GPU 2, GpuMiner dk2an0 failed -4
Managed to get rid of it setting the virtual memory to...
50 GB ?!?!?!?!

What the hell are you doing with 50Gb ? Opening a a porn site ?

Some features still don't work and crashes the rig (GPU clock and setting the -h value).
Nice speed increase 10-20%

The same amount of memory that is allocated in the gpu memory and used for computations must be duplicated in virtual memory.
So for multi-gpu rigs it is huge.
-h option works well, check what you are doing ...
Around 52 Gb then.. Got it.
-h option is not working on my rigs. Tried 992 and 1000 on two of them.
Checked again.
It apeares that the rig didn't crash after all but it slowed down 99.9% and there wasn't anything moving. Minutes later one line with the temperature appeared on the miner window.
There are no other parameters. Just the pool address, the user, the password and the -h 992. So I could not be doing anything wrong.