TechnoBit DICE Bitcoin ASIC Cooling Performance

We are still playing with our hardware latest toy, the small TechnoBit DICE Bitcoin ASIC miner and today we were checking the cooling performance of the device. When we first saw the announcement the DICE was supposed to be a very silent miner as per the official specifications that stated (and still state) “Noise: ~20 DB at 25 °C ambient temperature”, however the moment we have turned on the unit a few days ago we knew this promise was not kept. If the noise level was just about 20 decibels than the DICE should’ve been so quiet that you would hardly know it is present and working in a quiet room. The reality is quite different though, our sound level meter has detected a noise level of almost 50 dBA and this is really quite noisy and a far cry from the promised noise. So we just had to take apart the device to see what fan it is using and also test to see if the case of the miner could be the culprit that is responsible for the very noisy operation of the DICE Bitcoin ASIC…

When we have opened the case of the ASIC miner we’ve discovered that the cooling fan used inside is a 92mm Evercool EC9225M12CA, a mid range fan that does 2200 rpm with about 1.8W of power usage. Apparently the fan itself was sufficient to cool the miner with its 39.35 CFM of air flow and interestingly enough the specifications of the fan do say less than 25 dBA in terms of noise generated. The fan itself was directly soldered to the pins of the 6-pin PCI-E power connector on the unit, there is no thermal control or variable rpm, it is working at maximum all of the time. Running the miner without its metal casing has show us that it can be quite silent indeed, so the cause of the noise apparently was the metal case of the miner. More specifically the holes at the fan air intake that apparently are responsible for the significant increase of the noise level, so when TechnoBit has promised us a silent Bitcoin ASIC miner they should have modified the case of the device, so that it can really be silent and not the opposite – make a case that will increase the noise level way over what was promised in terms of specifications.

The cooling of the single RockerBox ASIC chip that is at the heart of the DICE miner is sufficiently provided by two large aluminum heatsinks, one on top interfacing with a solid copper block to the ASIC chip and one at the bottom with direct contact to the whole surface of the PCB. There is enough thermal paste in between the heatsinks to provide good heat transfer and the not so powerful cooling fan has no trouble keeping the temperatures low, so that the about 100W of power used at the stock settings are not a problem. The device can also handle a nice boost in performance with some overclocking that is possible via parameters for the ASIC chip voltage and operating frequency, though you should be careful should you decide to clock the unit higher.

In the end we take a look at the operating temperatures of the DICE with the help of a thermal imaging camera, the thermal image you see above shows how hot the top and bottom heatsinks get while the device is working normally. We are getting close to 60 degrees at the top heatsink and a bit over 40 at the bottom at the hottest sports, do note however that the operating temperature of the Bitcoin ASIC chip under the heatsink should be higher with something like 10-20 degrees Celsius over the temperature we have measured on the heatsink. So if you decide to overclock the miner you should proceed with caution and monitor the operating temperatures as the power usage increases along with the hashrate when you increase the operating voltage and frequency of the Bitcoin ASIC chip.