XPS 8940, Better 3rd party cooler

@LikeHerdingCats - good for you ! never too late. Well, too late for me, I'm retired and loving it ! I was over 40 a good 20 years ago !

You got it (25mm) ! Good luck, keep us posted !

@bertro514 - haha !

Have you ever watched any of Greg Salazar's PC cleaning videos ?

https://youtu.be/gAICgrSw2x4

@SteveK318 yep, when the filter was brand new and clean, lol. 

@SteveK318 never knew of him. Thank you! Good to know! I must say reversing the airflow makes it so easy to clean the top filter. Just one swipe and all the dust goes away. I'm scared of what I'm going to find on the lower filter when I make time to open the case, though... 

@bertro514 - you're welcome !  

glad the reversal is working... I may just try it someday if I get bored !!

@c_higg Sorry for the very late response, but I installed the Noctua Noctua NH-U9S, and works great. Although if you don't keep at least one of the stock fans connected, sometimes at boot up when it does a motherboard fan check, it gives an error. I fixed this error by attaching the rear fan to the front by using zip ties and by connecting it to the rear fan connector by using a y splitter. I put the Noctua NF-A9 as the rear fan instead. One recommendation is to not put a second fan on the CPU cooler as I have only seen a 1-3 degree difference when gaming/underload. Hope this Helps!

Just got a dell xps 8940 with the i5 11600k it came with the new dell tower cooler but still seemed to get hot. I installed the noctua 90mm fan in the back (blowing out), a noctua 120mm fan in the front where the hard drive cage was (using 3D printed bracket), and added a noctua D9L cooler with 90mm fan. Install was easy and no errors. I am still getting temps though in the 70s to low 80s. Why do other people have success but it seems to not have helped me. 

I should elaborate and say the temps during cinebench and gaming go to around 78-81 according to nzxt cam. Before they were a little higher in the low 80s but there was not much of an improvement. Some people mentioned seeing temps in low 70s while under load. I have all the air going from front to back. I also followed the guidance of a “grain of rice” size amount of paste. 

@spartyon11 - I'll just throw in my 2 cents here... I have a G5 non K cpu which came with the dinky stock cooler... When I ran the benchmarks, I was hitting 100c  ... My first update , I replaced the cooler with the NH-U9S (1 fan) , replaced the Dell rear exhaust fan with a NF-A9 fan. If you want to wallow your way through these photos, you'll see that my benchmark temps were like 74-77c.  I've since added the 2nd fan on the cooler, and a 120mm up front, and and 80 below my GPU .. I'm satisfied with temps, although off hand, I'm not sure what the numbers are for this configuration.  I'm guessing with an i5 11600k and the bigger Dell cooler, you weren't hitting 100c ... One thing I did notice on the Noctua site, and I'm not sure how much difference it would make, but the NH-9US has a performance rating (NSPR) of 93, and the NH-D9L is 88.

Hi @spartyon11 ,

I  have  done more or less the same upgrades as you but I have the  i7-10700 (non-k) and I started with the tiny “pancake” cooler which had me maxing out at 100 degrees within a few minutes.  Afterwards I stay within 75 max at full load. You asked what you thought the difference could be comparing your results with others so just a few observations from my experience. 

Not sure if these observations help answer your question but thought I' d share anyway:

Cooler

I went for the NH-U9S not the NH-D9L. Seems they are both excellent coolers but I read lots of reviews including this one which is detailed 11 page review directly comparing NH-U9S vs NH-D9L and concludes by saying results are very close but recommends the NH-U9S:

https://www.guru3d.com/articles-pages/noctua-nh-d9l-and-nh-u9s-cpu-cooler-review,1.html

Other reason I went for the NH-U9S is it has 5 heat pipes (vs 4) and also it is slightly bigger at 12.5cm high (vs 10.5cm).  Also as mentioned by @SteveK318  the NH-9US has an NSPR performance rating of 93 (vs 88). Not suggesting  of course that you switch now but just tossing this in for information.

