I did have the other m20s die. and a m21s
Could you provide more details? how did they die, is it a PSU or dead hash boards? how long did they run for? I know you had great luck with the S17 pro which is against the odds, judging by large sample reviews it's pretty obvious the M21s and the M20 is a lot more robust than all the 17 series of bitmain including the Pro version, this also reflects in the price of these gears, despite being a lot more effienct and newer, the S17 Pro is always either the same price or cheaper than MicroBT gears which also leads to the same conclusion.
With that being said, the reviews between M20s vs M21s are not so clear, but judging the price it seems like the M21 is a lot more reliable.
M20s = $33 per TH
M21s = $34 per TH
keep in mind the M20 is 46w/th vs 60w/th for the M21s, which means the M20s is a lot cheaper than the M21s, this suggests that at least in theory the M20 is more reliable, on a side note, they both use the same PSU.
Okay we have a voltage drop issue at the large farm. One or 2 times a month the voltage drops to 190-195 vs 238. The reason is Verizon a large phone and tele company is a block from the farm/warehouse. This particular Verizon location is the redundant back up to the New York Stock exchange and they test the backup monthly. When the testing the backup it browns us out. 10 -20 minutes. Not a big issue except the psu's will run on almost all the gear and the what's miner psu ends up getting stressed and pulling excess amps to run the gear. So the psu's tend to wear out.
Also the psu was 1 plug not 2 so sometimes we would pop a circuit. It is not so much that the gear was bad as our farm has the voltage issue. Secondary the what's miners are not as heat robust as the s9 or s17 or t17 . In the summer if we get to 95f the hot aisle is really hot 120f. yeah the cool aisle is also 95f. And the what's miner gear would specifically say the room is too hot.
We are in a large ware house in a smaller room. We have over 300kwatts available but can not get enough air into and out of the room.
we feed in 9+10+5 = 24000 cfm and pull out 14+5= 19000 cfm. We burn 125 of the 300 kwatts available.
So the bitmain gear will run on those hot days.
The whatsminer struggled.
We have a second room it does well with gpus only. But it is 10x the size and 1/7 the power used.
