Bitmain Antminer R4 ~8.5TH/s at 0.1 W/GH Quiet Home Bitcoin Miner

Had a hiccup on the first one but the vendor send a new one right out. Working great. Great vendor

Worked for a year - then half of the ASIC processors stopped working. Now it is only good for 4.3TH/s. No support. Beware of manufacturer that also mines BTC itself. Embedded throttling software that manufacturer can activate to shut you down.

It's much quieter than the older miners and maintains a steady 8TH/s rate. My reservation about this new design is the fan - it looks like a custom design so when it wears out it will not be easy to replace - on the other hand, it runs at relatively low rpm so hopefully it will last a long time. The R4 software does not allow you to set the clock rate so you have no control over the hash rate, unlike the older miners where you could push the rate up if the environmental conditions allow it. The software also takes a long time ~ two minutes to startup, returning a cryptic error message until it's ready. Occasionally the R4 will drop its hash rate to about 50% but a reboot seems to fix it.My "new" unit ran straight out of the box, it had been well run in prior to shipping judging from the amount of dust and dirt on the heatsinks. I'd guess that it will pa for itself in a year or so.Updated Dec, 2019 - One board died so it's running quietly but it's running fine at half power and warming the room nicely - my reservations about the fan were completely wrong.

https://www.amazon.com/dp/B01N23DI61/ref=cm_cr_ryp_prd_ttl_sol_1

EXCELLENT SERVICE, EXCELLENT PRODUCT, WE RECOMEND IT PROVIDER