Bitcoin Forum

What you see before you is as follows:

GPU 0: phoenix.exe -u http://|||||||||||||||||||@pit.deepbit.net:8332 PLATFORM=0 DEVICE=0 -k phatk BFI_INT VECTORS AGGRESSION=12

GPU 1: poclbm.exe --user=||||||||||| --pass=||||| -o pit.deepbit.net -p 8332 --device=1 --platform=0 --verbose  -v --worksize=192 --frames=1 -a3 -a 3

Both GPU cores OC to 965 MHz.

I'm using the optimised phatk kernel, that supposedly drops another 10 MH/s on top. Poclbm is killing it. What am I doing wrong?

http://i53.tinypic.com/vnfa69.jpg

Edit - Both cores at 99% and 77°C.

try a better program.

If you don't mind mining at the BitMinter pool (and get 5% extra pay while promotion lasts), you could try the BitMinter miner. It's the fastest miner on 6990 right now.

If you try this miner and do a speed comparison, especially on multi-GPU systems, hit the little button in the lower right for performance mode. Otherwise all the screen updates can cause a noticable performance hit.

Why is it that i am seeing that the faster miner i.e 446 mhash/s has waay less shares than the slower miner?

I've been experimenting with poclbm flags with #1, it's been on and off all day.

@BitMinter no thanks I don't feel like having my wallet stolen today.

@xcooling That's what I'm trying to do. So far poclbm is the best.

add a fastloop=false and worksize=192 to the phoenix to see if it makes a difference.

And don't complain - go with the one that's fastest. If poclbm is better, just use that then.

I don't know where you get this idea from, but my software doesn't steal wallets.

You may want to try a miner that can run several GPUs from the same miner instance, though. I have noticed sometimes if I have several OpenCL programs running it can affect performance, even if only one of them is actively using the GPU.

If you think my miner is "the devil", then I'd recommend trying DiabloMiner. That's the real devil  ;D But seriously, that's another miner that can run multiple GPUs from the same miner instance, and perhaps help avoid the problems you are experiencing.

it seems to me like phatk on phoenix is what everyone with the best scores on the mining hardware comparison wiki page use but that doesn't mean a thing.  I tried many, many configurations and got within about 5 MH/s but POCLBM was still faster.  Maybe it works better on some cards but it would appear that for my 5830, everyone on the wiki with higher OCing speeds than me are basically using the wrong kernel and that's all there is to it :P

GPU 0 is also busy drawing your Windows display. This cuts off some MHash/sec.

If you want a fair and accurate comparison, test your miners on GPU 1 only.

To speed up GPU 0 some more, turn off Windows Aero completely.

I've had better luck with phoenix/phatk, but I've also found that it is more tricky to tune. BTW, if both those GPUs have been running for the same length of time and on the same settings, notice that the one hashing at the lower rate has actually submitted more shares. IMO, you have to fine tune your cards for submission rate rather than MHps, because after a certain point, higher hash rate doesn't necessarily correlate with a higher share submission rate. But you get paid for your share submission rate, not your hash rate.

i'm pretty sure the WORKSIZE is suppose to be 128 not 192 for 6 series cards.

Phatk was lower on my 6950's for some reason too.

BTW, if you have 6XXX series, the work size should be 256.  You'll get a slight boost.  Use 128 on 5XXX series cards

Cheers

Actually I find 128 better on my 6990 and 256 better on my 5870.  ::)

Interesting.  I get about 2 Mh/s better with the 256.  I might give it another try. 

is it faster for 5870?

You can try it and see.

I think DiabloMiner and modified-Phoenix with modified-phatk (from another thread in the forums) are still a little faster on those cards. I'll have to close that gap when I have more time.