I am not sure if I didn't missed something, but did anyone do a real OC? I mean OVER 275MHz?
I am currently doing 1.2TH at 300MHz @ 0.775-0.815V, did anybody tried more? how is the GH/W?
C1 at 100-275MHz has following chart, it should be similar as on other devices based on BM1382 chips - S3, U3 and S4.
100MHz @ 0.625V
(ASICs do not work below this voltage) : 192W =0.48W/GH
175MHz @ 0.650V : 356W =0.51W/GH
250MHz @ 0.720V : 650W =0.65W/GH
250MHz @ 0.760V : 662W =0.66W/GH
275MHz @ 0.760V : 809W =0.74W/GH
275MHz @ 0.800V : 900W =0.82W/GH
300MHz @ 0.815V : not yet measured
Hope anyone is interested.
Please note that best W/GH ratio can be reached by lowering input 12V voltage, such as 9V, but highest eff. power supply can be done only at high voltages (12V and up) which can also dismiss conducting losses between PSU and miner.
This measurement was done at miner, not at the wall.
Interesting. I may give your suggestion a test eventually. One thing I did notice with my unnamed cheap adjustable power supplies, since I flipped my rad fans so I could have the ports and wires inside a window, and I note it was raining when I did the flip, my power at the wall has gone from 860 watts to 880 watts. I check my voltage at the miner and it's 12.08vdc same as it had been when I set it up (setting the voltage at 12.15vdc no load), then I checked the wall voltage. The wall voltage is at 118.1. When I shut down the miner it comes back to 120.1vac. The miner is on one of two lines I ran to the living room for AC and my treadmill. I'm kicking myself for not running 12-2 Romex instead of 14-2. These two lines run to to a pair of half size circuit breakers. The room temperature has come up from mid-60's to high 70's. Outside temperature has come up 20° since the low power days of 860 watts at the wall (includes the pump). So, when it's raining and the indoor humidity is 56.5%, cooling is reduced (low mass air drawing away less heat) and efficiency drops. Also perhaps my cheap power supplies efficiencies drop in a warmer room and high humidity.
I'm running the C1 on 4 PCI-E connectors. I had ordered another 4 of the connectors late and they arrived at my post office box the other day and I'm about to run into town for those. So, later today the C1 will be running on 8 PCI-E lines. Presently the leads to the 4 connectors are warm, dropping voltage. So, before I install the new leads I'll carefully check the power at the wall. If it's as you indicate, the reduced voltage drop between my supplies and the miner should cause an increase in power consumption - unless the efficiency of my power supplies suffer as the miner improves - the supplies are running at ½ full load each.
So, home with the PCI-E-6 connectors. The power supplies were seeing 118VAC, wattage 880 at the wall and output of the supplies was 12.09vdc. The wires from the supply to the C1 were warm. Only 4 of the 8 connectors on the C1 were occupied. Completed a pair, shut down the C1, added the 2 new to one side and fired up. At fire up wattage was 870 and after 20 minutes it was up to 889 watts at the wall. Finishing the second pair of wires, shut down, added the final pair of leads, now all 8 connectors occupied, and at fire up the wattage was 838 watts at the wall, 118VAC. After 20 minutes, wall wattage measurement is 856 watts, wall voltage 117.9VAC, power supplies voltages 12.10vdc.
What this is telling me is that the supplies' voltages rose 10 millivolts due to decreased load as a result of reduced voltage drop in the lines from the supplies to the PCI-E connectors. The higher voltage at the PCI-E connectors allowed more efficient mining. I was somewhat remiss in failing to record the voltage drop between the supplies and the PCI-E connectors before doubling the wiring. The rise in the supplies' voltages would have been greater if the AC voltage at the wall had remained at 118VAC instead of dropping to 117.9VAC as the supplies' outputs to some degree track changes in wall AC. This was shown when wall AC voltage rose exceptionally high when the neighborhood shut down air conditioning on cool evenings.
After an hour the wattage at the wall is varying between 854-857 watts.
