Bitcoin Forum

Hey everyone, I'm a "newbie", so I can't post this in the DiabloMiner thread where this post belongs, so here goes...

Anyways, here's my system specs:

iMac 2011 (27")
3.4ghz i7 2600, 12GB RAM, 6970M 2GB.
Running version 10.6.8 of Mac OS X.

Here's the DiabloMiner start line (info for mining.bitcoin.cz replaced with "REMOVED"):
./DiabloMiner-OSX.sh -u REMOVED.REMOVED -p REMOVED -o api2.bitcoin.cz -r 8332

Here's what it spits out (all fine AFAIK):
[7/18/11 2:11:57 PM] Started                                                
[7/18/11 2:11:57 PM] Connecting to: http://api2.bitcoin.cz:8332/            
[7/18/11 2:11:57 PM] Using Apple OpenCL 1.0 (Jan  2 2011 18:00:11)          
[7/18/11 2:12:00 PM] Added ATI Radeon HD 6970M (#1) (10 CU, local work size of 256)

Here's what happens after 1 minute or so of running:
[7/18/11 2:14:08 PM] ERROR: Invalid solution 1 from ATI Radeon HD 6970M (#1), possible driver or hardware issue

That error is spammed ~50 times a second, until I quit DiabloMiner.

Anyone have any help? I used to mine at a paltry 10 mhash/sec with my old computer, and I was excited to start mining again with this new card/computer, but the errors mean that mining just won't work until I figure out a fix :(.

Thanks anyways!

I would not recommend mining in OS X. I've got a 21.5'' iMac and I mine in Windows with poclbm. Gives much higher hashrate and no errors.

The problem is that OpenCL in OSX is ... not very good. I get the same error on a current DiabloMiner and any other GPU miners based on the phatk kernel. From what I see, the OSX OpenCL-compiler seems to optimize the entire kernel away, so it runs in zero time but zero results as well.

You can try the Mac app solution from this thread: http://forum.bitcoin.org/index.php?topic=8994.0

This is based on an earlier DiabloMiner with a non-phatk-Kernel, it works nicely for me, but won't give maximum hash rates compared to Windows or Linux mining.

So, you may either switch your OS for mining, or hope that the OpenCL in Lion will fix the issue...

This will likely happen. In another thread some user reported a significant increase in performance with Lion.

THANKS for that link!

Getting 100 mhashs/sec from my card with that, although it lags the computer quite a bit, so I'll need to take a look at limiting it, but other than that, it's GREAT! 10x the speed of my previous card! I'll admit it, I didn't have great expectations for this card, but it's much faster than I thought.

Now to set it up on a schedule, and to increase fan speeds to reduce heat...

I'll most likely not mine much with it, as it's a laptop GPU, in a iMac case, which means that heat and wear and tear could be problems, but this is good enough for me.

I can't move to Lion until several apps I use update for it, as they are critical ones that I kind of need, so I'll stick with SL for now.

My pleasure.

Regarding performance, try playing with loops and worksize (-z and -w), you can get a bit more out of it if you manage to find the optimum settings for your GPU. Check the the wiki and forum for that.

Also, regarding responsiveness, try adjusting the FPS (-f), at something like 60 or 120 you may loose a few MHashes but your UI experience will be smoother.

Some people also disable Quartz Extreme.  That will make the window server render using the CPU instead of the GPU.   That way you can regain good desktop responsiveness without losing MH/s.   I haven't tried this myself but it should work.  Since you are on an iMac, you should also get SMC fan control and boost your fan speed to keep the system cool.   

I decided to just mine in Windows after having performance and heat issues in OSX and this is on a Mac Pro.  The tools for monitoring and cooling the GPU are just better on Windows and Linux and Apple's OpenCL is seriously lacking.   If you can use bootcamp to mine in Windows or Linux for when you don't need OSX, your computer will thank you.   You could get Linux or even Windows to boot off a USB key,  Bitcoin mining requires almost no HDD access.