[Review] Spondoolies SP20 review - A Green miner with a Loud fan - page 7.

klondike_bar

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Quote from: Syke on December 18, 2014, 07:40:14 PM

Quote from: Guy Corem on December 18, 2014, 06:42:59 PM

The second set of chips get hit with warmer air, but not +40C hotter.

Ok, my intake is about 40c, and exhaust is about 80c, so the back chips are getting +20c air. It significant enough that they are downclocked 200 MHz as a result of the hot air from the front chips.

why is your intake temperature so high? thats the problem. Ideal intake is about 15-30C and ideal outlet is 65-75C

johnyj

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Quote from: mavericklm on December 19, 2014, 03:03:28 AM

Quote

This fan consumes 3A at its maximum output, so should be as powerful as the stock fan. However, it has 7 blades instead of 5 on the stock fan, so the noise performance is much better. In principle any 7-blades 120x38mm delta fan could dramatically reduce the noise

Noted!

Very nice drop in decibels!

I just tested with stopper moved out of the box, even without the vibration noise, stock fan at 20% speed still generate 68 db, maybe because of the lowest operating voltage for stock fan is 7 volt. But its cooling effect is strong, even at 27c at frond end, the back end temp never goes above 50c

And with GT1850, after a while I opened the case, some part of the case is extremely hot, especially the last ASIC heatsink, definitely over 100c, dangerous

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Quote

This fan consumes 3A at its maximum output, so should be as powerful as the stock fan. However, it has 7 blades instead of 5 on the stock fan, so the noise performance is much better. In principle any 7-blades 120x38mm delta fan could dramatically reduce the noise

Noted!

Very nice drop in decibels!

johnyj

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Record! Noise down to 48 db. Now even without door closed, I can barely hear it 10 meters away. Accomplished by previous low speed fan king GT1850

At ambient temperature of 14c, it can keep the back end temp at 60c. But now the difference between the lowest temp DC module and highest temp DC module is as high as 30 degree (33/66), the air flow is not fast enough to cool the second ASIC module in the channel.

At 22c degree ambient, back end reached 68c, now two of the ASICs reached 105c. It seems with this weaker fan, even at 0.6v you can not run at an ambient temp over 25c degree

So delta fan is still the better choice

Another issue: The metal ASIC board stopper under the fan is so high that it has a direct contact with the fan, that's the reason adding rubber pin for the fan did not remove the vibration noise from the case. I removed that stopper totally and the vibration noise is gone (When fully assembled, ASIC boards are fixed by other screws, even without this stopper they won't move)

johnyj

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Success! Lowered noise to 60 db! Now it is not audible anymore when the door is closed. It is a comfortable level even when I'm sitting beside the rig, just feels like in a server hall, not industry warehouse with lots of machinery. The room's ambient noise is 33 db before running SP20

After 15 minutes of running, with a front temp of 25c degree, I get 60c degree for back temp, and none of the ASICs reached minimal watching threshold of 85c degree

The test method learned from Biffa:

The fan speed regulator is running at 5V, but with such a large load, it gets very hot. I hang it up at the exhaust to cool it, but will try to make the adapter to utilize the PWM socket on board later

Hero of the day: Delta AFC1212DE.

This fan consumes 3A at its maximum output, so should be as powerful as the stock fan. However, it has 7 blades instead of 5 on the stock fan, so the noise performance is much better. In principle any 7-blades 120x38mm delta fan could dramatically reduce the noise

Syke

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Quote from: johnyj on December 18, 2014, 08:12:24 PM

I just checked the ASIC stats page, on my underclocked unit at 0.6V, the difference between different ASIC chips is maximum 10 degrees

Yeah, they're great when underclocked.

johnyj

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Quote from: Syke on December 18, 2014, 07:40:14 PM

Quote from: Guy Corem on December 18, 2014, 06:42:59 PM

The second set of chips get hit with warmer air, but not +40C hotter.

Ok, my intake is about 40c, and exhaust is about 80c, so the back chips are getting +20c air. It significant enough that they are downclocked 200 MHz as a result of the hot air from the front chips.

Maybe you can do some air channel to send some cold air into the back row of the heat sink

I just checked the ASIC stats page, on my underclocked unit at 0.6V, the difference between different ASIC chips is maximum 10 degrees

johnyj

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A high-end solution would be vapor chamber based heat sink, but it is really a pain to recondition all of the 8 chips even if you have the new heat sink with the right size/mounting. I have not find a good way to remove those hardened glue without risking hurt the die under the heat sink. I will just leave the original heat sinks as they are

The difficulty trend is down, it is worth to do some tweaking when operating life expectancy is increasing

Guy Corem

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Quote from: Syke on December 18, 2014, 07:40:14 PM

Quote from: Guy Corem on December 18, 2014, 06:42:59 PM

The second set of chips get hit with warmer air, but not +40C hotter.

