Second PSU crapped out after just over a month

[dragonmike]

Just thought I'd share.

Rigs config: 7x RX 570, 2x 750W PSU
Got 2 of these rigs.

First PSU crapped out right from the start. It was an old XFX I had, and it didn't withstand the load at all. Replaced with EVGA 750GQ (80+ Gold).
This rig is still going strong with 2x EVGA 750GQ's. Cards are undervolted, total draw is approx 1160W at the wall.

Second rig has one old XFX 750W (still going strong) and one EVGA 750GQ that was new a month ago. It crapped out last night. I could boot into Windows but impossible to get any mining load on it, it would just turn itself right off (taking 4 GPUs and the system down with it).

Fortunately I had a spare (same unit) that I put in now. Been chugging for half an hour, touch wood that it will hold for a while.

Total load on that unit is approx 620W, which is 83% of 750W. Being 80+ Gold, it should be at least 92% efficient at full load. I will admit it's cutting it close, but nevertheless it shouldn't crap out after just a month of use. The old unit will be RMA'd to EVGA.

Don't do like me. Don't assume "it will be fine". Bite the bullet, spend the extra 75 bucks per PSU and get more headroom. Crazy how much power delivery is important on mining rigs.

[sc8nt4u]

Yup, learned the first time I dived into GPU mining bitcoin. A Xion 1300W didn't last more than 3 months. I now run my 8x 580 on 2x EVGA T2 750W.

[dragonmike]

Out of interest, did you get a replacement unit through RMA? Thinkng I could just sell the new unit if they replace the old one... And buy something a bit sturdier for when the next PSU gives up...

[sc8nt4u]

Out of interest, did you get a replacement unit through RMA? Thinkng I could just sell the new unit if they replace the old one... And buy something a bit sturdier for when the next PSU gives up...

Yup, got a new one through RMA. Sold the PSU once I got it back from RMA.

[Nokia555]

Always get a gold one for mining, those cheap PSU-s will die pretty quickly yeah. But why didn't you take one EVGA Gold 1300W? http://mylifegadgets.com/EVGAGOLD

[64dimensions]

If you are in the US and running off of 120V receptacles, check your outlets with one of these: http://www.homedepot.com/p/Klein-Tools-GFCI-Receptacle-Tester-RT210/206517824.

Any chance that the room that your miners are in is carpeted? Would you generate any static electricity walking around in it?

[mcturkey]

Don't use cheap PSUs, and don't use dual PSUs on one system if you can possibly help it.  Unless you're just making use of some high quality, lower wattage PSUs you had already, there is absolutely no reason to be using more than one PSU in a rig.  I have never seen a pair of PSUs that cost less than a comparable wattage single PSU of the same quality and efficiency.

If you still insist on using dual PSUs, keep them electrically isolated from each other - a GPU and riser combo should only receive power from a single PSU, never split.  Same for the motherboard.  Use only powered, USB-connected risers -- never the ribbon cable ones.  Failure to isolate can kill even the highest quality power supplies.

With a 7-GPU rig, you're making $35+ per day.  Saving $50 by using a cheaper PSU is pointless if you end up having to RMA it or wait for a replacement.

[dragonmike]

Don't use cheap PSUs, and don't use dual PSUs on one system if you can possibly help it.  Unless you're just making use of some high quality, lower wattage PSUs you had already, there is absolutely no reason to be using more than one PSU in a rig.  I have never seen a pair of PSUs that cost less than a comparable wattage single PSU of the same quality and efficiency.

If you still insist on using dual PSUs, keep them electrically isolated from each other - a GPU and riser combo should only receive power from a single PSU, never split.  Same for the motherboard.  Use only powered, USB-connected risers -- never the ribbon cable ones.  Failure to isolate can kill even the highest quality power supplies.

With a 7-GPU rig, you're making $35+ per day.  Saving $50 by using a cheaper PSU is pointless if you end up having to RMA it or wait for a replacement.

I agree on most of the above - it shall be noted that my 750W PSUs are all EVGA 80+ GOLD so not supposed to be crap. Also these cost £90 each and an equivalent 1350 or 1500 cost closer to £300. So yes, I went for the cheaper solution, but definitely not for a low quality one. Just arguably a little too weak.

Not on carpet, no. Wooden frame on wood planks in the attic. They are all plugged into the same high quality belkin socket extender however.