Antminer S2 Support and Overclocking Thread

[Rabinovitch]

Well, who knows how to overclock the S2 after upgrade to newest FW by Bitmain?.. I neither can see asic-freq.config file, nor cgminer.lua... :confused:
Posted from Bitcointa.lk - #mOFq4XRsYZQJWE5y

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[MissouriMiner]

I can't even see the "lua" folder under /usr/lib/........

Oh, dang.  I'm sorry.  That was for the S3.   Try editing "/www/pages/cgi-bin/minerAdvanced.cgi".  Near the bottom of the file.

[Rabinovitch]

I added one string there, <option value=.......</option>, but when I rebooted S2 in order to make that selection available in miner's GUI, it became unavailable. After power reset everything became normal, miner is available and hashing again, but there are no my changes in that file... They were there after :wq command...

[MissouriMiner]

I added one string there, <option value=.......</option>, but when I rebooted S2 in order to make that selection available in miner's GUI, it became unavailable. After power reset everything became normal, miner is available and hashing again, but there are no my changes in that file... They were there after :wq command...

The changes will not stay after a reboot. Same behavior as the S4 and C1.

[Zorg33]

I successfully overclocked my S2 with the newest firmware by adding the options on the Web UI with firebug.
You need to add an <option> tag with the specified 'x:y:z' values from the first post, then select it and hit save&apply.

BTW, what's the default voltage? 0.75V ? I tried 216MHz with voltage 0725 and the HW went high above 1.5% with 1090GH.

[klondike_bar]

I successfully overclocked my S2 with the newest firmware by adding the options on the Web UI with firebug.
You need to add an <option> tag with the specified 'x:y:z' values from the first post, then select it and hit save&apply.

BTW, what's the default voltage? 0.75V ? I tried 216MHz with voltage 0725 and the HW went high above 1.5% with 1090GH.

I doubt theres actually a working voltage control - 216Mhz @stock voltage would give about the hash and error rates you have. When it was a new unit, i was pushing mine close to 1120GH at 225MHz

[FuryFever]

I notice there haven't been a lot of replies to this thread lately, so I'm not sure if anyone is still messing about with these Antminer S2's or not.  But, I'm having a bit of a problem with successfully overclocking my Antminer S2 that I bought a few months ago and I was hoping some pointers from this forum might get me on the right track.

I was actually overclocking my Antminer S2 with some success on the STOCK power supply (1,000 Watts Enermax).  I took the clock frequency values posted on the first page and played around with them and found I had the best luck with 216M (215.625 MHz per chip).  With this setting, I had increased my average hash rate on the miner from around 1,008 GH/s or so stock to around 1,092 GH/s overclocked.  My hardware error rate only increased to 0.96% or so (under 1%, so not bad...) and I was even getting mining pool side hash rates reported from this machine in the 1.09-1.12 TH/s range!

But, I wanted to see if I could get more out of it than that.  I had read on this thread that if you wanted to overclock the Antminer S2 more, you would need to get a bigger power supply so you could supply all the ASIC chips with more power to run them at a higher MHz clock speed.  I also read that the ASIC chips used in the Antminer S2 are the same ones that were used in the Antminer S3, but that there were fewer chips per board on the S3 and they were running at 400 MHz instead of 200 MHz like they are on the S2.  So, in my mind, I figured that if I was able to supply more voltage and wattage to the boards in my S2, theoretically I should be able to overclock the chips to 250, 300, 350, or maybe even 400 MHz and try to approach 2TH/s with my miner!

However, unfortunately that has NOT been the case!  I purchased a LEPA G1600, which is a 1,600 Watt continuous (1,700 Watt peak power) fully modular power supply to swap into my Antminer S2.  I completed the swap Tuesday night (March 31) and have been playing around with the chip frequencies and voltages since then and I just CANNOT get it to run any better than it already was on the stock power supply at 215.625 MHz chip frequency!!  What gives here?

