Topic: Hacking the S7 - improving efficiency through minor hardware manipulation - page 8. (Read 26515 times)

Thanks, I missed that middle "Read" button there on the "Operate" page.

I've also seen it on a few boards; I cleared the holes and programmed them as usual. Most of the miners I've sent out didn't have the same voltage across each board; they were all tested individually for coldest stability at a given frequency and then tested as a whole. It'd be the same concept as running several Compacs off the same hub but each one set to a different core voltage, whatever that stick needed to work best.

re: holes soldered closed
So far I've ran into that on 3 boards in different miners. Does not follow batches, it just seems random. I first saw that on a b6 and last saw it on a b18. No idea why Bitmain did that.

What I did was just leave those boards as stock. I suppose one could use a solder-sucker to clear the holes...

No we are not programming the BB controller -- we are programming just the MCU on each board.
Yes EACH board has to be programmed but they do not have to use the same settings. eg. a miner can have 2 boards set to 650/680mv and another can remain as stock (holes plugged) or it can be at a different voltage setting that keeps it happy.

Read means the Read button in the centre of the screen that will read the contents of the Pic on the hash board. This can then be saved using File & Export.

Each of the 2 /3 Boards has to be done individually as there is a Pic on each board. If the holes are soldered closed it means that Bitmain has not properly masked them during the flow solder process. Perhaps if these were early boards they did not program the Pic after assembly?


Rich

No but a quiet 950 watt machine getting .22 watts still has some value.

My buddies office  can use 1 s-7 and 1 s-7ln this winter  with power at 2.4 cents.

Right now I run 1 s-7ln  and I may grab a modded s-7 from sidehack in early sept.

they would run from sept to may using only 2.4 cent power.

Running different voltages for the boards in the s7 is fine. What I was seeing during tests is that when voltage was to low a board would be stable for maybe 5-10 min and then dropped out. Once the voltage is where the chips on a board are happy then the s7 performs as normal. Once I got the boards dialed in the overnight HW errors for this s7 was 0.005%.

No you cannot use different speeds between the boards in a s7.

Thanks for the update.  I ordered my Pickit 3 through amazon and didn't realize it would be shipped from Hong Kong, so it's taking longer than expected.  You answered one of my questions in your post, do different boards need different voltages and can they work at different voltages in the same S7.  What kind of HW errors are you getting?  I'm wondering if different boards need different voltages, then the sweet spot for one board (like 630 mV is 550M) won't be the same as the other (like 650 mV is 600-625M), but this might cause one board to start getting errors (like the 630 mV might not do so well at 600M).  There's no way to set the speed for different boards in the same S7, is there?

Found my problem (no PIC12F1572 device listed): Microchip has at least 2 different programming solutions and the first one I found is version 8.08, the programming software you need is v3.35 found here http://www.microchip.com/mplab/mplab-x-ide

Starting to play with me s7's and as rather expected looks like each board can need different Vcore settings. On my 1st one modded, a batch 16 1-fan, I can run board-1 @ 630mv all the way up to at least 600MHz. For boards 2 & 3 I had to use 650mv. Power dropped from 1,330w down to 995-1,010w and that is with a 120-220v step-up xmfr between my UPS and the PSU.
Most excellent.

Not sure if anyone's interested, but I'm having good luck working up S7s to run 4TH under 1000W off a DPS1200 PSU so I've got some available in the sales board. I'm working on a deal with a guy who is retiring a mine, so I should probably have more of these in the future.

Interesting; I have not been following the BTC mining tweaks lately - good old Bitmain always performs beyond advertised numbers!

You could probably get 625MHz at around 660mV, which would be a decent reduction from stock power use. The two I worked up today look to be pretty good; one of them is hitting 550MHz at 630mV with almost zero errors. I couldn't quite keep boards from dropping out at 575.

The MCU is programmed only from the 3.3V line from the controller. No power needs be connected to the hashboards or anything else for programming to work right, but disconnecting the 18-pin will prevent voltage from flowing back from the hashboard into the controller which overcurrents the PICKit.

Arrg...
Got the PICkit3 programmer,, dl'd the latest software for it http://pic-microcontroller.com/download-mplab-ide/ All well there, installed to Win7just fine. Problem is with "You'll want to set the IPE "Device" drop-down to PIC12F1572".

Guess what device is not in the drop down list? Closest match the sw will let me do is PIC12F1501 and that throws a mismatched device ID# error when trying to connect.... Possibly that device was removed in a recent 'update"?

Ideas on getting maybe an older device lib for the programmer to use?

