wow this CX750M is loud...

[Jay Deah]

So i was getting frustrated about the fan noise on my PC and i just went to turn the fans down (240rad+360rad+2 case fans)

 

turns out the fans on the radiatoirs are dead quiet, the noise is coming from the PSU!

 

now i was expecting a near silence. were my expections wrong? the PSU sounds about as loud as the GTX1080ti STRIX air cooler was!

[seon123]

Why did you pair an entry level PSU with a 1080 Ti? At a gaming load, a 1080 Ti system should pull about 400W, which is about 1100RPM at 40°C intake. Corsair's quiet series would be the RMx. Some other quiet PSUs are the Whisper M and Straight Power 11.

https://www.cybenetics.com/index.php?option=database&manfID=28&volts=1

[jonnyGURU]

"Wow!  I spent a lot of money on my graphics card!  Now I have no money left over for my PSU!  Oh well!"

 

The CX-M is NOT sold as a quiet PSU.  That said, it shouldn't be "hella loud".  Is the noise a grinding or rubbing like a defective fan or is it just spinning full speed ahead?

[iRileyx]

Being the owner of a CX750m i'd guess its coil whine, mine makes a fairly noticeable noise.

[Jay Deah]

its just spinning at what i assume is full speed. no grinding, whining etc.

 

as for the choice of power supply, i messed up and bought this as my AX1200i didnt turn up, genuinely didnt realise it wasnt a decent spec unit as the packaging looked funky and it was the only semi-modular PSU on the shelf at the local shop. Will swap for an RM750i at some point soon

[Jay Deah]

as i go from idle to full(ish) load firing up CPU+GPU mining via nicehash you can see the temps+fan speeds are all quite reasonable but that damn PSU is drowning out all the other 7 fans, and it was at idle too, didnt increase when i started mining!

[Jay Deah]

one thing that worried me, if the CX750M is this loud, will the RM750i be just as loud, or should i be looking for 1000w+ units to keep the fan off?

[seon123]

7 minutes ago, Jay Deah said:

one thing that worried me, if the CX750M is this loud, will the RM750i be just as loud, or should i be looking for 1000w+ units to keep the fan off?

Look at the link I provided somewhere above. The noise level depends on the PSU in question, not the wattage. The RM550x is a lot quieter than the CX750M at 400W, which is roughly where you'd be sitting at with a 1080 Ti system. There are also other quiet options.

[jonnyGURU]

19 hours ago, Jay Deah said:

one thing that worried me, if the CX750M is this loud, will the RM750i be just as loud, or should i be looking for 1000w+ units to keep the fan off?

Some PSUs are quiet.  Some are loud.   You don't quite get that, eh?  ;-)

 

If your CX750M is really spinning at full speed, then there's something wrong with the fan controller.  While it doesn't have a ZeroRPM mode or an MCU controlling the fan curve like the RM750i does, it should slowly ramp up with the heat of the PSU.

 

Reference:

 

Corsair CX750M: https://www.cybenetics.com/a/Bkm/

 

RM750i: https://www.cybenetics.com/a/gVI/

 

 

 

 

[Jay Deah]

ok, so... i think i've worked out whats going on here and feel pretty dumb.

 

the case is an R6 on short legs but its sitting on the floor under my desk on new plush carpet. the feet sink into this pretty far and theres only a small air gap under the case for air to get drawn into. i think its genuinely overheating and hence running the fan hard. I propped it up on a book and now in the same conditions everything in the system stays nice and quiet!

 

So, just need to decide, do i put a plinth under the case, or do i rotate the PSU and have it draw air in from the chassis.

 

moving the case onto the desk isnt really an option, its a tiny desk 65cmx100cm with a 27" monitor taking all the space up./

[Mattias Edeslatt]

Buy a nice piece of wood and place under the case, or something like this 

 

or