I tried being overly ambitious at first and jumped the chip frequency right up to 250 MHz, but it would not even hash at that speed at all!  I was only getting 32-45 GH/s reporting out of the machine and I had hardware errors in the 154-175% range!  This was crazy!  How could such a relatively small increase basically break my miner and it wasn't working at all?!  I should have the power to back up this increase in chip frequency, right?  Then I tried backing it off to only 225 MHz, but that didn't seem to work much better either.  I was still getting hash rates below 100 GH/s and hardware errors in the 75-120% range.  This is ridiculous!  Then I tried backing it off to only the 219M (218.75 MHz) chip frequency and even at THAT setting I was getting a worse hash rate and more hardware errors than when I was running it at 215.625 MHz!

So, I switched my settings back to the 215.625 MHz chip frequency for now and I am still running at 1,092 GH/s average for the time being.  But it just bothers me that I was able to get that on the stock power supply and now that I have severely beefed up the power supply in it, I am unable to get any more output from my miner through overclocking it.  What gives?  Am I more limited now by cooling than I am by power?  The weird part is, even when I tried running it at 250 MHz, my reported board temperatures weren't any higher than they were at 215.625 MHz!  They were still reporting between 49 and 58 degrees Celsius, which is what they are reporting when the chips are running at 215.625 MHz as well.  So, it didn't seem like they were overheating and throttling back to me at least.  Is there some built-in limit that they programmed in so the miner won't run at all at higher frequencies?  Maybe there is a limit to how much power can be transmitted to the boards through the PCI interface and that is where it is choking now?  I notice that the Antminer S3 and S5 boards have power connectors that plug right into the ASIC boards themselves.  However, on the Antminer S2, the power plugs into the big controller board that the 10 ASIC boards plug into through PCI slots.  Could that be part of the problem?

I would really like to have my purchase of this massive power supply for my Antminer to not be for naught.  Does anyone know if it is possible to get more out of these Antminer S2's or am I pretty much at the limit of what it can do right now for some reason?  Do I need to modify the voltage field in the Advanced Miner Configuration settings in order to successfully overclock it further?  I have tried changing that setting from the stock 0725 volts to 0750, 0800, 0850, 0900, and even 0950 but it didn't seem to make any difference.  If this value is somehow actually used to do something, I'm kind of wary of setting it to a value over 1000, but something tells me that this value is not used since I don't see any difference in the way it mines regardless of what value I put in there.

Any help towards maxing out my Antminer S2 would be greatly appreciated!  Thanks in advance and I look forward to any advice you guys can give me!

[d2dtk]

The voltage is set in the machine this limiting it from its full potential. You'd have to rebuild the boards or find a way to get different voltage regulators attached to the boards.

[FuryFever]

The voltage is set in the machine this limiting it from its full potential. You'd have to rebuild the boards or find a way to get different voltage regulators attached to the boards.

Really?  So that voltage field in the Advanced Miner Configuration is bogus then and it does nothing?  Is it actually possible at all to modify the voltage from within the software at all (possibly as easy as just modifying some code or as complex as having to rebuild the firmware or something...) OR is the voltage regulated physically on the boards like you said?  So, I would have to buy different voltage regulators to solder into the boards then to try to overclock it further?  Has anyone ever tried this before?

Does anyone know if there are any voltage settings that could be passed to cgminer that might control this then?  Maybe that is all it would take?  One could hope at least, right?

[FuryFever]

So, no one has tried to change the voltage regulator(s) in one of these before or knows how to do it?  It has been a while now and I haven't seen any more replies to my posts.  Just thought I'd try to bump this back up in case anyone else hasn't seen it who might be able to help out.  Thanks!

[adaseb]

So, no one has tried to change the voltage regulator(s) in one of these before or knows how to do it?  It has been a while now and I haven't seen any more replies to my posts.  Just thought I'd try to bump this back up in case anyone else hasn't seen it who might be able to help out.  Thanks!

Changing the VRM is not that easy. Even if you could you wouldn't make it any more efficient. It would just overheat and run loud like the S1.

Its old technology.


Also these chips are the same chips as the S1 not the S3.

