How i can undrervolt Ant minter s1 ????????????

[noise23]

Wait, I thought the BM1380 was for the S2? Do the S1 and the S2 use the same chip? Why did I think they were using different chips? I've been sick this week, and a little out of it, so my apologies for any confusion.

Yep the S1 and the S2 use the same chip.

Lets say we went with the 0.75V @ 205MHz, and OC'd it to 245MHz. Each S1 would be making 125GH/s, and pulling 82W at the chip). That means @20% inefficiencies, and adding the fixed costs = ~130W. 8 ants would be making 1TH/s while only using 1040W (from the PSU, which means 1140W from the wall).

Sounds great 
We need to find out somehow where that resistor is and what resistance it should be changed to to get 0.75V!

[Littleshop]

Wait, I thought the BM1380 was for the S2? Do the S1 and the S2 use the same chip? Why did I think they were using different chips? I've been sick this week, and a little out of it, so my apologies for any confusion.

Yep the S1 and the S2 use the same chip.

Lets say we went with the 0.75V @ 205MHz, and OC'd it to 245MHz. Each S1 would be making 125GH/s, and pulling 82W at the chip). That means @20% inefficiencies, and adding the fixed costs = ~130W. 8 ants would be making 1TH/s while only using 1040W (from the PSU, which means 1140W from the wall).

Sounds great 
We need to find out somehow where that resistor is and what resistance it should be changed to to get 0.75V!

Due to the design of the unit I would imagine you would need to change eight SMT resistors.  A bit of a pain but interesting.

[philipma1957]

Wait, I thought the BM1380 was for the S2? Do the S1 and the S2 use the same chip? Why did I think they were using different chips? I've been sick this week, and a little out of it, so my apologies for any confusion.

Yep the S1 and the S2 use the same chip.

Lets say we went with the 0.75V @ 205MHz, and OC'd it to 245MHz. Each S1 would be making 125GH/s, and pulling 82W at the chip). That means @20% inefficiencies, and adding the fixed costs = ~130W. 8 ants would be making 1TH/s while only using 1040W (from the PSU, which means 1140W from the wall).

Sounds great 
We need to find out somehow where that resistor is and what resistance it should be changed to to get 0.75V!

Due to the design of the unit I would imagine you would need to change eight SMT resistors.  A bit of a pain but interesting.

yeah my eyes are too old but it is doable.

 maybe 100gh at 100 watts could be done.

[tzortz]

bump!

[MrTeal]

I don't see why you couldn't try a pencil mod on an S1. They just use a voltage divider to provide feedback of the output, so you'd pencil mod one to increase the voltage and pencil mod the other to lower it.

On the Antminer S1 that's R3 (8.2k) and R12 (9.76k) for the leftmost VRM, under the inductor. To make the voltage go up pencil mod (lower the resistance) of R12, and to lower the voltage pencil mod R3 instead.

[crazyates]

I don't see why you couldn't try a pencil mod on an S1. They just use a voltage divider to provide feedback of the output, so you'd pencil mod one to increase the voltage and pencil mod the other to lower it.

On the Antminer S1 that's R3 (8.2k) and R12 (9.76k) for the leftmost VRM, under the inductor. To make the voltage go up pencil mod (lower the resistance) of R12, and to lower the voltage pencil mod R3 instead.

Pencil mods are great for testing, or for minor bumps. According to my math, I would have to swap the 8.2k R3 with a 5.6k resistor, and that should bring the V down to 0.75? Anyone else want to double-check my back-of-the-napkin math?

This weekend I'd like to grab one of our S1s, underclock down to 200, replace all 8 resistors, and then see what the power difference is. After that, I'd like to see how far I can OC on 0.75v before the hardware errors go >1%.

[klondike_bar]

I don't see why you couldn't try a pencil mod on an S1. They just use a voltage divider to provide feedback of the output, so you'd pencil mod one to increase the voltage and pencil mod the other to lower it.

On the Antminer S1 that's R3 (8.2k) and R12 (9.76k) for the leftmost VRM, under the inductor. To make the voltage go up pencil mod (lower the resistance) of R12, and to lower the voltage pencil mod R3 instead.

Pencil mods are great for testing, or for minor bumps. According to my math, I would have to swap the 8.2k R3 with a 5.6k resistor, and that should bring the V down to 0.75? Anyone else want to double-check my back-of-the-napkin math?

This weekend I'd like to grab one of our S1s, underclock down to 200, replace all 8 resistors, and then see what the power difference is. After that, I'd like to see how far I can OC on 0.75v before the hardware errors go >1%.

pencil mods work well long-term, but be aware that they 'bake-in' and with age and heat the resistance lowers slightly from when first applied.  In the case of pencil-modding bitfury cards I often had a card run fine for 6-24 hours after a pencil mod before getting to a point that it couldnt stay stable for more than an hour at a time. Keep that in mind and leave a bit of headroom when testing a pencil mod.

Now that the right resistance/voltage is functioning on the bitfury, I am getting about 36-39GH per card

[crazyates]

I don't see why you couldn't try a pencil mod on an S1. They just use a voltage divider to provide feedback of the output, so you'd pencil mod one to increase the voltage and pencil mod the other to lower it.

