Someone linked this thread elsewhere so I thought I may as well add that I released a current master cgminer release 4.9.1a for the S1
https://github.com/kanoi/cgminer-binaries/tree/master/AntS1
Topic: AntMiner S1 Underclocking, a thorough discussion (Read 8377 times)
If it's there I'll find it.
Also noteworthy, the BTCGarden AM-V1 blades use almost identical VRM circuitry but two chips per instead of three, so an optimal point on a Tube should result in a slightly more efficient point (reduced current means reduced resistive losses in the regulator) on one of them with the same hardware mod. I may do a full analysis of a Garden board for comparison, if I have time.
Also noteworthy, the BTCGarden AM-V1 blades use almost identical VRM circuitry but two chips per instead of three, so an optimal point on a Tube should result in a slightly more efficient point (reduced current means reduced resistive losses in the regulator) on one of them with the same hardware mod. I may do a full analysis of a Garden board for comparison, if I have time.
I'm looking forward to your ASICMiner results sidehack, I under & over volted Rockminers RK/R3 boards and could not find any significant gh/w benefit worth chasing.
Trends
Trends
Just as a note, I'm starting an analysis on ASICMiner Tubes to see where they'll go. Our facility has hosted Tubes in the past, so I'm thinking about if the numbers look good, offering to undervolt for free any Tubes people want to send for hosting. They're getting to end-of-life definitely, but once we've completed our electrical upgrade and shift to the new rate schedule, all hardware will be $0.10/KWh flat. If I can get Tubes to put up decently in the 0.5-0.7W/GH area it might be worth looking into.
I should have results posted in a few days once I'm done running the jillion tests.
I should have results posted in a few days once I'm done running the jillion tests.
Who is running at .75v?
Ive got decent stability around 0.75-0.77V / 200-206MHz / TO=55 works and 90-100% of chips run well to produce 95-105GH/S1
going any lower to 0.7-0.74V / 193-200MHz / TO=50-60 seems to produce mixed results, usually 50-80% of the chips function and I have around 50-75GH/S1
going any higher to 0.78-0.82V / 200-215MHz / TO=50-60 seems to produce decent results, generally 70-90% of the chips function and I have around 95-115GH/S1
i think these dont necessarily run well at the same settings as the S2 for whatever reason. running around 0.75-0.78V and 200MHz is probably the sweet spot
nice thread can't believe I have not read it until today.
Sometime when I have time I might crank mine down around 0.8, but right now they're still coming out ahead.
Also, I'm hoping to do a full workup on AM Tubes next week.
Also, I'm hoping to do a full workup on AM Tubes next week.
Who is running at .75v?
I still got to get around to underclocking mine so I can turn them back on!
Looks like we're getting some BTCGarden blades in, and possibly a KnC Jupiter module, so I might have some underclock data on those things in a few weeks. Depends on when (and if) stuff arrives, and what kind of time I have between jobs and holidays.
looking forward to it :-)
Looks like we're getting some BTCGarden blades in, and possibly a KnC Jupiter module, so I might have some underclock data on those things in a few weeks. Depends on when (and if) stuff arrives, and what kind of time I have between jobs and holidays.
I have exactly one AM-V1, but we just got it in for the museum and I don't really feel like messing with it. I have nothing at all from RockMiner. If anyone's got either to sell at reasonable prices I can look 'em over.
It probably won't be quite as straightforward to run as an S1, but... actually, I bet it will be if I can cgminer it. The VRMs are the same 53355DQP as the S1, S2, Cube, AM-V1 and a bunch of other hardware use, so I already know everything required to do the work. Just gotta find the time.
I would be inteested to know if the AM-V1 can undervolt, same with rockminer gear.
MY EXPERIENCE WITH ROCKMINER VOLTAGE (relevant to rk-box and r3):
The regulator on these boards is not marked, but looks just like a TPS53355 seen on Antminer S1/S2 and Bitfury boards. However, it is arranged differently, without the same placement of R1/R2 that are used for raising/lowering voltage. (aplying pencil to R1 raises voltage, R2 decreases voltage). In the case of rockminer, no resistors were acessible that would reduce the voltage when resistance was reduced. only the oposite was seen - increase in voltage when R1 and R2 were simultaneously modded. physical replacement of the resistors would be the only solution i think
looks a lot like the TPS53355 regulator in this picture, with two resisters right by it - if so should be quite easy to pencil mod
http://www.ti.com/lit/ds/symlink/tps53355.pdf - look at the bottom image on page 7, the reference on page 20, and figure 38.
TLDR; Pin 1 has two resistors on it, R2 goes to ground and R1 goes through a small circuit. The choice of values for these gives the output voltage. This is how the Bitfury overvolts, and how the S1 can over/undervolt. looking at the rockminer PCB (would love a high-def image of the section), this is the solution to undervolt for efficiency:
some pencil lead on R2 increases the output voltage, while lead on R1 would decrease it. Presumably the efficiency could be brought closer to the 0.7w/GH achieved by the prisma this way
*note*: Im basing this on a blurry image and dont have a PCB in front of me to confirm that Pin 1 is the right corner of the chip, but the positionng of the two resistors like that seems logical. hopefully ill try myself on monday evening
update: I brought a unit home, and am unable to determine any markings on the regulator component. looks an awful lot like the TPS5355 though, and as there arent many >20A alternatives I would assume that it is.
however, my expectations were not correct. pencil modding either R1 or R2 (or any other resitor in the vicinity of the regulator) has no visible effect. It appears that R1 and R2 in my above image are both brought to ground together.
