Nice setup there.

Absolutely 924 is a huge overclock.

I have a 188 CFM fan blowing over the Moonlanders.  Works great - it's an inline tube fan generally used in marijuana grow houses.  Has a four inch outlet that comfortably accomodates my four Landers.  Heat sink temps stay about twenty degrees above room ambient temperature.

I spent a bunch of time diddling voltages and ended up with these as most stable.  Hard error rate is ~.62%.  I used to stop them and power cycle each morning but I have been curious as to exactly how stable these really are.  So far, they've now been running six days and 13.5 hours without failing or any increase in error rates.

Device 03/COM 3/Port_#0004.Hub_#0003/vcore=.890/vmem=.908/Clock=924
Device 04/COM 4/Port_#0001.Hub_#0003/vcore=.891/vmem=.907/Clock=924
Device 01/COM 5/Port_#0003.Hub_#0005/vcore=.890/vmem=.907/Clock=924
Device 02/COM 6/Port_#0002.Hub_#0004/vcore=.891/vmem=.907/Clock=924

I suspect that the BrovSS 10 port hub I'm using has something to do with that.  It actually does supply 2.1 amps per port.  It is also connected through my UPS, so it gets stable filtered power input regulated to 120VAC plus or minus three volts.

I also upped the port speed in Device Manager to 38400bps from the default 9600bps.