[Review] Spondoolies SP20 review - A Green miner with a Loud fan

[Biodom]

The efficiency curve:
>snipped image<

The lowest setting 0.58V is very unstable, usually half of the loops are disabled. At 0.59V I can achieve 809 GH with barely 376W at wall (0.465W/GH), and at 0.61V, I get 1TH with 500W, also feels great. The efficiency drops almost linearly across the voltage range, I did not test above 0.68V, which consumes around 950W

the curve was with what fan settings? 80-90 or lower?
fan settings would affect efficiency.
Obviously, you want fan settings to be as low as possible while maintaining working temp (<115C)

[huffdaddy5]

Just a reminder to everyone out there. Underclocking is not for everyone. If you are paying less than $0.18/Kw, then it will actually be profitable to run at stock speeds. Above the $0.18/Kw threshold you will actually start profiting (BTC-Electric) by running at underclocked speeds.

I pay $0.098/Kw, so I'm looking for the highest GH/s I can ran at while still keeping the fan speed at 40. I've been playing with all different voltages and this is what I've come up with. Note: I have this SP20 running along side an Antminer S4 and I have a 24" fan blowing air into the intake of both miners.

At the current rate of BTC income per month $0.014/TH/day I should make 0.61BTC/30days. At $330/BTC, I should bring in $201, spend $64 on electric and profit $136 every 30 days. Note that as Bitcoin difficulty increases the amount of BTC earned per month will decrease and there is always the price of BTC to factor in which changes on a daily basis.

At the nano farm price (free shipping) $1900=3x$633 and $140 for a 1050W 80 Plus Gold PSU, I'd have $773 invested per SP20. @ $136 profit, the SP20 nano farm would pay for its self in just under 6 months.

1050W 80 PLUS Gold pulling 957W at the wall
Mining Rate: 1430.13Ghs
Temp Front / Back T,B   21 °C / 67,58 °C
Fan Speed    40
Start Voltage 0.71 / 0.69 / 0.71 / 0.71
Max Voltage  0.71
Max Watts    220 / 220 / 220 / 220


Asic Stats
Uptime:2044 | FPGA ver:100
-----BOARD-0-----
PSU[UNKNOWN]: 0->217w[217 217 216] (->217w[217 217 216]) (lim=220) 0c cooling:0/0x0
-----BOARD-1-----
PSU[UNKNOWN]: 0->216w[216 216 216] (->216w[216 216 216]) (lim=220) 0c cooling:0/0x0
-----BOARD-2-----
PSU[UNKNOWN]: 0->209w[209 209 209] (->209w[209 209 209]) (lim=220) 0c cooling:0/0x0
-----BOARD-3-----
PSU[UNKNOWN]: 0->215w[215 215 215] (->215w[215 215 215]) (lim=220) 0c cooling:0/0x0
LOOP[0] ON TO:0
 0: DC2DC/1/:[vlt1:705 vlt2:709(DCl:794 Tl:794 Ul:709) 86W 122A  52c] ASIC:[ 85c (125c) 935hz(BL: 935)   82 (E:193) F:0 L:0]
 1: DC2DC/1/:[vlt1:705 vlt2:709(DCl:794 Tl:794 Ul:709) 88W 124A  71c] ASIC:[ 85c (125c) 935hz(BL: 935)   64 (E:193) F:0 L:0]
LOOP[1] ON TO:0
 2: DC2DC/1/:[vlt1:691 vlt2:695(DCl:794 Tl:794 Ul:709) 89W 128A  80c] ASIC:[100c (125c) 965hz(BL: 965)   81 (E:193) F:0 L:0]
 3: DC2DC/1/:[vlt1:693 vlt2:698(DCl:794 Tl:794 Ul:709) 85W 123A  88c] ASIC:[ 85c (125c) 930hz(BL: 930)   89 (E:193) F:0 L:0]
LOOP[2] ON TO:0
 4: DC2DC/1/:[vlt1:705 vlt2:709(DCl:794 Tl:794 Ul:709) 85W 120A  48c] ASIC:[ 85c (125c) 915hz(BL: 915)   78 (E:193) F:0 L:0]
 5: DC2DC/1/:[vlt1:705 vlt2:709(DCl:794 Tl:794 Ul:709) 83W 117A  62c] ASIC:[ 85c (125c) 885hz(BL: 885)   85 (E:193) F:0 L:0]
LOOP[3] ON TO:0
 6: DC2DC/1/:[vlt1:708 vlt2:709(DCl:794 Tl:794 Ul:709) 88W 125A  68c] ASIC:[ 85c (125c) 925hz(BL: 925)   88 (E:193) F:0 L:0]
 7: DC2DC/1/:[vlt1:703 vlt2:709(DCl:794 Tl:794 Ul:709) 85W 120A  75c] ASIC:[ 85c (125c) 915hz(BL: 915)   75 (E:193) F:0 L:0]

