PSU Issue? Miner locking up.

[Cablesaurus]

I'm having an odd issue on my Win7 64 4-card miner.
The box has 3 5870's and 1 5850.
I had been using it with a Corsair 850tx psu.

A few days ago I had a few lockups... I tuned the 5850 down 25mhz and that seemed to help, until last night, I've had 3 lockups since last evening.

I tuned each of the 4 cards back down 25mhz, however the machine still locked up in about an hour.

No idea what could be the root of this, could it be a PSU issue or something else entirely?

[trentzb]

What MB/CPU/RAM are you using? What core/mem/vddc are your GPUs set to?

You may be running up against PSU limits. I don't trust the https://en.bitcoin.it/wiki/Mining_Hardware_Comparison for power consumption any longer after I measured 256W being pulled from a 5850 on just the two 6-pin PCIe connectors. Granted I had a reasonable OC.

[Basiley]

for 4x5870 setup you need something like 1200W PSU, imo.
but thats depend 12V bus PSU caps.

[chungenhung]

definitely PSU or maybe the outlet simply can't supply enough power.

[zimpixa]

With 5850 at 985/300 1.2V its taking 200W more from idle to 100% usage (measured from socket). So your 5870 can take up to 250W I guess. PSU for sure. It was working, cuz U were some time above the limit, which your PSU could handle, but its ability was downgrading much faster.