S3+ (BM1382) Overclocking with voltage setting

[pekatete]

I am going to go buy some thermal paste tonight or tomorrow and then I will max out the OC on my units.  Has anyone successfully actually gone to 400 MHz sustainably?

I'd have liked to try that but the datasheet does not provide a voltage setting for that frequency, it literally only provides the four in the first table of the opening post! Also, the largest PSU I have available to run the S3 rigs is a measly 670W.

[klondike_bar]

if you are running at a freq of 250, there's no harm at all in notching it up to 262.5 since it is the same voltage setting (and thus same wattage draw only run faster!)

higher frequency, same voltage = higher wattage draw.

w/gh will not change significantly, but the power raw at the wall will increase (almost) linearly with the frequency at any specific voltage

If you insist on splitting hairs, then it'd be best to be exact on how much more (specific) wattage draw there is between freqs 250 and 262.5 at the suggested 0.75V

Cant say for sure, but it would be approximately 262.5/250 = 5% higher. difference between ~400W and ~420w

[luckypyrate]

Dude whatever as long as my units aren't maxing out my 750W corsairs at the wall I could care less.

[pekatete]

If you insist on splitting hairs, then it'd be best to be exact on how much more (specific) wattage draw there is between freqs 250 and 262.5 at the suggested 0.75V

Cant say for sure, but it would be approximately 262.5/250 = 5% higher. difference between ~400W and ~420w

From my calculations (excluding power consumption of other bits, e.g fans and dc/dc converters), I have:

For freq 250 32 chips @ 0.75v 12.24A = 293.76 Watts
So, by your linear model: 262.5 / 250 = 1.05 (factored to the amperage) =>12.852
For freq 262.5 32chips @ 0.75v 12.852A = 308.448 Watts

Making a grand difference of 14.68 Watts. Tell me if I am splitting hairs here ... I mean to say, even 20 watts is not exactly pushing the envelope!

Dude whatever as long as my units aren't maxing out my 750W corsairs at the wall I could care less.

My thoughts exactly .... though I blew up my 550W rated PSU running my rig @ 0.85v !

[pekatete]

Updated OP with 2 days screenshot running freq 262.5 @ 0.75v

[luckypyrate]

If you insist on splitting hairs, then it'd be best to be exact on how much more (specific) wattage draw there is between freqs 250 and 262.5 at the suggested 0.75V

Cant say for sure, but it would be approximately 262.5/250 = 5% higher. difference between ~400W and ~420w

From my calculations (excluding power consumption of other bits, e.g fans and dc/dc converters), I have:

For freq 250 32 chips @ 0.75v 12.24A = 293.76 Watts
So, by your linear model: 262.5 / 250 = 1.05 (factored to the amperage) =>12.852
For freq 262.5 32chips @ 0.75v 12.852A = 308.448 Watts

Making a grand difference of 14.68 Watts. Tell me if I am splitting hairs here ... I mean to say, even 20 watts is not exactly pushing the envelope!

Dude whatever as long as my units aren't maxing out my 750W corsairs at the wall I could care less.

My thoughts exactly .... though I blew up my 550W rated PSU running my rig @ 0.85v !

Hmm....I have mine set to 0850 right now...maybe I will me the adjustment per your recommendation tonight.  Is there a notable hash increase?

[pekatete]

Hmm....I have mine set to 0850 right now...maybe I will me the adjustment per your recommendation tonight.  Is there a notable hash increase?

Running at a freq of 262.5 with a voltage setting of 0850 will not be as efficient as running with a voltage setting of 0750, as you'll get more HW errors. At the very worst though (assuming you have an an adequate PSU), you'll be wasting power as the combined wattage is 544W whereas at 0750 it is ~294W. (note the wattage I mention here is theoretical and will actually be more!)

Classically, that is what we have been doing wrong all along, i.e running / overclocking the rigs with different frequencies at the same voltage setting! It should have been setting a voltage for a range of frequencies, but now we are wiser.

[luckypyrate]

Hindsight, my friend...history makes for good lessons...

[ZymurBits]

Sorry for the silly question but I just put the voltage setting in the voltage box under the drop down for the Frequency, correct? 

[pekatete]

Sorry for the silly question but I just put the voltage setting in the voltage box under the drop down for the Frequency, correct?  

No such thing as a silly question, simply a question.
Yes, type the voltage setting inside that box and click Save & Apply (cgminer will restart after that and no need to reboot), else if you click Save, the setting will be applied next time you reboot the rig.