[H:HW:1429Gh,W:692,L:0,A:8,MMtmp:0 TMP:(21)=>=>=>(67,59)]
Pushed 28 jobs , in HW queue 4 jobs (sw:1, hw:1)!
min:43 wins:642[this/last min:23/26] bist-fail:27, hw-err:0
leading-zeroes:42 idle promils[s/m]:0/0, rate:1817gh/s asic-count:280 (wins:11+12)
Fan:40, conseq:200
AC2DC BAD: 0 0
R/NR: 312/0
RTF asics: 0
FET: 0:9 1:9
 0 restarted      0 reset          0 reset2         0 fake_wins
 0 stuck_bist     0 low_power      0 stuck_pll      0 runtime_dsble
 0 purge_queue    0 read_timeouts  0 dc2dc_i2c       0 read_tmout2    0 read_crptn
 0 purge_queue3   0 bad_idle
 0 err_murata
Adapter queues: rsp=3, req=20

[huffdaddy5]

To compare to what I would make in a month underclocked down to 0.650V @ 635W @ 1126GH/s @ $0.098/Kw (0.56W/GH). I would make $149 worth of BTC, spend $39 on electric, and profit $110. Compare that more efficient setup (0.56W/GH), to a less efficient setup 957W/1429GH = 0.66W/GH and I profit $26/month more on the less efficient setup.

[johnyj]

To compare to what I would make in a month underclocked down to 0.650V @ 635W @ 1126GH/s @ $0.098/Kw (0.56W/GH). I would make $149 worth of BTC, spend $39 on electric, and profit $110. Compare that more efficient setup (0.56W/GH), to a less efficient setup 957W/1429GH = 0.66W/GH and I profit $26/month more on the less efficient setup.

My fan is always set to 20, and the underclocked temp is also much lower. Underclock is to squeeze more hashing power into a limited electricity capacity, thus increase the amount of bitcoin harvested for a given power usage, not to make quick fiat money profit

[Newar]

The cooling is sufficient for the first two ASICs, but it gets worse and worse for each ASICs further back, so adding a fan from top of the box can help a lot, unfortunately that means you have to cut a hole on the top. The best solution would be getting individual intake channel for each ASIC, but almost impossible to do due to the compact design of the box

Probably best to take them out of the box altogether and mount fans directly on top of the heatsinks. Sort of what Enterpoint did with the CM1.

Am I right in guessing that the PCB is approx. 120mmx240mm?

[johnyj]

The cooling is sufficient for the first two ASICs, but it gets worse and worse for each ASICs further back, so adding a fan from top of the box can help a lot, unfortunately that means you have to cut a hole on the top. The best solution would be getting individual intake channel for each ASIC, but almost impossible to do due to the compact design of the box

Probably best to take them out of the box altogether and mount fans directly on top of the heatsinks. Sort of what Enterpoint did with the CM1.

Am I right in guessing that the PCB is approx. 120mmx240mm?

130x310, if you take it out, you should also cool the back side of the board, maybe a better way is to use two fans blow from both ends, and leave the cover open to let the heat out, but where to put the controller board could be tricky

[johnyj]

Grill down!    I hung the cutted honey comb grill piece in front of the exhaust fan, and it is blown away by a quite large force, so remove it will improve the airflow for sure. And the hiss noise is gone



I can fit a fan wire grill to increase safety, but not a big deal, currently just leave it open (easy to clean the fan from dust )

[Newar]

130x310, if you take it out, you should also cool the back side of the board, maybe a better way is to use two fans blow from both ends, and leave the cover open to let the heat out, but where to put the controller board could be tricky

Thanks for the info.

I would think by leaving the cover open, you'd loose the channel effect to the inner two heat sinks. It's easier for the air to just rise in the big space than to go through the small space of the fins.

Do you think it's possible to turn one board around 180 degrees, so both heat sinks rows would face outward? Then I could blow from the side at each (after cutting holes) and the fan at the end would take care of the cooling of the back of the PCB.

Good effort on the grille! Get the other one too (except PCB support) 

[johnyj]

Made this adapter for using 3rd party PWM fans





However, the adapter might not be needed. After so many improvements made during latest several iterations, now a GT1850 can drive the SP20 at 0.6V without any dangerous temp, given 42 db of noise, which is as quiet as many home PC (My water cooled PC runs at 38db)



Open middle hole, GT1850, 42db, 465W on wall,  975GH under ambient temp of 15c degree. Now it is really a green miner with a quiet fan  

[johnyj]

130x310, if you take it out, you should also cool the back side of the board, maybe a better way is to use two fans blow from both ends, and leave the cover open to let the heat out, but where to put the controller board could be tricky

Thanks for the info.

