Follow up... question about PDUs amp readings

[jnewsom23]

Morning everybody!

My colo setup is 6 miners +  Cisco SG200-26 Gigabit Ethernet Smart Switch on same rack and other 4 miners are distributed in 2 different racks.  All are connected to the switch where 6 miners are living.  That is 10 total miners.

When any of miners (14th/s) are plugged into PDU with switch they read 7a, but when they are on other 2 PDUs they are reading 10a or above.

I am not 100% why this is happening, but find it strange whenever any of 10 miners are plugged into PDU where switch is they read 7a, but when moved to other 2 racks the PDUs read 10a or above.

Thanks again gentlemen, always appreciated.

[1714157253]

1714157253

[fanatic26]

the s9 should read 6.5 amps or so at 220, so 7 amps is within spec. Is the other PDU 110v maybe and your PSUs are auto switching and pulling a lot more juice?

[jnewsom23]

How can I verify if the 4 PSUs are auto switching?

[fanatic26]

The colo should be able to tell you what kind of power the PDU is providing. The PSU should be auto sensing, if it was not and it was not setup for the proper voltage it would have just blown up.

[jnewsom23]

Will the miners consumer whatever power is given them? 

I asking colo to switch miner set up to 5 & 5 and see if that somehow better distributes the power consumption.

Thanks for input too, always appreciated.

[ccgllc]

Miners consume power based on their technology (typically measured in "nm" (nanometer transistor size) and the frequency they switch those transistors.  Smaller transistors use less power than larger ones, which is why 16nm S9s are more efficient than 28nm S5 technology.  Of course, design changes within a tech level affect power usage as well, which is why S9s are better than S7s.

This is why the faster you run an S9, the more power it requires:  1127W (11.5TH/s batch), 1225W (12.5TH/s batch), 1274W (13TH/s batch), 1323W (13.5TH/s batch), 1372W (14TH/s batch)

Frequency itself is limited by the power requirements and the corresponding heat generated (remember that every watt of power used switching results in a watt of heat being generated), and by the leakage rate of the transistors themselves.   That leakage is why in any given batch of chips, some will run faster than others - over simplified, the leakage is basically caused by small errors in the printing of the transistors.  Better/faster chips have less random errors.  Think of it a bit like ink bleed, or a small hole in a bucket.  If you dump the bucket slowly, you will get a lot of water out of it.  If you dump it faster, the leak caused by the hole becomes more significant.  Thats not a perfect analogy, but hopefully helps.

Bottom line:  No.  Even if you had a 10KW power supply on a 14TH/s S9, it would still only draw about 1.4KW.

[jnewsom23]

!Perfecto!

Thanks.  Makes no sense for me to pay for 10amps+ when not helping me hash faster.  The colo has to figure out ish on their end, bc my miners & psu's are all pulling 7a on 1 rack, but when moved to other racks they say it's reading 10a.  If they can't figure it out, I probably need to move to different place with more expertise and ability to correctly set up the environment.