What was the aux voltage before the cleaning? Do you believe it is due to the memory frequency going down from 1500 to 1200? Did you see the difference in power in/out?
aux -100mV adds another 15W of powersaving, from 540 to 525W. Memory downclock savings are minimal, hard to see at the wall.
No difference in power in/out. 1125/1200 is the ratio where memory controller load is 96-97%.
I thought the IC power consumption is linearly proportional to the circuit frequency. Why the drop from 1500 to 1200 MHz has not effect?
I thought so too but it looks like we were wrong. It does have an effect as long as core can utilize memory controller 100%. Lower mem - lower hash and power consumption, higher mem - nothing happens, mc just sits and waits for work.
I went so far that I tested 720/750, again same ratio, mc load close to 100%.
I didn't have time to verify this but it looks like 390 could be the first no Nano 20MH/100W card. 310W from the wall and ethminer hashrate somewhere at 40MH area.
From your observation, the hash rate is limited by the Core frequency. The more core, the better. So the 390x should have higher hash rate, but it is at best same as 390. Quite strange.
It is. Based on my tests to get mc 100% loaded at 1500MHz you would need 1400 core which is obviously impossible.
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