So, I decided to slap in my old 5770 (flashed to 6770) along side my 2 7970's and after some mucking about having to hook up external power to one of the powered risers hosting one of the 7970's, I have the 7970's hashing away at full speed. A voltage drop caused the primary card to slow to a crawl, 2 cards with no power to the risers is fine but add another card in and I definitely needed more power than the board was giving...
Anyway, getting off track a little.. I'm using the latest version of CGMiner (3.2.2) and whilst tuning clocks on the 5770, I noticed that CGMiner was reporting a different temperature reading than what HWiNFO was reporting, a discrepancy of 12C! The GPU core seems hotter than what CGMiner is reporting. CGMiner is reporting correctly for the 2 7970's but not for the 5770... I'm wondering if this is a bug?
See for yourself. Check out the 5770 (marked out in a
RED box) and compare it to the value reported for the Thermal Diode in HWiNFO... Disregard the fan speed, I dropped it to a low enough value so I could compare the temperatures easily. I have the fan on 85% atm and the temperature in HWiNFO dropped to 73C but there was no drop in CGMiner.