Bitmain S4 Hacking, Mods, Underclocking, Undervolting

[lovenlifelarge]

Show us what u got??

Trying to find a good list of all if any mods for the S4 that are out there??

No one seems to have done this??

Ill put one in for those who didn't know...

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Undervolting or Overvolting is only available with the October 16th firmware

The best underclock or undervolt i have seen out there is

Freq 175mhz

Volt 0700

For 1085w from the wall & hashing at 1754gh...

Another is

Freq 162.5

Volt 0670

For 1500gh at 1000watts

Another is

Freq 175

Volt 0680

Unsure of watts hashing at unknown gh

Another is

Freq 187.5

Volt 0720

Gives 1800gh at unknown watts

Another is

Freq 187

Volt 0700

Gives unknown gh at unknown watts

I will try these myself with a kill o watt shortly

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Overclock

Freq 218.45

Volt 0745

For 2200gh @ unknown watts at the wall

Another

Freq 212.5

Volt 0740 or 0745 ur choice for stability

Gets 2150gh @ unknown watts at the wall.

WARNING WARNING WARNING

I would not suggest any overclocking using a stock bitmain PSU

IBM DPS-2000bb @ 2000watts will give u a clean punch of power to suit overclocking

Anyone else care to share??

[1715146907]

1715146907

[1715146907]

1715146907

[1715146907]

1715146907

[lovenlifelarge]

Best undervolt using oct 2014 firmware is :

Freq : 100

Volt : 0670

For 1008gh @ 640w saving approx 100w

Can anyone do better than this??

U can use Volt 0670 across any Freq setting for a marginal power saving,i found any volt setting lower than this either made the miner run at a worse w per gh than it already did or the miner just wouldn't start.

Anyone else replicate these results or better them??

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UPDATE

If u can get the J7 board to set the voltages correct on startup (This requires a kill o watt or similar)

To do this u'll need to start & restart the machine till the kill o watt tells u the right voltage / watts...

The amount of restarts is random so just keep trying it till it sets right.

Old settings as above with J7 on the loose will give 640w

With the J7 running correctly it will be 600w, That's another 40w saving....

[dimke_yu]

Very nice results, thanks!