On the Antminer S1 that's R3 (8.2k) and R12 (9.76k) for the leftmost VRM, under the inductor. To make the voltage go up pencil mod (lower the resistance) of R12, and to lower the voltage pencil mod R3 instead.

I tested our Ant, and R12 and R3 were both 4.45k?! This seems to be different than what you measured, and means to drop the voltage down to 0.78v, I gotta replace the 4.45k with a 3.07k resistor.

[MrTeal]

I don't see why you couldn't try a pencil mod on an S1. They just use a voltage divider to provide feedback of the output, so you'd pencil mod one to increase the voltage and pencil mod the other to lower it.

On the Antminer S1 that's R3 (8.2k) and R12 (9.76k) for the leftmost VRM, under the inductor. To make the voltage go up pencil mod (lower the resistance) of R12, and to lower the voltage pencil mod R3 instead.

I tested our Ant, and R12 and R3 were both 4.45k?! This seems to be different than what you measured, and means to drop the voltage down to 0.78v, I gotta replace the 4.45k with a 3.07k resistor.

Hmmm. I was just going off the schematic, but it's possible they updated it. The same principle applies though.

[lucazane]

how do you get the voltage of the asic with multimeter (on the board) ?

[tzortz]

Anyone managed to change resistors. We need results.

[jacob019]

I am also anxious to see some results.  This could be a game changer for profitability calculations by extending the life of our miners.  Once the revenue dips below energy cost, we can swap our resistors to improve the efficiency (at a reduced hash rate) and get many more months out of them.

[tzortz]

I am also anxious to see some results.  This could be a game changer for profitability calculations by extending the life of our miners.  Once the revenue dips below energy cost, we can swap our resistors to improve the efficiency (at a reduced hash rate) and get many more months out of them.

Right.

[lucazane]

I have succefully undervolt 3 antminer s1

the result are fucking awsome :

chip are at ~ 0.85 volt, freq is 08A1 (275 MHz)

~ 140 GH/s per antminer s1

500 watts at the wall for the 3 underclocked ant ! (166 per ant for 140 ghs)

The PSU is a corsair AX1200i

for comparison at stock volatage it's was drawing 1050 WATTS for 3x180 GHS !

I will make a topic to explain how later (I need time to see if it's working well)

It's running for 1 hour now without problem

the first ant  has 0.95 % of HW
the second ant has 0.3 % of HW
and the last has 0.5% of HW

[tzortz]

I have succefully undervolt 3 antminer s1

the result are fucking awsome :

chip are at ~ 0.85 volt, freq is 08A1 (275 MHz)

~ 140 GH/s per antminer s1

500 watts at the wall for the 3 underclocked ant ! (166 per ant for 140 ghs)

The PSU is a corsair AX1200i

for comparison at stock volatage it's was drawing 1050 WATTS for 3x180 GHS !

I will make a topic to explain how later (I need time to see if it's working well)

It's running for 1 hour now without problem

the first ant  has 0.95 % of HW
the second ant has 0.3 % of HW
and the last has 0.5% of HW

Awesome!

What resistors did you use?

Also, compared to standard and overclocked how is the hw percentage rate changed? Better or worse? Or same?




.

[lucazane]

The HW has increase (before I had 0.1 ~ 0.2%).

I used pencil mod on R3 (4.47kOhms => ~2.9kOhms)

[tzortz]

The HW has increase (before I had 0.1 ~ 0.2%).

I used pencil mod on R3 (4.47kOhms => ~2.9kOhms)

Since its a pencil mod, just make sure the voltage remains the same, as pencil makes different resistance under heat.

Maybe with lower resistance give lower hw?




.

[lucazane]

I made a quick guide https://bitcointalk.org/index.php?topic=526060.0

[Soros Shorts]

The HW has increase (before I had 0.1 ~ 0.2%).

I used pencil mod on R3 (4.47kOhms => ~2.9kOhms)

Since its a pencil mod, just make sure the voltage remains the same, as pencil makes different resistance under heat.

Maybe with lower resistance give lower hw?




.

In this case, under heat you will get a lower reference voltage at the voltage divider. So your HW errors would likely go up if you maintained the same frequency.

This has the opposite effect of pencil modding to increase voltage, where you'd be putting lead on the other resistor.

[GenTarkin]

I have succefully undervolt 3 antminer s1

the result are fucking awsome :

chip are at ~ 0.85 volt, freq is 08A1 (275 MHz)

~ 140 GH/s per antminer s1

500 watts at the wall for the 3 underclocked ant ! (166 per ant for 140 ghs)

The PSU is a corsair AX1200i

for comparison at stock volatage it's was drawing 1050 WATTS for 3x180 GHS !

I will make a topic to explain how later (I need time to see if it's working well)

It's running for 1 hour now without problem

the first ant  has 0.95 % of HW
the second ant has 0.3 % of HW
and the last has 0.5% of HW

Very awesome dude!
I wonder what 1v @ 325mhz will yield, it should be doable, I got a U1 @ that setup and its 0% HW