Bitmain Antminer S7 Overclock w/ Data

[gta3uzi]

Hello. This is to catalog my overclock for future interested parties.

Unit: Bitmain Antminer S7
Board Versions: ? (To Come)

Date format is xYYMMDD.HHMM
Location is Alabama, USA.

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Date x180124.0400

Type:                   Bitmain Antminer S7
Cooling:               Ambient air
Run Time:            1:15
Outside Temp C:   0
Chip Temp C:       48,47,48
Freq:                   775
Dev Hash 5s:        5.058
Pool Hash Scr:     5.223
Pool Hash 1hr:     5.316
DIFF1:                5232395
DIFFA:                5572052
DIFFR:                41085
HW:                    2856
Error %:             0.0546
Volts:                 117.5
Amps:                14.04
Watts:                1650
Fan %:               30
Fan 1:                3000
Fan 2:                2640

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Date x180123.0245

Outside Temp:   5C
Chip Temp (C):   42,46,46
Chip Qty (#):   45,44,45
Freq:      768
Hash (TH):   5.00
Error:      0.03%
Volts:      115.5
Amps:      14.75
Watts:      1703
Fan %:      100%
Fan 1:      4440
Fan 2:      4200

[fanatic26]

Please setup a 24/7 camera that is recording so we can see the moment where the machine blows up and starts shooting fireballs out the back.

Overclocking bitmain gear is extremely stupid and I hope this doesnt give anyone else ideas.

[gta3uzi]

Why would it do any of that? I'm not playing with the board voltage. Somebody else did that before I bought this used equipment by soldering in some additional silicon. XD

The boards I have now are running within 2C of each other, though, so I suspect the voltage is within spec across them. I only lose 1 chip of 45 on board #2 above 725mhz, and I've run this box all the way up to 775mhz / 5.2TH/s on a particularly cold night with high mains voltage. I'm limited to 15A on this circuit / plug.

I'll soon have a 240v solution and 2x miners running. I'm also working on an ultra-efficient cooling system that should allow me to attain profitability at $0.10/kWh even with these S7's.

As an side, the cooling system should be less electrically efficient than underclocking and running outside air, more efficient than a traditional computer room air conditioner (CRAC), and it will be far more portable and space-efficient than both. It should also severely reduce interior room noise at full operating power.

I'm running 700mhz (stock freq) at ~48C right now. 12.5A.