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Topic: Is the S5 string design safe and was it really tested properly? (Read 5860 times)

legendary
Activity: 4256
Merit: 8551
'The right to privacy matters'
yeah I recall a few people tried doing the 24volt 2x series wiring 2 or 3 years ago with mixed results.

While I tinker quite a bit with electronics I am self taught and I am colorblind. (which is why I am self taught)

  Really fucking annoying to have colorblind issues when I like to do electrical projects.  I have reach the age of 58 without burning down my house or some friends homes (knock on a lot of wood)

 here is why  :
 If the wires are many and the colors are tough I call the wife  with 'honey'   purple or blue/ orange or red/ green or brown ?    So far so good.
legendary
Activity: 3374
Merit: 1859
Curmudgeonly hardware guy
When I said "isolated from neutral" what I meant to say was "isolated from ground" (chassis/earth ground). I've been doing more panel wiring than device-side wiring lately, where neutral is ALWAYS neutral and tied to ground. Thanks for the correction and clarification.

A lot of times the thing required to isolate a server PSU is insulated washers between the board and case standoffs. Depending on how ground planes are run, insulated (usually plastic) screws might be required as well. But yes, everything MrTeal just said is correct - if you do it wrong, the best case is the supply trips out; the worst case is it burns your house down and/or kills you so be careful.
legendary
Activity: 1274
Merit: 1004
With PSUs the thing to worry about is isolation. Make sure the ground on the output is isolated from mains neutral or they'll trip out and/or smoke when you try to turn them on in series. DO NOT connect load-balancing pins on server supplies in series. It shouldn't be needed anyway.

I recall something on anandtech  someone ran 2  separate  12 volt rails from 1 psu and got 24 volts.  but that was a while back and I did not really check it out.

*The following is not to be considered professional advice.

An modern ATX PSU has the mains lines (hot and neutral, or hot/hot) isolated from the output and from ground. Besides being a safety thing, it's a requirement of being able to run 240V into them in places like NA where 240V is two legs that are 120V w.r.t. ground. The chassis of the supply is of course connected to the ground pin on the incoming mains cable. That is a safety thing and should not be tampered with.

In and of itself, that would not cause an issue with stacking PSUs. However, ATX PSUs also have the 0V output connected to the chassis and therefore the earth ground. You would not be able to stack PSUs without shorting out the bottom PSU because of this. There are quite a few pages out there where people have converted two server or ATX PSUs into a large 24V supply for charging LiPo batteries or the like, but it involves opening up the case and removing or isolating the supply, so it is a risky "do it wrong and kill someone" kind of project.
legendary
Activity: 4256
Merit: 8551
'The right to privacy matters'
With PSUs the thing to worry about is isolation. Make sure the ground on the output is isolated from mains neutral or they'll trip out and/or smoke when you try to turn them on in series. DO NOT connect load-balancing pins on server supplies in series. It shouldn't be needed anyway.

I recall something on anandtech  someone ran 2  separate  12 volt rails from 1 psu and got 24 volts.  but that was a while back and I did not really check it out.
legendary
Activity: 3374
Merit: 1859
Curmudgeonly hardware guy
With PSUs the thing to worry about is isolation. Make sure the ground on the output is isolated from mains neutral or they'll trip out and/or smoke when you try to turn them on in series. DO NOT connect load-balancing pins on server supplies in series. It shouldn't be needed anyway.
legendary
Activity: 4256
Merit: 8551
'The right to privacy matters'
I think he means stack two PSUs in series for 24V, and then put three S5 in series below it for 1/3 voltage each. It'd be about the same as people have suggested using 3x PSUs and 4x S5 for 9V each. That'd only work if the current draw per S5 is the same; likely you'll need to tweak clocking on a per-machine basis, possibly recursively, to get a series chain of miners to run stable.

Also, we should have a test PCB for a big ol' regulator on Thursday, and probably some efficiency and reliability data next week (I'm working on a good conversion efficiency measurement toolchain tomorrow). Just throwing that out there. I should really pick up an S5 to play with.


