RM 850w Fan never spins wvwn with 4790k/R9 290

jkteddy77

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Jun 13, 2013
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I just got my 3rd RMA from Corsair. This time they gave me an Rm 850w since the last 3 HX850w I had screamed at me.
This psu is so far silent.... a little too silent maybe?

I have a 4790k that pulls roughly 100w, and a r9 290 that pulls 250w.

I ran Prime95 and Unigine Heaven at the same time, so that my CPU and GPU were maxed out
I should be pulling like 500-600w should I not?
The PSU says on the back that at about 40% load, the fan should start up and start cooling.
I've never seen it spin, not even once. Not even at my computer's start up like my HX-850w's would.
40% = 340w
I KNOW I'm pulling more than that.
What gives? is this common? Is this okay? Anyone have experience with this PSU?
I don't want to have the fan just sit dead if I decide to add another 290 or it overheats after a long gaming session.
 


Have you any experience with this series?

My other concern is heat. Becasue the PSU fan isn't spinning, the outside and top of the PSU is very hot, just radiating heat. It has made my 290 go from its usual 75C to 81C now, in the matter of 30 minutes of gaming.
The Fan has still yet to ever come on
How can I even be sure the fan works at all, I haven't seen it spin under its own power ever, even on startups or shutdowns.

Should I flip the sucker over so the heat doesn't float out of the fan and into may case, or would that trap heat inside the PSU and hurt it since the fan doesn't want to spin?
Like it feels hot, the PSU feels like it is 60C.
My HX-850w was stone cold, even when it spun up to like only 20%.
This fan isn't even twitching, just off all the time.
Kinda want it to spin now...
 


Hmm... this is a new model, factory new from corsair.
This is my 4th PSU from Crosair, I just want one of their PSU's to work correctly, honestly...

IDK what to do? is it suppossed to run quite hot and just never have its fan operate, or is my unit's fan faulty.
I haven't seen it budge, even on like system power-ups an stuff.
 
The fanless mode remains until the system requires over 500 Watts (523 Watts in KitGuru's review of the RM850) at which point the fan should start to spin.

Your system should be drawing less than 450 Watt with both the CPU at full load and the GPU running Furmark.

Maybe add a second Radeon R9 290 in CrossFire and the PSU fan should definitely spin under full load.
 


I'm thinking about it with R9 290's being under $230 on black friday this weekend

I want the PSU to stay cooler though, since it makes the rest of my PC hotter. It just refuses to cool itself. It's just ridiculous.
It feels hot, and hot air is floating out of the top and back, but the fan still isn't budging
 


Hmm, yeah it says in that link that the PSU doesn't spin up when turned on or off, but this heat still worries me. It is making my GPU hotter, and I have no way to tell the PSU to cool itself down?
 


Too bad the C Link feature doesn't allow the setting of fan speed profile. But then again you can't expect much from an analog controlled PSU.