 and +20.... try adjusting that to the right... Be careful. Especially if for example its heat thats got you down, this won't help.)

b. memory bus speed throttling.. the 69xx cards have avery fast ddr5 memory bus, however it to can have issues when overclocked (less a concern with mining as the mem bus doesn't even need to be stock i know) however, when card starts to detect errors, it will actually slow the mem bus down effectively to bring it out of an error generating state, rather then passing errors on... So in away it will use speed to ECC...


Hope that helps you.


If i help.. donate if you like  1Knz5HnWEZ9trngjfZze4dEHergCTQJ15w

Guys go give the new GUIMiner with Phoenix and Phatk a try.. as I understand it the standard OpenCL app for GUIMiner (the name illudes me right now) doesn't play nice with 2.4 but phatk does.. go read up on the Phoenix miner to know what flags to use (they are completely different).

I get 325 on my 6950s and 411 with my 6970s (both slightly OCed) with Phoenix and phatk

~Hands
(here is the ubiquitous "donate" wallet ID 13d46unynPiuspsND1fC3kuPeb8szgWv4T)

 i got 6970 and run with 365Mhash/s and no oc but when i overclocked it , the hash turn down to 310 Mhash/s . anyone can explain it?

Just figured I'd add it again.. but when I put in the -v, I drop by about 12-15% I go from 314ish to 274 ish... hmm.. I'll keep digging. perhaps its the miner I am using.

Which miner and kernel do you use? what's your hash rate?

thx

on my 6950 I cannot see any difference between -w 64 and -w 128, but using -v increases hashrate by about 5%

Interesting... Do you remember your scores before and after? also, i am running win 7 so i assume I may have a lower MHash/s then you will... However, one thing I hadn't found so far, is where my version of ATI SDK would be found. I couldn't find it in the Catalyst properties, and so i assume since I don't seem to glean the benefits of some of the various flags, that i am running 2.4... Also, I have heard that dfferent miners can yield better results for me, but so far, no kernel or miner I have tried through GUIMiner has been better then no flags and default Poc...

Can anyone chime in with some better windows results then 310-315Mhashs/s?

Willing to try a different miner if need be to achieve.

Also: does lowering memory clocks achieve anything other then dropping power consumption slightly?

Thanks All.

It's strange to me but "-v -w128" started to help on my 6950s after the memory was downclocked a bit. Before then, '-v' definitely hurt and '-w128' was a wash.

When running two processes and adding the reported rates, the total seems a little higher, and aticonfig --odgc more consistently shows 99% GPU utilization.

"-f1" seems to help a tiny bit, or at least make the samples over time less jumpy.

Using poclbm on 64-bit linux with ATI driver 11.5 and APP SDK 2.4.

I tried that... and it doesn't.

It does on my HD 5850... but HD5xxx hardware uses a 5 wide execution unit, whereas Cayman (HD69xx) uses a 4 wide execution unit... I found it actually dropped me by about 40MHashes/s with GUIMiner and Poclbm...

So i am thinking that the boost i saw on my HD5850 was related to the wider architecture that AMD dropped with its 69xx series... Thanks though, that's one of the reasons i posted here... That and to give newbies something to post about for 5 hours Consider it a captive audience :p

Have you tried it on your cards? Do you have a 69xx?

Thanks.

"-v -w128" should net you a nice little boost.

Hey there,

Curious about the miner you use, clocks on your card, and which flags you use... looking to see if i have maxed my Cayman out:


XFX 6950 1GB running: GUIminer v2011-06-09 w/default poclbm / 840 Mhz GPU / no extra flags -- 305-315 MHashes / s

Anyone else out there? I should be receiving my 2nd 6950 in a few days so better settings (if available) x 2 then.