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

[johnyj]

And the only problem for home mining is its noise, just like a vacuum cleaning running, it is impossible to run at home. With even one door closed I can hear it clearly far away. So either you run it in a specialized garage/mining farm, or you have to take some modification for the cooling system. I will take it apart tomorrow to see what I can do with it

I suppose that the original fan deliver a huge amount of airflow like 200 CFM maximum, but when heavily under clocked, maybe a general low CFM/noise fan can deal with the heat

I'm personally thinking of buying a better fan and swapping it in, wonder if that'll make a huge difference?

Just heats up quicker.

The heat sink on SP20 is just entry level plain aluminum heat sink, they don't have huge surface area like those heat pipe heat sink with many thin aluminum fins, so the airflow must be very high to reduce the surface temperature

I just measured 20% fan speed noise at 1 meter away with my sound meter app, it is still 67db, and I personal feel is close to in car noise on highway (70+-db)

[philipma1957]

Thank you for the review.

Thank you too for letting us review such a great product!

Before I started to operate SP20, I thought this kind of products are just like many other miners on the market: You stack them up in a mining farm and pay lots of electricity and cooling cost, and sell the coins to cover these cost, and bring down the bitcoin exchange rate during the process. I even planned to give it to friends who are interested in bitcoin after this review

But after seeing the stunning efficiency of this miner, I'm very impressed. I had a feeling that the old good mining time is back: With this unit running at 500W, the electricity cost is neglectable, so anyone can just hold on to all the mined coins without selling a bit

Now I'm very interested to run it for an extensive period of time with a modified cooling solution

so far no  one has found a better fan solution.  I do think if you fully tear the machine down it could be cooled quieter.  

  Right now I have six.
  I wish I ordered more.  
  I would try lower downclock then my 1350gh and 750 watts.  
  your review means my 6 x 750 watt = 4.5kwatts and 6 x 1350 = 8100gh  could read
  6 x 440 watts = 2.6 kwatts and 6 x 940 = 5640gh

I can do more then the 6.  I will look forward to any idea you have to manage  noise.

[Biffa]

Thank you for the review.

Thank you too for letting us review such a great product!

Before I started to operate SP20, I thought this kind of products are just like many other miners on the market: You stack them up in a mining farm and pay lots of electricity and cooling cost, and sell the coins to cover these cost, and bring down the bitcoin exchange rate during the process. I even planned to give it to friends who are interested in bitcoin after this review

But after seeing the stunning efficiency of this miner, I'm very impressed. I had a feeling that the old good mining time is back: With this unit running at 500W, the electricity cost is neglectable, so anyone can just hold on to all the mined coins without selling a bit

Now I'm very interested to run it for an extensive period of time with a modified cooling solution

so far no  one has found a better fan solution.  I do think if you fully tear the machine down it could be cooled quieter.  

  Right now I have six.
  I wish I ordered more.  
  I would try lower downclock then my 1350gh and 750 watts.  
  your review means my 6 x 750 watt = 4.5kwatts and 6 x 1350 = 8100gh  could read
  6 x 440 watts = 2.6 kwatts and 6 x 940 = 5640gh

I can do more then the 6.  I will look forward to any idea you have to manage  noise.

I think the only way to cool it down better without lowering ambient is to take it out of the case and strap fans or point fans at the boards individually.

There is however one problem handling the boards. The heatsinks are only secured in two diagonally opposite locations, and it only takes a small bit of pressure to move the heatsink off the die which breaks the TIM seal between the die and the heatsink, it also may risk crushing or damaging the die, although that hasn't happened to me yet. But I think once you disturb the TIM seal it can affect temps.

[johnyj]

Open the case

[johnyj]

Controller board

[johnyj]

It uses a channel design to cool both the heat sink and the VRM on the back of the board, so an open case cooling solution might not be as optimal

[johnyj]

Left is a replacement fan I planned to put in. Unfortunately they don't have the same socket type and even the pin out is different. If I want to install other PWM fans, I would have to take the original plug and wire, solder on a PWM socket to make an adaptor

[johnyj]

4 ASIC chips per board

[johnyj]

The heat sink is hold tight not only by 2 screws on each corner, but also two drop of glue on each side. The glue is very hard, which makes the removal and refitting of the heat sink more difficult: you have to cut the glue first , and later when you install it back, you need some similar glue that can tolerate high temperature of the heat sink, a normal heat glue gun will not work

[johnyj]

The heat sink uses a copper plate mounted together with aluminum heat sink that you could see on CPUs 10-20 years ago, they are joined together with some white thermal grease (which is not quality thermal compound). And the large contact surface of the copper plate does not really help since the contact surface with ASIC is small. You can see there are some thermal grease on the ASIC chip capacitors, and they are still wet as I touch them with a needle

If you re-condition the heat sink components and replace the white thermal grease with MX4 or even liquid metal on ASIC surfaces, that could bring down the temp 5-10 degrees. But due to the weak heat sink, it still can't carry out the heat enough fast unless you have huge amount of airflow passing through

It is a pitty that a modern 28nm processor only equipped with a heat sink that is decades ago, without heatpipe, without many thin finns. This in turn caused the annoying noise issue

[johnyj]

Back of the ASIC board, clean layout

[johnyj]

I only replaced the metal screws with rubber pins, it does not really make a lot of difference, noise at 1 meter (20% fan) dropped from 67 db to 66db. To replace with my own fan, an adapter is needed, do it later

[Biffa]

To test different fans this is what I did:

[Puppet]

It uses a channel design to cool both the heat sink and the VRM on the back of the board, so an open case cooling solution might not be as optimal

Im curious, does the underside of the board (bottom of  picture) get warm at all? Looking at the design, I would think most air pressure will escape there,  following the path of least resistance, and relatively little air will flow particularly over the top heatsinks. Id try channeling the air by blocking most or all of the clearance to the underside and using a fan with perhaps lower CFM but high static pressure.

[Dexter770221]

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?

[johnyj]

To test different fans this is what I did:

That's a nice idea!   You can even install a fan speed regulator outside the case

Have you tried GT1850 with the SP20 set to 0.6v?

[johnyj]

Im curious, does the underside of the board (bottom of  picture) get warm at all? Looking at the design, I would think most air pressure will escape there,  following the path of least resistance, and relatively little air will flow particularly over the top heatsinks. Id try channeling the air by blocking most or all of the clearance to the underside and using a fan with perhaps lower CFM but high static pressure.

Exactly, the construction reminds me of Avalon gen 1, you can narrow down the other channel to increase the air flow, but I think the effect will be minimal, since that original fan is a 2A high static pressure fan. The whole case is very cool, there is no direct contact between the heat sinks and the case

In my experience, the optimal output of 120x38mm fan is around 120CFM, where noises are still tolerable. Above that, you will dramatically increase the noise without too much improvement of airflow, a 200 CFM fan would sound 4x more noisy than a 120 CFM fan

[wpgdeez]

Looks like a lot of cost cutting has been done to maximize profit.

[Guy Corem]

Looks like a lot of cost cutting has been done to maximize profit.

I wish. Not true.

[Biffa]

To test different fans this is what I did:

That's a nice idea!   You can even install a fan speed regulator outside the case

Have you tried GT1850 with the SP20 set to 0.6v?

Yes, they just don't push enough air.

I've tried the GT1850 and up to the 4250