Also details: you mentioned disconnecting the 18pin cables to control board.
Done that.
Using the PICkit to power the device with 3.375v.
So, do the hash boards need their normal +12v power to them or is the MCU for each strictly powered from the programmer?

EDIT: Looking at microchips site for the PIC12F1572, http://www.microchip.com/wwwproducts/en/PIC12F1572 its data sheet starts with:
"PIC12(L)F157X microcontrollers combine the capabilities of 16-bit PWMs with Analog to suit a variety of applications"

I'll try that tomorrow as I recall seeing the LF version listed... Really wanna get my my 22 online s7's knocked down in power. Looking to run using 625MHz vs default 700 for clock as that produces 4.1THs vs 4.7THs, should be a good target for when I can get the Vcore reduced

No, it's really not possible to get the S7 reliably below 0.2J/GH which is still twice the power of the S9. Check the chart on page 4.

If this S7 improvement venture is successful, are you going to have an equipment that will perform almost as good as a S9? Because that will mean not having to buy a S9 in long run.

I've got a few I'll be doing similar work to, with intent to resell. I should probably be doing that today but it's Saturday and I want to sit on my couch instead. Probably start on it tomorrow.

At 825W you can get away with 2 cables per board (assuming they're not garbage cables), so a less-well-outfitted PSU can still do the job.

Decided to try and see if I can do this myself.  Ordered a Pickit 3 and have a S7 that's not doing anything right now.  

Goal:
To try to get the 3 blades running at the same speed one of my S7-LN with sidehack's mod. is running which is 660/630 mV I believe (I'd initially set the modded S7 at the sweetspot of 550M=806w and increase speed until HW errors start showing up, or at 670/640 mV running at 587.5M=900w).  With the 2 blades/boards on the modded S7-LN it's running at 562.5M at 0.0001% HW errors.  This brings about 2,531 GH/s consuming about 550w, so with 3 blades that would bring about 3,8 TH/s consuming about 825w (of course 575M at 3.88 TH/s and 843w with near 0.00% HW errors would be even better goal at 630 mV).  That connected to a EVGA SuperNOVA 1000w P2 ($180) should be a pretty efficient setup for a S7 without the need to purchase any more splitters or adapters as there is 10 PCIe connectors with the power supply (oddly the T2 model doesn't come with the same cable set).  (If money isn't an objection, Thermaltake has a unique 1,250w power supply for $350 that can monitor the electrical usage via a celphone app. that might be interesting to some miners out there.  You'll have to get 2 of these adapters https://www.amazon.com/Express-adapter-inches-sleeved-Angeles/dp/B005H3KH9E/ref=sr_1_1?ie=UTF8&qid=1468701899&sr=8-1&keywords=EPS+to+PCIe as well as figure out how to convert 4 of the PCIe 8-pin connectors to 6-pin connectors.)

I bet this would become a pretty popular hack to the S7's (batches with 135 ASIC) if it's easy to do and obviously these hacked models would sell for more after you're done with the S7.  Anyone know what a S7 pulls from the wall at 562.5M unmodded?  Edit:  Pulled out my Kill-A-Watt.  It's about 1,175w at the wall connected to a Corsair 1,500w Titanium.  So that means about 350w reduction, that's about 29.8% I think (default on the S7 is 690 mV or 700 mV I believe, that's how they get 1,293w=4.72 TH/s at 700M?).  Who would't rather have a S7 that uses about 30% less electricity at the same speed, even if it did only 3.8 TH/s, unless you've got free electricity?  If BitMain sold the power supply bracket separately, I bet you could sell a S7-LW (Low Wattage) version with the EVGA 1000w P2 together as a set.

I'd watch for a HW percentage below 0.01 - that's when I started noticing the effective hashrate dropping out. Make sure to keep fans low too; these boards really like to be kept above about 45C to run stable and at low powers it takes almost no fan to do that, especially with the oversized heatsinks in the LN.

Thanks for the additional info... It looks like 630 might not be the ticket either. I've got one board only showing 44 chips, and a half dozen HW errors.

I know 610 and 600 are specifically labeled "unstable" in the chart, but it's also noted in places that 620 isn't always reliable either. A lot of the group-buy miners weren't stable until 630 or 640. I did each of those on a per-board basis. I've got an S7 right now that has been dropping one board at like 670 for 550MHz so it really depends on the hardware. If a board runs unstable or drops out, the voltage is too low.

Know that the S7LN restarts cgminer. It runs for about a minute to warm up the chips (during which time you'll see hundreds of errors) and after that it should kill and restart clean. The firmware shifts to cold running about 30 seconds into the restarted process. At least that's how it should work - sometimes cgminer doesn't restart and you're left with the jillion errors.