Also, raskul, don't lose hope. One of the prismas in my hosting threw a 31G share over the weekend, after throwing a 3.9G share the day before, after not working very well all week. Success is pretty random.

atx psu 's

  2 or 3 can do series  to boost voltage  live and learn.  makes sense I just never tried it.  did it lots of times with batteries.   and when the batteries charge balancing the charge them is hard.
legendary
Activity: 3374
Merit: 1859
Curmudgeonly hardware guy
I'd really like to see individually fused chips and a backup parallel current path (like the FETs on Prismas) so if one chip starts to roast it takes itself out of the circuit before catching fire and the parallel path kicks on to keep the string's current flowing. As long as the parallel doesn't smoke out (as it'd be dropping the same power as one of the hashing chips) the thing should keep running at (N-1) hashrate.

The string design does open up a lot of efficiency headroom, but fluctuating series loads will always cause room for concern.
sr. member
Activity: 322
Merit: 250
I'm not a big fan of the "chain" design on the S5's.  I'm down 3 S5's in under 2 weeks because of it.  When one chip goes, the whole hashboard is toast (not physically), 30X's.  At least with the S1/S3 you could blow a chip here and there and the rest of the board would still hash fine, albeit slightly slower.  Now, you lose the whole damn thing and are down half a miner in one shot.

One of them burnt up immediately after turning on, the fan didn't spin and we didn't catch it in time, the smell alerted us to something wrong.  I'm not sure if it would have physically burnt, but it was certainly too hot to touch right after powering it off.

The open air design itself shouldn't be a fire hazard, however, unless you've got metal on metal and an open wire hits it.

Most of them do reliably overclock to 387.5, resulting in roughly 1.25TH.  Some are decently stable at 412.5 @ 1.35TH.  Some are unstable at the stock speed.

legendary
Activity: 3374
Merit: 1859
Curmudgeonly hardware guy
I think he means stack two PSUs in series for 24V, and then put three S5 in series below it for 1/3 voltage each. It'd be about the same as people have suggested using 3x PSUs and 4x S5 for 9V each. That'd only work if the current draw per S5 is the same; likely you'll need to tweak clocking on a per-machine basis, possibly recursively, to get a series chain of miners to run stable.

Also, we should have a test PCB for a big ol' regulator on Thursday, and probably some efficiency and reliability data next week (I'm working on a good conversion efficiency measurement toolchain tomorrow). Just throwing that out there. I should really pick up an S5 to play with.


Also, raskul, don't lose hope. One of the prismas in my hosting threw a 31G share over the weekend, after throwing a 3.9G share the day before, after not working very well all week. Success is pretty random.
legendary
Activity: 4256
Merit: 8551
'The right to privacy matters'
if the time comes, and S5's need to be undervolted, can one -instead of changing the PSU to 9V- run 3 Antminers on 2 PSU's so 24V/3=8V per S5?

no.   biggest reason is  testing shows the s-5's don't want to go lower then 9.5 volts I believe MR Teal  was able to go no lower.


second reason is   I have no idea how 2x 12 volt psu's  would down volt to 8 volts.     what would happen is  each machine would get 12 volts   and a share of the available watts the 2 psu's can provide.  assuming you plugged the gear in correctly.


in order to down volt the power from a psu a big version of this is needed.

http://www.amazon.com/gp/product/B00OT58TL4/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1


plug in psu pcie 's and crank the volts down to 10 volts or so.
legendary
Activity: 1600
Merit: 1014
if the time comes, and S5's need to be undervolted, can one -instead of changing the PSU to 9V- run 3 Antminers on 2 PSU's so 24V/3=8V per S5?
member
Activity: 123
Merit: 10
there is not a lot of evidence of  an  s-5 burning up .   



just mine  Undecided
i asked Yoshi if I could mine on antpool with my SP20's and he said yes.

what's the difference between solo. and p2p. on antpool?