[FuryFever]

I was actually overclocking my Antminer S2 with some success on the STOCK power supply (1,000 Watts Enermax).  I took the clock frequency values posted on the first page and played around with them and found I had the best luck with 216M (215.625 MHz per chip).  With this setting, I had increased my average hash rate on the miner from around 1,008 GH/s or so stock to around 1,092 GH/s overclocked.  My hardware error rate only increased to 0.96% or so (under 1%, so not bad...) and I was even getting mining pool side hash rates reported from this machine in the 1.09-1.12 TH/s range!

But, I wanted to see if I could get more out of it than that.  I had read on this thread that if you wanted to overclock the Antminer S2 more, you would need to get a bigger power supply so you could supply all the ASIC chips with more power to run them at a higher MHz clock speed.  So, ... I purchased a LEPA G1600, which is a 1,600 Watt continuous (1,700 Watt peak power) fully modular power supply to swap into my Antminer S2.  I completed the swap Tuesday night (March 31) and have been playing around with the chip frequencies and voltages since then and I just CANNOT get it to run any better than it already was on the stock power supply at 215.625 MHz chip frequency!!  What gives here?

Any help towards maxing out my Antminer S2 would be greatly appreciated!  Thanks in advance and I look forward to any advice you guys can give me!

Well, it looks like possibly overclocking my AntMiner S2 plus the sudden heat wave that we got this week killed it.  I have no idea what happened to it, but all of a sudden I noticed on Friday that it just stopped hashing.  Now, it had been mining overclocked at 215.625 MHz and averaging 1,092 GH/s without needing a reboot for over 35 days straight.  It had been running rock solid with temps only in the 48-56 degree Celsius range.  However, this week the outside temperatures really skyrocketed all of a sudden (along with the humidity).  We had 75-80 degree Fahrenheit days all week, and then this past Friday [May 8], it hit almost 90 degrees out with like 78% humidity!  I hadn't had a chance to dig out the air conditioning units and install them yet, so my house was pretty unbearably hot.  It was around 92-93 degrees Fahrenheit upstairs and in the basement where my miners are it was around 94-95 degrees, despite the natural cooling that a basement can provide in the summer.

Because of the heat and humidity on Friday, I had a bunch of my miners go down, including my AntMiner S2.  (I also had problems with one of my CoinTerra miners and one of my AntMiner S5's also overheated and shut down.  I had one board in my S5 go over 80 degrees Celsius, so it shut down.)  However, my AntMiner S2 acted very weird.  The web interface went down so I couldn't remote into it anymore, but the miner was still on (or at least the power supply was still running).  The red light on the front of the miner was on and the display on the front of the miner was blank.  So, I unplugged the miner and left it off for about 10 minutes to cool down (as I assumed it overheated, even though I never saw the temperatures go over about 60 degrees on it).

However, when I plugged it back in, it is only mining at about HALF capacity for some reason!  The temperatures are also MUCH lower than they were - only around 42-48 degrees Celsius.  The weird thing though is that I have all 10 boards up and all 64 ASICs per board are showing as good (Displaying "o" in the ASIC Status and not "x").  So, there seems to be nothing that would be preventing the miner from running at 1 TH/s, yet I am only getting 511.6 GH/s out of it!  I have no clue what is holding it back, unless I fried some of the chips in it.  However, if that was the case, then shouldn't it be showing a bunch of dead chips in the ASIC Statuses?

Does anyone have any ideas on what could have happened, what to look for, and/or how to get this miner back working at full capacity again?  Should I just pull out and reseat the boards and try to clean it up a bit?  How can I tell what is preventing this miner from hashing at 1 TH/s?  Also, when I had to restart the miner, it reset back to 200 MHz per chip from being overclocked at 215.625 MHz, but it should still be running a lot faster than 511.6 GH/s.  It has been running for almost 2 days now since it shut down on Friday and the hashrate has still not increased on it at all and the temperatures are still only in the mid 40 degrees range.  Any help getting this miner back running again at full hashing capacity would be greatly appreciated.  Thanks!