Sanity check - Corsair RMx under small load in a warm place

[pro lamer]

Hi!

I was worried whether I can buy this power supply unit since I want to store my future rig in a DIY open-case on a shelf near the ceiling. The RMx (850W) is advertised to run fanless under small load. Initially (until I buy a stronger CPU/second CPU EDIT: if I do it ever at all. If I do I'll do it maybe in 3 years) or after the drives finish they spin-up, my load will be low. I was worried of overheating - a warm place and the PSU fan off...

(EDIT: warm place = up to 33C/92F in hot summer days)

I found this thread (and this one) - the fan starts even under small load in case of overheating so my thread is a candidate to the SOLVED prefix...

Have I missed any important issue?

 

[MrToddsFriends]

The RMx (850W) is advertised to run fanless under small load. Initially (until I buy a stronger CPU/second CPU EDIT: if I do it ever at all) or after the drives finish they spin-up, my load will be low. I was worried of overheating - a warm place and the PSU fan off...

According to the Corsair RMx manual (fan noise curves) fan noise and thus fan RPM depends on power output and not temperature. If in doubt have a look for example at the Seasonic Focus Plus Gold / Platinum series, where the fanless mode can be switched off.

I'm using a Focus Plus Platinum 650W with the fanless mode switched off, where it is still nearly silent, PSU noise level considerably lower than the one caused by a couple of WD Red HDDs.

 

[pro lamer]

FWIW: I eventually ended up buying Corsair RM850i and Corsair link software can be used to set a fan profile, for example "max" or even a custom curve:

Anyway I don't know what way it works yet - for example if the setup is stored in some PSU memory or I need to have the corsair link running all the time/every boot-up and if it works with the open source version of corsair link.

I guess I can learn the answers by the means of STFW or in forums ;) or by trying out :)

 

[pro lamer]

Edit: I've just come across this thread:
http://forum.corsair.com/v3/showthread.php?t=185739

According to the Corsair RMx manual (fan noise curves) fan noise and thus fan RPM depends on power output and not temperature

Both the RMi and RMx series manual state both temperature and power output level are considered:

Zero RPM mode allows the fan to remain off during low to medium
loads. This technology uses various temperatures from inside the
PSU and the power output level to determine when active cooling
is needed for the PSU

Edit: but the thread I've just found states the temperature trigger works only for RMi

Anyway I tried out my RM850i under a very low load (50W) and:

• the fan started when the Corsair link readout reached 55.5 Celsius (The ambient temperature was between 48 and 50 centigrade)
• Edit: the fan initially ramped up to 2900 rpm for a moment
• Then the fan speed went down to 570 rpm
• After a while the Corsair link readout went down to the ambient temperature (48~50C)
• Then I let the ambient temperature go down
• The PSU temperature was going down accordingly
• The fan kept spinning until the Corsair link read 43.5 centigrade (ambient was almost the same)
• Edit: then the PSU temperature raised because of the fan stopped but it didn't go as high as previously because the ambient temperature had already gone down a bit. Hence the fan didn't start again. Then I finished the test

Only thing I'm not sure is if the Corsair link reads the thermistor responsible for starting the fan or some other thermistor. For example additional hidden thermistor designed to measure ambient temperature for internal purpose... Edit: Anyway the thread I mentioned above confirms the PSU has a few thermistors

if the setup is stored in some PSU memory or I need to have the corsair link running all the time/every boot-up

I made additional test: I set up percentage mode (40%) and the fan kept spinning when I disconnected the USB cable. Then I powered down and disconnected the mains. After connecting the mains again (without connecting USB cable) and starting the system the fan started spinning. So the setup survived somehow.

Then I got new doubts:

• If the setup is non volatile or there is some battery?
• Is the whole detailed setup stored or only roughly (for example only if the fan is spinning) ?

But well I think I don't need answers to these two questions ;)

Sent from my phone