I can't seem to get my asus 280x 6card system stable on vertminer. All 3 of my rigs run Bamt 1.3. This is my only 6card configuration
This config achieves 375kh/s but only lasts for ~10mins then system freezes. I've tried default voltage for all six cards. Same outcome. Power is not the issue 1200w+850w for this system
Vertminer 0.5.3
Updated app sdk to 2.9 and upped coreclock to 1100 pumps out 393kh/s but crashes same as before. My other 2 systems run 3 gigabyte 280x's and have no problem running 8191,8192,8193 TC with 1500mem. One 3card has 2GB's ram and the other has 4GB's ram. Both are very old dual core systems.

6card rig is brand new hardware 8GB's 6core. I've tried newer catalyst drivers, same outcome +lower hashrate. Also tried vertminer 0.5.2 and 0.5.4pre2 = lower hashrate+crash. Next on my list is to try 64bit xbuntu.
I'm pulling my hair out getting to the bottom of this one. I can drop the memory down to 1250Mhz but the wu is under 300 per card unacceptable. For now I'm stuck mining doge or whatever for the 6cards. Any ideas from anyone? Anybody with 6card rigs having issues with vertminer?

Edit: Turns out gpu0 was the culprit. Lowered gpu0's memclock to 1250 and 360kh. WU:330
I kept getting too many hw errors and the occasional dead gpu so the other 5 cards are running 1375 memclock and achieve 372kh. WU:340

I still get a few hw errors but it's only 1 or 2 gpus and is well below 1%

Thank you papagalka666, I just assumed these cards would all be around the same settings in relation to each other with vertccoin. That's how they are with regular scrypt