On solo you get 25 BTC when you find a block. p2p antpool is a regular pool.

meh. i reckon it'd take me about 3 months to get up to 40bill

solo.antpool.com should be antpool solo with 35-42ph. All my sp20 mining there. (switch from ghash)
p2p antpool not going well, many of us complain not getting share in few days.
sr. member
Activity: 434
Merit: 250
there is not a lot of evidence of  an  s-5 burning up .   



just mine  Undecided
i asked Yoshi if I could mine on antpool with my SP20's and he said yes.

what's the difference between solo. and p2p. on antpool?

On solo you get 25 BTC when you find a block. p2p antpool is a regular pool.

meh. i reckon it'd take me about 3 months to get up to 40bill
legendary
Activity: 1904
Merit: 1007
there is not a lot of evidence of  an  s-5 burning up .   



just mine  Undecided
i asked Yoshi if I could mine on antpool with my SP20's and he said yes.

what's the difference between solo. and p2p. on antpool?

On solo you get 25 BTC when you find a block. p2p antpool is a regular pool.
sr. member
Activity: 434
Merit: 250
there is not a lot of evidence of  an  s-5 burning up .   



just mine  Undecided
i asked Yoshi if I could mine on antpool with my SP20's and he said yes.

what's the difference between solo. and p2p. on antpool?
legendary
Activity: 4256
Merit: 8551
'The right to privacy matters'
there is not a lot of evidence of  an  s-5 burning up .   


clock it to freq 325   with a decent psu .  you should be safe.

I think the one that burned up for raskul

is the only documented one burning out.


In contrast the asic miner prisma had at least 5 or 6 photoed burnouts posted on this site.


In general Antminer gear has been pretty good for most of us.

hero member
Activity: 518
Merit: 500
So i just got 5 S5's

tbh i never had a bitcoin ASIC miner till now, i have been only mining with GPU's ( altcoins )

SO about the S5, after reading this thread i am kinda afraid to even start it Smiley

If i do not oc the miners, are they safe ?
And all here are talking from experience i guess ( they also have S5's ? )
sr. member
Activity: 434
Merit: 250

I had a 1600 EVGA which was only running one SP20... it went up in a puff of smoke... Sp20 is more about getting the settings right... I have three SP20 and each of them are able to go to 1.7TH/s
sorry, my bad.. i meant it was the PSU which went up in smoke, when the S5 blew a hot-thingy-ma-jig. the SP20 is fine, no problems whatsoever. GUI's all returned no problem too, so we all good.
here is it now:



i think i recall responding to that one.


I have 2 x 750's on one SP20, 1 x AX1200i on another and 2 x 650's on another
all running ~1.4TH/s. settings on each:

Fan Speed 20
Start Voltage 0.69 / 0.69 / 0.69 / 0.69
Max Voltage 0.695
Max Watts 250 / 250 / 250 / 250

So is it safe to oc S5 ?
No. Only if you have a good fire alarm system and own guardian angel 24/7

S5 is in my opinion the fire hazard in this open air case.

totally agree with that, i'm afraid.
legendary
Activity: 1218
Merit: 1003

I had a 1600 EVGA which was only running one SP20... it went up in a puff of smoke... Sp20 is more about getting the settings right... I have three SP20 and each of them are able to go to 1.7TH/s
I read here something else
https://bitcointalksearch.org/topic/powering-a-sp20-920699


I have 2 x 750's on one SP20, 1 x AX1200i on another and 2 x 650's on another
all running ~1.4TH/s. settings on each:

Fan Speed 20
Start Voltage 0.69 / 0.69 / 0.69 / 0.69
Max Voltage 0.695
Max Watts 250 / 250 / 250 / 250

So is it safe to oc S5 ?

No. Only if you have a good fire alarm system and own guardian angel 24/7

S5 is in my opinion the fire hazard in this open air case.
full member
Activity: 182
Merit: 100
So is it safe to oc S5 ?
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