Quote from: Starscream on February 20, 2014, 11:06:45 AM

First thing first, add the following to the start of your batch file:
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1

Those would be for windows, I use linux; and I already have the same commands albeit correct for linux in all of my startup scripts.

Quote from: Starscream

Now, you need to understand that the number of threads you should be using is dictated by your card (not all cards can run well with 1 thread same as not all cards can run well with 2 threads) so find out which is best for your card (by finding out I mean try it out for yourself).

These rigs are rigs that I have countless hours of tweaking on normal scrypt and have determined that 2 GPU threads is by far the best. I gain about 30% going from 1 to 2.

Quote from: Starscream

Next, the number of TC (thread-concurrency) in your settings is capped by how many threads you're using and by how much RAM you got in your system (to determine how much TC you need to set: Shaders*n+1 (this formula will give you, generally speaking, the best resaults), n can and will be any number you choose but is subject to the limits of your cards/settings, although YMMV).

Again, countless hours of tweaking on these rigs and I have identified my optimal TC, but this is adaptive n-scrypt mining so the normal rules don't necessarily apply.

Quote from: Starscream

So, for your OP, if with 1 thread you see low KH/s than you should change your TC.

If with 2 threads you still get error -5 (after adding the setx commands) than you should lower your TC. A common TC value that works well with -g 2 is 8193.

I tried 8193 on a whim, and same thing. I really appreciate all of your help, but I think you're perhaps barking up the wrong tree. My thoughts are that this may be an adaptive n-scrypt specific issue, or perhaps a bug in vertminer.