Re: Building Cheap Miners : My "Secret"

The Dell R815s that I got are running rock solid.

Hard to justify the price at this point, though, IMHO -- unless you get a sweet deal.

Well... I have to take that back a bit now.

My power flickered last night thus turning off all my hardware. Came in, turned all the Dells back on... started XMR-STAK on them all & walked off.

Noticed my pool hash-rate never returned to how it was... every one of my R815s is now ~400 H/S slower than they were before the power flickered (1600 H/S vs. 2000 H/S).

I've tried re-booting and even re-compiling XMR-STAK... seems to be permanent ?!

Any ideas ?

Some servers have a bios setting for throttling in the event of a power failure. It's possible it got stuck in that state? Have you tried a full proper power shut down and restart?

I have not done a complete "hard" power off -- I will give that a shot.

Okay tried on two systems. One just a "shut down" then power back on. One with a "shut down" and unplug / replug the system. No effect on either system. Both still doing only 1600 H/S

Apparently this IS, in fact, a thing :

https://community.spiceworks.com/topic/1447342-dell-r820-slow-after-power-outages

So... that being said I'll have to work on them tomorrow when I have some time.

One of the responses in that thread... Seems like it'd be the fastest solution in your case.

Quote

I did discover that if I shut the server all the way down, pull the plugs, wait 10-15 seconds, then plug it back in. After rebooting, it seems to be acting normal again. So what is it about pulling the power OR changing the performance profile that would fix whatever issue is happening?

So... I have tried on 5 systems so far to power off, unplug AC power, AND unplug the CMOS battery -- leave them unplugged long enough to clean out the system with some air. Re-assemble... and start mining. They are all STILL doing only 1600 H/S vs. 2000 H/S before the power flicker.

I have now also tried this from the link :

" I have to go into the BIOS and switch the performance settings from Max Performance to something else, then back. After that, the server performs at lightning speed again. "

Tried on two systems so far -- zero effect.

So... I'm kind of stumped.