I would think by leaving the cover open, you'd loose the channel effect to the inner two heat sinks. It's easier for the air to just rise in the big space than to go through the small space of the fins.

Do you think it's possible to turn one board around 180 degrees, so both heat sinks rows would face outward? Then I could blow from the side at each (after cutting holes) and the fan at the end would take care of the cooling of the back of the PCB.

Good effort on the grille! Get the other one too (except PCB support) 

I thought about adding two holes in the bottom of the case, just before the second bottom row of heatsinks, but that's too much work, and the increase in total intake surface will reduce the airflow speed for each intakes,  so I just use the original case design to cool the last set of ASICs, it is enough good in practice (Thanks god they have two holes originally designed to fit those cables, it suits the purpose well)

[raskul]

Grill down!    I hung the cutted honey comb grill piece in front of the exhaust fan, and it is blown way by a quite large force, so remove it will improve the airflow for sure. And the hiss noise is gone

http://photo.mystisland.org/sp20/sp20_26.jpg

I can fit a fan wire grill to increase safety, but not a big deal, currently just leave it open (easy to clean the fan from dust )

this is really interesting... does it improve the airflow at all? is there a way you can measure it?

[johnyj]

Grill down!    I hung the cutted honey comb grill piece in front of the exhaust fan, and it is blown way by a quite large force, so remove it will improve the airflow for sure. And the hiss noise is gone

http://photo.mystisland.org/sp20/sp20_26.jpg

I can fit a fan wire grill to increase safety, but not a big deal, currently just leave it open (easy to clean the fan from dust )

this is really interesting... does it improve the airflow at all? is there a way you can measure it?

There are reviews analyzed different types of grille and some of them said that a honey comb grill will give 10% less airflow. I can feel that honey comb grill obviously give resistance to air flow. While I don't feel any significant resistance if I hang a wire grill at the same place

[Biffa]

Grill down!    I hung the cutted honey comb grill piece in front of the exhaust fan, and it is blown way by a quite large force, so remove it will improve the airflow for sure. And the hiss noise is gone

I can fit a fan wire grill to increase safety, but not a big deal, currently just leave it open (easy to clean the fan from dust )

I did think of that, it harks back to my watercooling days, but effect on resale value turned me off it.

[spiccioli]

 While I don't feel any significant resistance if I hang a wire grill at the same place

I would not leave such a powerfull fan open, it can seriously injure a finger.

spiccioli

[Syke]

I would not leave such a powerfull fan open, it can seriously injure a finger.

While it could hurt, it is an exhaust fan. Far less dangerous than an intake fan.

[raskul]

I would not leave such a powerfull fan open, it can seriously injure a finger.

While it could hurt, it is an exhaust fan. Far less dangerous than an intake fan.

beat me to it.. the blades point inwards... i'd still make sure it was away from anywhere that the cat could get nosey about it.

[johnyj]

Turns out I still have to pay 60 euro for the import tax and some extra charge to DHL 

The PWM adapter did not work at first, since the wire on the stock fan socket is different: The power on that socket is negative 12V. In order to run a PWM fan, you have to switch the position of the power and ground line on the fan connector, which makes the connector wiring color looks different than normal PWM connectors. This first photo shows the difference



The Everflow fan on this photo has 9 blades, but it is actually noisier than delta fan due to it is only 28mm in depth. With a delta AFC1212DE installed, at 20% speed, the DC temp never goes above 60c degree, which is my comfortable zone. The noise goes up to 54db at one meter distance, still acceptable, and a great improvement over stock fan's 68 db at 20% speed

[johnyj]

A new record: Ambient temp 5c degree, 0.6/0.605 setting, 897GH, consumes 345W at wall, means 0.385W/GH efficiency

At very low temp, the normal 0.59/0.6V setting can not start all the loops, must raise it to 0.6/0.605V to get all the loops running, but the result is quite respectable

[Syke]

A new record: Ambient temp 5c degree, 0.6/0.605 setting, 897GH, consumes 345W at wall, means 0.385W/GH efficiency

At very low temp, the normal 0.59/0.6V setting can not start all the loops, must raise it to 0.6/0.605V to get all the loops running, but the result is quite respectable

http://photo.mystisland.org/sp20/sp20_lowest.png

Impressive. Got a screenshot of the ASIC Status page?

[Guy Corem]

A new record: Ambient temp 5c degree, 0.6/0.605 setting, 897GH, consumes 345W at wall, means 0.385W/GH efficiency

At very low temp, the normal 0.59/0.6V setting can not start all the loops, must raise it to 0.6/0.605V to get all the loops running, but the result is quite respectable

http://photo.mystisland.org/sp20/sp20_lowest.png

Impressive. Got a screenshot of the ASIC Status page?

Indeed, impressive.