Ok, my intake is about 40c, and exhaust is about 80c, so the back chips are getting +20c air. It significant enough that they are downclocked 200 MHz as a result of the hot air from the front chips.

Every system has tradeoffs. In the SP3x series as well, the cooling solution isn't symmetric.

In case of the SP10, with the shared heatsink, the cooling was more symmetric.

The RockerBox ASICa with the FCBGA package aren't suitable for shared economocial heatsink. Mechanical stress, etc.

The system may be tweaked for better results. The entire software is open source as well.

Disclaimer: Modifying will cause a warranty lost.

johnyj

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Quote from: Dexter770221 on December 18, 2014, 04:47:05 AM

Everyone that done review have hashrate dip to 0 in 1day hashspeed chart. In your case was the same? This units resets itself in 1 day periods?

I have done two session (some modification and tweaking in between), the latest one is 20 hours but have not experienced any drop in performance

Syke

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Quote from: Guy Corem on December 18, 2014, 06:42:59 PM

The second set of chips get hit with warmer air, but not +40C hotter.

Ok, my intake is about 40c, and exhaust is about 80c, so the back chips are getting +20c air. It significant enough that they are downclocked 200 MHz as a result of the hot air from the front chips.

the joint

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Quote from: Dexter770221 on December 18, 2014, 04:47:05 AM

Everyone that done review have hashrate dip to 0 in 1day hashspeed chart. In your case was the same? This units resets itself in 1 day periods?

I can't speak for others, but the stats I posted in my review were accumulated while leasing my rig out because of the Paycoin frenzy. Any significant drop in hashrate was likely the result of renters switching pools or accidentally entering invalid pool mining credentials.

klondike_bar

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Quote from: Guy Corem on December 18, 2014, 06:42:59 PM

Quote from: Syke on December 18, 2014, 06:39:37 PM

Quote from: klondike_bar on December 18, 2014, 06:11:05 PM

not really when you consider that pushing it for an extra 100GH will increase the overall power draw by 100W - you make the machine much louder and if unless you pay <$0.10/kwh its only amounts to a few extra dollars of profit. hence why a lot of people are running this 1.7TH/1.1kW device at 1.3TH/0.8kW

With better cooling you get better efficiency and lower noise. The problem with the SP20 is the unequal cooling of the chips. The second set of chips gets hit with air that's +40c hotter. Cool them with ambient air and you can lower their voltage and increase the efficiency.

The second set of chips get hit with warmer air, but not +40C hotter.

+1 better cooling would increase efficiency a bit, but not with much effect. A larger heatsink would allow slower-moving fans which would be nice, but IMO theres not much purpose in pushing them to the absolute limit unless you have cheap electricity, and even then the SP20 drives the chips quite high.

(8 chips in SP20 = 1.7TH) vs (30 chips in SP35 = 5.5 TH) If the SP3X series ran all 30 chips at the same power as the SP20 you would see it achieve around 6.3TH (similar to the original claims). However, that would use around 4.4kW at the wall. Instead, the SP35 does 5.5TH/3.6kW and the SP31 does 4.7TH/2.8kW. The hashrate gain is at about 1w/GH, which doesnt make sense for a lot of users right now

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Quote from: Syke on December 18, 2014, 06:39:37 PM

Quote from: klondike_bar on December 18, 2014, 06:11:05 PM

not really when you consider that pushing it for an extra 100GH will increase the overall power draw by 100W - you make the machine much louder and if unless you pay <$0.10/kwh its only amounts to a few extra dollars of profit. hence why a lot of people are running this 1.7TH/1.1kW device at 1.3TH/0.8kW

With better cooling you get better efficiency and lower noise. The problem with the SP20 is the unequal cooling of the chips. The second set of chips gets hit with air that's +40c hotter. Cool them with ambient air and you can lower their voltage and increase the efficiency.

The second set of chips get hit with warmer air, but not +40C hotter.

