Pecision 3620 CPU Fan Tweaking?

@Chino de Oro​ Thanks for the response! Earlier I thought the Fan Control setting just disabled the default fan setting and ran them at full speed, no matter what, but nope! Since you mentioned it, I went back and checked and yeah, it basically gives up fan control so I can now Tweak them in Speedfan, which is great. Thanks for mentioning that!

It's very strange but this is the first time I've heard it rev at full 2400 RPM, even though it previously was going pretty high in temps. For future reference, in Speedfan's Fan Control Fan 1 seems to be the CPU, and Fan 2 is the rear/exhaust fan.

It's the 3630's and 3640's and like chassis that aren't good with airflow.

Good move adding fans.  Since they don't have a way of mounting a front fan, I super-glued one.

I also like Chino's suggestion of going with a larger heatsink.

@bradthetechnut​ Yep! I also went the superglue route. I added a 92mm fan to the inside, behind the front panel and it's definitely improved the air flow. Not the best, but definitely much better. Not sure about the big heatsink though. I've seen it from searching older 3620 threads and it's probably not needed for a non-k 6700? I'm probably obsessing over the thermal numbers more than needed because while I get spikes in the high 60s/low 70s, the average is usually mid 50s.

Normally, 100°C is listed as a max temp for Intel CPU's.  However, for the i7-6700, a T-Case temp of 71°C is listed.  If you're concerned about temp spikes, the larger CPU cooler may be the way to go if your CPU is regularly under intense loads.

You said you mounted a 92mm behind the front panel.  Does that mean there's room to mount it between the panel and the chassis?  Mine is inside the chassis.

@bradthetechnut​ No it's like yours, inside that chasis. But yeah I think I've figured it out with this cooling thing. So, the fan apps are no-go. The only app that can detect them is HWINFO64, and even with Fan Control Override checked in the Bios, it still doesn't allow tweaking to the fan speeds. HWINFO will try to apply the speeds but it's overridden by the firmware (you can hear the fans revving up & down as it's fighting with it), so I'm just going to get a fan controller, probably pci.

The fans at full speed are quite a bit louder (I normally use headphones on my PC so I don't really hear it), but they're definitely going a great job of cooling as I was only getting max mid 50s (average 40s) after hours of gaming. But I'm assuming having them run at full speed for so long will definitely add wear so I will be getting a controller, and just power the fans directly from the PSU. It's so strange Dell just never lets their fans run at max...

Hey folks,

I have a resale Precision 3620 with an i7-6700 and stock fan (not the big heatsink). I've added extra fans to improve airflow, but the CPU still hits 60-70°C under heavy load. I want to manually control the CPU fan speeds because it doesn't seem to spin fast enough, suggesting an upper RPM limit.

Changing the CPU fan could cause boot errors, so I'm cautious about that. I'm looking for a way to override the CPU fan controls to enhance cooling without triggering these errors.

Any suggestions on how to achieve better fan control or alternative cooling methods would be greatly appreciated!

Thanks!

@skap97​ 

There's been many posts with some of Dell's other models about the fans running at max and being too noisy.  There's also a YT video of an old Dell PC, plugged in and running a game, being set on fire trying to kill it.  Guess what.  The fans ran on max while there was fire before the thing finally died.  The fire kept going out since PC's aren't made to burn.

The 2 extra fans I added to my 3620 run on max and are fairly quiet.  Like you, I don't hear anything else with the headphones on anyway.

@Hanira​ 

There is fan control override in BIOS, but the only option is to have them (Dell fans) run on max, which is quite noisy.  I think the easiest bet is the large heatsink with fan.  Be sure the airflow goes the right way flowing toward the back.  Should be an arrow engraved or stickered on it anyway.  Precision 3620 large heatsink on eBay

You can use software like SpeedFan or BIOS settings to manually control CPU fan speeds. Upgrading to a more efficient CPU cooler might help, though Dell systems can be picky with third-party fans. Ensure your BIOS is updated, as newer versions may offer better fan control options.

The heatsink I suggested is either Dell or specifically for Dell's, not 3rd party.