HOWEVER - I made an interesting discovery - pencil modding BOTH R1 and R2 results in the output voltage increasing, with 1.15V achieved quite easily using a 2B pencil (stock is 0.75V). Obviously this is the opposite of my intentions though.
UPDATE 2: Partial destruction of R1 and R2 (chipping the sides of the resitors with a sharp tool) so that each is roughly 3.3kOhm when measured in circuit results in a regulator output voltage of 0.6V Testing now -> preliminary results are mediocre at best - 16GH. However, its worth noting that this unit has always been a source of problems, and that two other boards in it report 25GH and 58GH, neither of which were modified in anyway. Not sure if its a USB hub issue, RPI, or maybe even something to do with the server PSU (providing 12.03V)
UPDATE 3: replaced a controller on a different board that was causing reboots and often not functional -> 110GH,90GH, 105GH, 70GH. Obviously there is quite a spread here but it seems like the modified board is functional. Because of difficulties operating (or lack of) at 0.6V, pencil mod was added to increase the voltage to 0.7V on the modified (70GH) board. Reject rate is 6.5% at 300MHz
UPDATE 4: 12hr stats: 112,112,111,66 GHash across the 4 boards, with the 65GH board being the one i modified. Total reject % is 4.3.
TLDR; Pencil mod is not easily implemented on the RK-Box. reduction of chip voltage to 0.7V significantly impacts hashrate, and voltage below 0.65V is often non-functional. No efficiency numbers available yet
That's how I did the first, with a pot on a big ol' knob for super fine adjustments (I could tune it to 1mV easily). I've got resistors premade now to parallel on the existing 8200s that make 10mV increments, and I've been setting one bank, running for a few minutes, then moving up or down as necessary until the error rate hit threshold. I've a parts order coming Monday with the actual SMD resistors to do the swaps proper, instead of having through-hole resistors hanging off the boards.
I definitely need to read that external-controller thread for these guys and see what work y'all have done.
I definitely need to read that external-controller thread for these guys and see what work y'all have done.
Also, if you have the time to tune instead of setting all banks to the same stock value, I've been finding some banks that worked at voltages lower than my test data. I have one S1 that's pulling 140GH at 152WDC including fan and controller. I think every bank is at 830mV or better with ~1% HW though my test board did that at 850mV. Course one I did today had a few banks that required 860mV to stay clean.
I'm seriously impressed with their chips. 0.8W/GH is pretty good for year-old hardware that shipped at 2W/GH and was already ahead of the curve. I've got 12xS1 on a single DPS2K with power to spare. Figure in four or six months I'll take 'em to the lowerbound and keep 'em going for a while. They're helping fund the museum right now.
Here in another month or so (if I get time; we're starting to get some real work coming in) I plan on doing the same in-depth analysis on AM Tubes.
i have brought a bunch of potentometers that im adding to each blade (4 per section) and i plan on using that to fine tune each section, and adding them all together on the same controller (1 rasbpi) currently i have 5 done (those are pencil modded) so waiting for the last cp2102s to arrive to get the rest done, and waiting for those potentometers to arrive from china...
its amazing how much these chips can be pushed, but then, it just shows the craftmanship of these chips.
That is also an excellent point. I've got twelve running at the shop right now (underclocking is a work in progress) and it's a bit of a pain to reconfigure them when necessary.
I wanted to do it more from a "manageability" perspective. Having so many individual controllers is a bit of a pain. Right now I use a proxy for all my S1's. Would be nice to
have one Cgminer instance for all of them.
have one Cgminer instance for all of them.
The stock S1 controller, by my measures, only draws about 1W. Not too worried about that power overhead. But it would be nice to rig up something with more space-efficient cooling. Might as well use a single combined controller if you can get them stripped down and lumped into a more compact unit.
Oh, if anyone feels sufficiently benefitted by this work to toss donations, use the BTCMuseum address in my sig. We're buying up old hardware to put together a display of mining history, right now it's all funded by Novak and I's donations and mining on the stuff we're collecting.
Oh, if anyone feels sufficiently benefitted by this work to toss donations, use the BTCMuseum address in my sig. We're buying up old hardware to put together a display of mining history, right now it's all funded by Novak and I's donations and mining on the stuff we're collecting.
I did the block erupter to uart adapter thing too. Love breathing new life (or repurposing) old hardware. I am thinking about making a high density miner based on the
S1 hardware. Would like to get about 20 S1 blades running on one controller.
S1 hardware. Would like to get about 20 S1 blades running on one controller.
Right, I've got a handful of machines in hosting using Crazyguy's image for Pi and Cubie running Prismas. It's handy, but the interface (at least what little I've seen) doesn't provide near as much information as I would require to do the job right. I'd rather use a standalone (AM-specific) cgminer instance I can get full data from on the fly. I've never really been a fan of RPi myself, rather use a real computer if I can.
Regarding that adapter, Novak and I work together (GekkoScience is the business we started together) so I already know about 'em. He used one of my old Block Erupters to prototype on. I'll probably use one of the adapters he's gonna be batching (https://bitcointalksearch.org/topic/unofficial-usb-adapters-for-asicminer-tubeprisma-882348, I think about half of them are sold already) to do the testing, if he has any left by then. Pretty handy stuff that guy does.
Regarding that adapter, Novak and I work together (GekkoScience is the business we started together) so I already know about 'em. He used one of my old Block Erupters to prototype on. I'll probably use one of the adapters he's gonna be batching (https://bitcointalksearch.org/topic/unofficial-usb-adapters-for-asicminer-tubeprisma-882348, I think about half of them are sold already) to do the testing, if he has any left by then. Pretty handy stuff that guy does.
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