I've had a v1 blade for about six or seven weeks now. It started out with four xxxx, but I didn't feel like sending it in for replacement as I'd be losing valuable lower-difficulty mining time.
As of the last week, however, it started getting all xxx's until I did a hard reset. I lowered the voltage down to 1.15 and it seems more stable now, but I can never get above around 7500 MH/s and 16-17% efficiency.
Anyone have any ideas?
At that voltage I presume you're overclocking? Make sure you're checking voltage properly, with the ground probe directly on the power plug of the PCB and the other probe on the VRM output. Next, I'd check the output of all the VRM's to see what they are. Most of my overclocked blades worked best when set to 1.185. Sometimes they could go lower but not usually.
If you aren't overclocking I'd suggest 1.045-1.07.
Make sure your cooling is adequate also. I'm using one fan per blade, each fan is at least 105cfm, some are 125. The fan is oriented beneath the blade blowing up across both sides of the blade. This keeps them pretty much cold to the touch.
As to the hashing, my effective hash rate for most OC'd blades is above that. I'm presuming cooling and voltage inconsistancies are causing you issues. Also, I would suggest BFG proxy if you aren't already using it.