Syke

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Quote from: klondike_bar on December 18, 2014, 06:11:05 PM

not really when you consider that pushing it for an extra 100GH will increase the overall power draw by 100W - you make the machine much louder and if unless you pay <$0.10/kwh its only amounts to a few extra dollars of profit. hence why a lot of people are running this 1.7TH/1.1kW device at 1.3TH/0.8kW

With better cooling you get better efficiency and lower noise. The problem with the SP20 is the unequal cooling of the chips. The second set of chips gets hit with air that's +40c hotter. Cool them with ambient air and you can lower their voltage and increase the efficiency.

klondike_bar

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Quote from: Syke on December 18, 2014, 05:36:58 PM

Quote from: klondike_bar on December 18, 2014, 05:31:20 PM

not worth it - as it is most users are underclocking anyways, so putting in $50 worth of hiher quality heatsinks serves minimal benefit.

Let's go with $50. I'm pretty sure a better cooler would get at least 100 GH/s better performance. That's $12/mo extra. You make up the difference in cost in 4 months. Better performance, better efficiency, lower noise, longer life. At $50 it's an easy win.

not really when you consider that pushing it for an extra 100GH will increase the overall power draw by 100W - you make the machine much louder and if unless you pay <$0.10/kwh its only amounts to a few extra dollars of profit. hence why a lot of people are running this 1.7TH/1.1kW device at 1.3TH/0.8kW

Syke

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Quote from: klondike_bar on December 18, 2014, 05:31:20 PM

not worth it - as it is most users are underclocking anyways, so putting in $50 worth of hiher quality heatsinks serves minimal benefit.

Let's go with $50. I'm pretty sure a better cooler would get at least 100 GH/s better performance. That's $12/mo extra. You make up the difference in cost in 4 months. Better performance, better efficiency, lower noise, longer life. At $50 it's an easy win.

klondike_bar

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Quote from: Syke on December 18, 2014, 05:13:06 PM

Quote from: johnyj on December 18, 2014, 03:12:20 PM

I remember that the GPU mining efficient king HD 5970 had 2 GPUs, and the cooling element combined two copper core in one assembly

http://i2.rozetka.ua/goods/2159/arctic_cooling_accelero_xtreme_5970_2159447.jpg

That heat pipe setup is nice. The regular 5970 passes the air across both GPUs:

Quote from: johnyj on December 18, 2014, 03:12:20 PM

Given the design of SP20's board, such design is not suitable, but at least a heatpipe element can be mounted on each of them, and I think the cost will also be low if mass produced

Maybe, those who prefer lower noise could order upgraded heat pipe heat sink to their SP20, and those heat sink can be reused on future spondoolies products (compatible mounting on future miners)

A heat-piped SP20 would be great.

not worth it - as it is most users are underclocking anyways, so putting in $50 worth of hiher quality heatsinks serves minimal benefit.

Syke

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Quote from: johnyj on December 18, 2014, 03:12:20 PM

I remember that the GPU mining efficient king HD 5970 had 2 GPUs, and the cooling element combined two copper core in one assembly

http://i2.rozetka.ua/goods/2159/arctic_cooling_accelero_xtreme_5970_2159447.jpg

That heat pipe setup is nice. The regular 5970 passes the air across both GPUs:

Quote from: johnyj on December 18, 2014, 03:12:20 PM

Given the design of SP20's board, such design is not suitable, but at least a heatpipe element can be mounted on each of them, and I think the cost will also be low if mass produced

Maybe, those who prefer lower noise could order upgraded heat pipe heat sink to their SP20, and those heat sink can be reused on future spondoolies products (compatible mounting on future miners)

A heat-piped SP20 would be great.

johnyj

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Quote from: Syke on December 18, 2014, 02:20:17 PM

Quote from: johnyj on December 18, 2014, 02:10:13 PM

The size of Rockerbox chip is the same as GPU, and it is 28nm! Modern GPU typically employ a large heatpiped heat sink with lots of fins for silent operation, but that is aiming for at least 5 years life expectancy. When there are 4 such GPUs on one single board, no simple cooling solution except lots of air flow can dissipate those heat

It's more the layout that's the problem. The airflow passes over 1 chip and goes +40c, then it passes over the other chip and goes another +40c. The second chip is baked by the first chip.

I remember that the GPU mining efficient king HD 5970 had 2 GPUs, and the cooling element combined two copper core in one assembly

Given the design of SP20's board, such design is not suitable, but at least a heatpipe element can be mounted on each of them, and I think the cost will also be low if mass produced

Maybe, those who prefer lower noise could order upgraded heat pipe heat sink to their SP20, and those heat sink can be reused on future spondoolies products (compatible mounting on future miners)

Topic: [Review] Spondoolies SP20 review - A Green miner with a Loud fan - page 7. (Read 21001 times)