Bitcoin Forum

I just compiled up a copy of cgminer to run on my Mac Pro (10.7.5) on my AMD5770.
I got it to compile, and it seems to run without issue. Well except one issue, speed. I've tried all sorts of settings, copying settings others use, but no matter what, I'm only getting about 3Kh/s. Three. Other people using 5770s seem to get around 180-200Kh/sec. I, am getting three. I can run Diablo and get 175mh/sec doing bitcoin. That may not be the fastest time, but its well in the neighborhood of where it should be. What is going on this this litecoin stuff?

http://s17.postimg.org/zfo5xkv5r/Screen_Shot_2013_04_22_at_1_10_06_AM.png

Overclock it to: 912GPU, 1250MEM with 1.2v (it can run on 1.125 provided your pc is not used, what so ever)
Following settings: -w 256 -v 1 --thread-concurrency 3200 --intensity 18 -g 1 --scrypt

Should give you somewhat 200kh/s.

Have you tried any other miners? I know for me litecoins mine way slower than they should on cgminer.

Having the intensity that high locks up my machine. Leaving the intensity setting out of your options, I get the same 3.2kh/sec or so.

I haven't found any other GPU litecoin miners, at least none that will run on OS X.
The 180kh/sec number is what other people get with cgminer, mining litecoins. I can't imagine what would be causing mine to suddenly run absurdly slow.

While I was working on this, cgminer 3.0.0 was released. I got it compiled, both with and without scrypt support. As a bitcoin miner, it was getting upwards of 160MH/sec, without doing any dialing in.

YET it's still getting right around 3kh/sec doing litecoin. What is this all about? It should be 65x faster than this, give or take.

Occasionally, when I start up cgminer on my pc with a flashed 6950 it will hover around 20-30 kH/s for a minute or two before heading up to 400-450 kH/s. I don't know why and it only does it every now and then.

Have you let it run at least 5 minutes?  Maybe it will pick up speed after a bit.

There's a good guide on here about setting up your card too, although bad setup shouldn't cause that bad a problem.

I'm pretty sure I have let it run for a while. I'll try again and post back if it picks up speed. But it's been slow 100% of the time. The best speed I got was 4.5kh/sec using -w 128, anything higher or lower and it goes back to ~3

Just did a 20 minute test, got up to about 5.1kh/sec. I also quit my CPU miner while I did this, just in case the CPU load was somehow slowing things down. 5.1, that's almost as fast as one of the eight CPU cores my machine has.

What is most baffling, is that other OpenCL things run fine. Bitcoins mine fine. Collatz Conjecture via BOINC runs really great on this thing. Something about litecoins, she no likey. And my next computer is going to have intel HD 4000 graphics :(

So I have been able to get my speed up a little bit. Well a lot actually. Putting my intensity at a max of 16, I was able to get up to about 69kh/sec
Any higher intensity, and everything just locks up. Thats not a great number, it's much slower than what's reported for a 5770 on the litecoin hardware comparison page. But at least that, plus my CPU hashing, gets me into triple-digit land. Not ideal but, it's something.

Here's my config options for 3 flashed 6950s and one unflashed 6950, maybe it will help:

--scrypt -o pool:port -u user1 -p password --thread-concurrency 6144,6144,6144,5920 -I 19 -g 1 -w 256 --gpu-platform 0 --auto-fan --auto-gpu --gpu-engine 600-920,600-920,600-885,600-885 --temp-target 77 -s 5 --gpu-vddc 1.1 --api-listen --api-allow W:127.0.0.1:4028

Have you tried different pools?  I generally have 3 in my config because I can.

I've gotten the exact same speed whether in a pool or mining solo. I would ideally like to mine solo if I can whip up a good rig.