Litecoin mining 10 times slower than a couple of days ago

Question

I have a 5850, and have been mining with it for about a week.

With GuiMiner I can mine bitcoins at about 275Mhash/s. This has not changed.

A couple of days ago I setup Litecoin mining and it was working at about 350Khash/s, which at the time was about the same profit as Bitcoin.

But now when I mine litecoins I'm only getting 35 khash/s.

I'm getting the same speed with CGMiner or Reaper. I just started the exact same setup I had last week and I'm getting the crappy result. I've been messing with settings and config, but no change.

I have rebooted, no change. I can change back to Bitcoins anytime and get 275Mhash/s with CGMiner, but when I change CGMiner to Scrypt mining it drops to 10% what it should be getting.

I can't think of anything that would cause this. Any thoughts?

Scrypt CGMiner mining: http://puu.sh/2d7Mp

Bitcoin CGMiner mining: http://puu.sh/2d7NW

Current CGminer command: cgminer --scrypt -o x -u Liquid5n0w.1 -p x --intensity 12 --worksize 256 -g 1 --lookup-gap 2 --thread-concurrency 7200 --fix-protocol

Answer 1

I have found the cause:

I had GUIMiner to start on startup, and even though I was stopping it before I'd try to use CGMiner or Reaper, it did something to the drivers and would prevent LTC mining from starting correctly.

If you have a similar problem to this, try to disable GUIMiner on startup.

Answer 2

This has happened to me several times, and I have always been able to resolve this by deleting the .conf file (for cgminer this is /cgminer.conf)

Since you have already been mining at a nice rate, I do not think this is an issue with the command you are passing, however others with similar problems might want to try the following tutorial:

https://bitcointalk.org/index.php?topic=97143.msg1069730#msg1069730

Hope this helps!

Answer 3

Try what I sent to you with the modded version of cgminer and see how you get on with that. If you are mining with .conf file grab the default one from cgminer and relapse it and use and create .bat files if you know how to do that and progress from their.

Other than that try removing all drivers and starting fresh. If that does not work with custom modded cgminer then you could of done something to the card, could be anything. the other option you have is to try the card on another system.