I have 3 Corsair RM850 powering 6 overclocked antminers. I've noticed that a few of the pci-e wires would get very warm, near where it connects to the psu, so I switched out the wires with brand new replacement wires over a month ago. I'm having the recurring problem again but no more pci-e wires to replace them with. Are the wires getting very warm safe? Should I be concerned? The wires are warm enough that I can only touch it with my hand for about 3 seconds before it feels hot. I've been running the machines for over 2 months now.
WARM cables are OK. HOT CABLES ARE NOT. You want to aim to make your cables COLD/ROOM TEMP. The temp of the cables is directly related to the amount of CURRENT going through them in proportion to the CROSS SECTION OF THE COPPER in the cable.
CHEAP CHINESE cables 99% of the time HAVE SMALLER COPPER WIRE (to keep them cheap) in them than good name bands. But in saying that the "Budget" PSU's that name brands sell also often have these lower copper content cables to save money.
Always remember HOT CABLES COULD = FIRE and most likely a dead miner. (Insulation melts off and causes a short) again though, Good PSU's have Over Current protection and *should* cut off before that.
All of my PSU cables have been upgraded my myself and are ALWAYS stone cold
The Corsair RM850 is a real quality PSU but the cables look to be under sized (the flat ribbon effect is nice for cable management and looks nice but the trade off is that the cables are slightly smaller than what is best)
Just my 2c worth.
As a side note: I hold a cabling licence in Australia so read into that what you will