[daddyfatsax]

Pete, one day I will find you and give you the biggest high five ever. Thanks for the guide man!!!

[pekatete]

Pete, one day I will find you and give you the biggest high five ever. Thanks for the guide man!!!

Pete ...!? You talking to me? High fives all over then, and the pleasure is all mine.
I also noticed that the default voltage setting that bitmain ship with is 0725 but there is no mention of any 5 thousandth in the datasheet, so naturally, I tried it on one of my rigs that I had running at 0750 (aka tried 0755) ...... not bad!

[daddyfatsax]

Pete, one day I will find you and give you the biggest high five ever. Thanks for the guide man!!!

Pete ...!? You talking to me? High fives all over then, and the pleasure is all mine.
I also noticed that the default voltage setting that bitmain ship with is 0725 but there is no mention of any 5 thousandth in the datasheet, so naturally, I tried it on one of my rigs that I had running at 0750 (aka tried 0755) ...... not bad!

Shit, sorry. I always read it wrong...

[ZymurBits]

Does the voltage reset to default after reboot?

[pekatete]

Does the voltage reset to default after reboot?

It does not reset to default so long as you save it once you have set it. I simply do a Save & Apply after setting and do not need to reboot as that action restarts cgminer.

[Subw]

Are S3's really have voltage change capability?
Anyone checked actual wattage from the wall?

[jjiimm_64]

Are S3's really have voltage change capability?
Anyone checked actual wattage from the wall?

Yes, i did, and did NOT see the actually wattage change.

[HerbPean]

This thread is F******** EPIC.

Now i have two units that had trouble running at stock ... running at least at 250 with lower voltage.

One of them is at 262.5 running at 524gh at the moment. I couldn't even make it run at 441 at 218.75 back then.

Thanks you so much for this !

EDIT: i got two running a gold corsair 1000 watts PSU and one a bronze corsair 750 watts pulling 1377-1378 Watts

hahah

[pekatete]

This thread is F******** EPIC.

Now i have two units that had trouble running at stock ... running at least at 250 with lower voltage.

One of them is at 262.5 running at 524gh at the moment. I couldn't even make it run at 441 at 218.75 back then.

Thanks you so much for this !

You are welcome, mind though that the pleasure, like custom dictates, is all mine!
PS. Would be nice if you explained how and why you had to update the firmware of your S3 for other users .....

[HerbPean]

This thread is F******** EPIC.

Now i have two units that had trouble running at stock ... running at least at 250 with lower voltage.

One of them is at 262.5 running at 524gh at the moment. I couldn't even make it run at 441 at 218.75 back then.

Thanks you so much for this !

You are welcome, mind though that the pleasure, like custom dictates, is all mine!
PS. Would be nice if you explained how and why you had to update the firmware of your S3 for other users .....

With pleasure !

First, i have 3 S3, Two Batch 1 which one was OC to 250 and one had trouble even running at 441 at stock clock (218.75). Then I bought a used one like a week ago or so. This one had also trouble to be stable at default clock (218.75).

After finding this thread. I was edit my CGMiner.lua file in the /usr/lib/lua/luci/model/cbi/cgminer (writing this path by memory) and tweaking the voltage to 750 (0.75v) for the 250 Freq and 725 (0.725v) for the 225 Freq. By doing that, I had horrible result. Follwing Pekatete advice, I upgraded one of my problematic miner to the Firmware antMiner_S320141024.bin and give it a try (DO NOT USE THE NOVEMBER ONE).

So I set my Batch 1 problematic unit to 250 Freq / 750 (0.75v) Boom was stable and had no HW / problem with any chip. I could have never done that before. Setting to 225 would have gave horrible result and bad chip status (the famous X on the miner status).

Seeing those unbelievable result. I upgraded all my miner to the October 24 firmware. Set my both Batch one to 262.5 Freq (0.75v) and my third S3 to 250 freq (0.75v). The last one looks like less performing at the moment but they all been running since  short time. So let's see and wait for now.

Still, at the moment.
                UPTIME            5s AVG     AVG      HW       FREQ  Nbr. fail chip
S3 B?       0d 0h 40m 30s   516.39   495.85   0%           250    0X
S3 B1       0d 0h 26m 40s   548.47   527.99   0.0005%   262.5    0X <====  OC to 250 with the previous default setting by bitmaintech
S3 B1       0d 0h 24m 46s   546.16   518.37   0.0033%   262.5    0X