Inspiron G5-5090, CPU cooler?

@MirkoLeo  and @DGArmond , thanks for the info--it does appear that there are hardware and software differences at play. My G5 does not give an error when checking fan speed (even though the Noctua fans run at 60% of the RPM of the OEM fans). In fact, in HWinfo, the (incorrect) OEM max RPM is still listed for the fans.

@MirkoLeo  yes, I can still control the Noctua fan via AWCC, and I have it connected directly to the fan CPU connector on the mobo. I do not, however, see the same behavior you're seeing with the fans ramping up to 100% on cold boot or restart, maybe because I don't have the OEM fan still connected. Of note, in AWCC, the fans will never get above 60% speed, since that is the Noctuas' max RPM.

Thanks @deskjockey98  for all the info!

To sort out the thing I think I'm going to try connecting ONLY the single noctua fan via the 4 pin connector, and see how it behaves. Eventually I can take a look in the BIOS to see the default fan setting, maybe they're set to high and only changes the behaviour once awcc completely loads after the boot. 

I'll have you updated in case anyone is interested!

@deskjockey98 Finally I managed to try and better understand everything.

- I tried to disconnect the OEM Dell fan from the noctua splitter and no error of any kind showed up, yessss. The AWCC showed a fan speed of 51% at 100% offset, in agreement with the noctua max rpm (2000) vs the oem dell fan (4200 rpm)

- I also solved the issue concerning the maxed out fan when rebooting/restarting. Basically I was using a personalized thermal profile, with the smooth line function. The problem is that, with my pc but maybe it's true also for others, any thermal profile different from QUIET, PERFORMANCE and BALANCED is loaded only AFTER awcc is opened after booting the pc. So, before any personalized thermal profile is run, the system uses the last default profile used (Q, P or B), and in my case the last profile used before selecting the personalized smooth curve was right the PERFORMANCE one. 

It's still strange to me that I need to open awcc before the thermal profile switch (I think it should be automatic), and also that everytime I close awcc the screen flashes black for an instant...

Hope this info can help someone!

Thanks, @MirkoLeo  and @DGArmond . It does appear that the different mobo and BIOS is playing a role in whether you get a POST error using just the Noctua fans, and it's also good to know how AWCC is handling fan curves. My guess is that AWCC's behavior applies to folks running OEM fans, too. Not exactly a good implementation, frankly.

@ke_rico can you share your XTU settings again? the original upload is no longer available, thanks!

Another unhappy customer whos got the G5 10700F, RTX 3070 here

Reading through the last 15 pages gave me a good idea as to what needs to be done.

I ended up getting:

https://www.amazon.ca/gp/product/B00TBHYYFK/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

https://www.amazon.ca/gp/product/B0795DP124/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

https://www.amazon.ca/gp/product/B009NQM7V2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

(with the stock fan going to the front panel)

Since this is the first time I'm ever doing such 'mod', I'd would appreciate if you guys could post some 

pics showing a closer look at the wiring, connections, ysplitter etc.

Thanks. 

@Vortex1337 

One important note about fan wire splitters, which I don't recall being mentioned recently, applies to Noctua's 4 pin splitter. One of the legs is 4 pin and the other is 3 pin. If the BIOS in your machine performs a hardware scan on boot up and you are using the Dell fan as a work around be sure to connect it to the 4 pin lead.

In my system (G5-5090, i9-9900 not K) I disassembled the Dell cooler to use just the fan and mounted it to the case front below the hard drive. The only thing you need to do is remove the power supply wire from the plastic cable guide. Leave the guide, the 80mm fan will fit against the perforated area using the cable guide  to support the fan. Use the perforations to secure the fan to the case. This fan is connected to the 4 pin side of the cooler splitter using an extension cable. The Noctua NH-U9S is connected to the 3 pin lead.

A Noctua A9 PWM fan replaces the rear Dell case fan. I mounted this Dell 80mm fan to the  NH-U9S cooler in a push / pull configuration.  The coolers Noctua A9 fan mounting system can be referenced to mount the 80mm fan. The  Dell fan is connect to the 4 pin lead and the A9 case fan to the 3 pin lead of the rear fan splitter.

The advantage of this configuration on my machine is a normal bootup at all times. One thing to know is the Dell fan speeds will increase as CPU load increases. Under very high loads they become audible but have never reached a speed which is annoying.

Note, thermal paste is furnished with the cooler, no need to by extra.

@Vortex1337 

Based upon most recent comments there appears to be no way of determining how a BIOS responds to a non stock fan.  A test of the BIOS by replacing a fan is probably the only way to determine.

Here is the progression I followed. Replaced the cooler and case fan with Noctua U9S and A9 respectively. On cold boot BIOS POST reported critical fan error, same error on a Restart. Added the Dell cooler fan to case front only. This corrected error in Restart but not cold boot. Added Dell case fan to cooler as previously mentioned result is everything back to normal.

I have a second A9 fan that I had used on the U9S in push/pull, the result was no real improvement in cooling. A few independent tests from on line reviewers confirmed this fact. Personally I think the cooling affect of using push/pull is limited in this computer case because the pull fan is too close to the rear case fan disturbing the air flow path.   The reason I attached the Dell 80mm fan, it was a the only easy viable location to mount it, but contributes nothing to overall cooling. The purpose of using it is getting back to a normal bootup while maintaining acceptable CPU thermals.

Hope this helps...

@DGArmond 

Thanks for the reply.

Correct me if I'm wrong, if I choose to go with 2 Noctua A9 PWM (one in the front, one in the back), it might trigger an error? 

@DvorakKR 

Motherboard and case design do not provide space for 120mm cooler. G5s are limited to 92mm hardware.

Will the Dell G5 5090 support the Noctua NH-U12S?

@DvorakKR 

Yes, the Noctua NH-L9x65 should fit, it is a 92mm cooler. Depending on your cooling needs the NH-L9x65 is a lower cost option. However, it does not have the cooling capacity of the NH-U9S or similar full size coolers. If your machine is configured for high performance gaming and its primary use then a lower capacity cooler may not be the best choice.

If you need more information consider checking Noctua's website for comparison technical data. NH-L9x65 (noctua.at)

Hope this helps...