I've been running ~3 hours stable with:
__CORE_OVERCLOCK=200
MEMORY_OVERCLOCK=900
-pl 105
How much further can/should I push this with only 105W power? I'm stuck with 2 cards per PCI-E cable until next week when I get a shipment of new cables.
You can try upping the mc further; it depends on the specific card when it will start having problems. When mining anything ethash I usually bump the memory up slowly until I have a crash then backoff to the previous setting. If a crash happens again, I backoff again.
I bumped up the mc last night before going to bed. It's been running stably since then.
__CORE_OVERCLOCK=200
MEMORY_OVERCLOCK=1100
-pl 105
Thanks again for hashes, very generous.
If it is still stable; I would try:
__CORE_OVERCLOCK=200
MEMORY_OVERCLOCK=1200
and see how it goes.