Fans

In addition to the upgrades you did I also added a second 92mm fan (Noctua NF-A9 PWM) to the cooler itself so there is push-pull back-to-front flow through the cooler. In my tests this reduced CPU temps by a further 3 degrees….so not huge but could be worth you doing the same if you haven’t already.

Thermal Paste

You mentioned using the “grain of rice” amount. In my research I came cross that description a lot but to me an actual grain of rice is tiny !! (I know you can get different types of rice but still....).  I actually squeezed on a round pea sized blob about 6mm diameter so it is just possible if you took the “grain of rice” literally you may not have used enough and could be worth removing the cooler, cleaning and re-applying with a tad more paste.

No. it doesn't. its still loud and hot in thst case. I really not caring for the motherboard either. the bios does not allow you to change settings. why did they go from a modifiable 8930 to this? money and lots of inspiron cases around. Im thining of gutting the system. Taking the cpu, the ram, the gpu, the wifie 6, and bT 5, and drives (2) and leaving just the motherboard, stock fans, and dvd writer/player. Put it all in a better mobo, asus Tuf or Prime, b560 or h570 respectively. I have a mid tower sitting around, with bluray, and 700 psu. If one adds up the cooler price, the fans, the screws, etc. It comes $105. So, the two mobo's listed above cost 129 and 139. (n e  w   e g  g). I'll have three years with any of those mobos. So, for $50 more.. a better rig. my two cents.

@spartyon11  I agree with @Gambit_man : there might not be enough paste. I recommend removing the cooler and taking a look at how the paste was distributed over the CPU. Did it spread evenly over the entire lid? I recommend a pea-size amount and make sure to tighten the cooler screws enough (not forcing them, but do tighten until you get resistance). Also, double-check that the fans are actually spinning up properly under load. Might want to double-check the connectors if not.

If your high 70s/low 80s are in all-core benchmarks like Prime95, Cinebench, Blender, etc, then it's actually not that bad. However, gaming should be much lower (60s), since games don't use that many cores. 

If you reseat the cooler and connectors and  and still not getting decent temps, you could also look into undervolting the CPU a bit. I've undervolted my 10900 by -125mV and that took about 5 extra degrees of the temps, as well as reduce wattage without reducing performance. Undervolting is not as straight-forward as it used to be, but can be done in less than an hour.

@bertro514 @Gambit_man 

Thanks for the advice. I was typing those from my phone and I didnt have a computer at the time to properly write anything (I hate typing on my phone but wanted to get something posted). When I was looking I did see the "pea size" and "grain of rice" advice for the paste. I first installed the cooler and used about a grain of rice (smaller than I should have). I removed the cooler a minute later because I needed some working space in the case for fan installs. When I took the cooler off, it did distribute evenly over the entire face of the CPU. it was as good of coverage as the stock paste was when I removed the stock cooler. When I reinstalled the cooler (new paste) I used a larger amount than a grain of rice. I would say it was a "fat grain". it was definitely more than i used the first time. With this in mind, I am fairly confident that I have enough paste.

When running cinebench, it hovers around the high 70s and goes into the low 80s a few times. I think the max was around 82 or so. It wasn't that much better than it was stock with one small fan and the stock cooler (maybe 2 degrees). I pretty much only play Warzone and the temps stay in the 70s. I am sure this is good and sufficient for what I am doing. I just thought for over $100 I would see at least a bigger drop in temperatures. Maybe it is because most people do the swap from a wimpy pancake cooler and I upgraded from the "better" dell double tower cooler. 

I did do a lot of research on the 9s vs 9l and saw that some reviewers said the 9L was better and some said the 9S was better. All the reviews that I saw essentially said the same thing, there was not much (if any) difference between the two coolers. Maybe I should have went with the 9s but i am not sure it would change much if anything at this point. 

@SteveK318 What temps and performance do you get out of this?

I'm looking to make the same mods to the new XPS 8940 with 11700K and 3070 gpu, so all advice and performance info is deeply appreciated.