XPS 8930, cooling plan advice

Question

I have a XPS8930 with the i7 9700 and GTX 1660Ti I bought a few months ago. I was aware of the temp issue, but I am not that big of a gamer so I thought it would not be a big issue for my purposes. Because I've been staying home all day now, I started playing some higher-end games on it (COD) and temps are usually in the high 70s and 80s on modest graphic settings. It is very loud too. Idle temps are from 30s-40s. Other lower-end games run anywhere between 50s-70s on max settings.

I first tried using QuickCPU to lower the max CPU performance anywhere between 4.30 - 4.00 GHz, down from 4.70, which actually helped. Temps were mostly in the 70s, but after a while of playing games it skyrocketed to the 90s and I decided it was time to implement some of the other solutions this community forum has found to work.

I am planning to replace the stock cooler with a Arctic Freeze 11 LP and upgrading airflow by adding two Noctua S12A FLX 3 pin fans at the top exhaust and lower intake areas. I've read that this has been successful for some. Does this sound a like a good plan of attack to hopefully lower the CPU temps and noise? Would you suggest anything else? Btw, if it wasn't already evident, I know nothing about computer modding so please bear with me.

GKDesigns · Answer

@xpsistoohot

Do the two 120mm case fans first. You may not need to change the stock CPU cooler.

https://www.dell.com/community/XPS-Desktops/XPS-8930-how-is-the-cooling-in-the-i9-9900/m-p/7508730/highlight/true#M46666

GK

xpsistoohot · Answer

Alright, I will try the two fans (two exhaust and lower intake) first as advised. Just a little confused about the difference between Noctua PWM (as used by GKDesigns) and FLX (as used by HanoverB) and if there was one preferred over another.

xpsistoohot · Answer

Ahh okay got it. I will go with the FLX then. Also, if I'm understanding the instructions from the other posts correctly, I would require a different top exhaust metal mounting plate, since the one I have is for the 92mm OEM fan, in order to mount the Noctua 120mm fan up there. As for the front lower exhaust, in order to mount the other Noctua 120mm to that, I would also require the plastic bracket from an Aurora R5, etc, which snaps into the metal chassis easily, even though GKDesigns went ahead and drilled holes into his chassis instead. Is this correct?

xpsistoohot · Answer

Thanks! I've gone ahead and ordered the fans and brackets, hopefully they'll be here by the end of next week. Also, I noticed you've also upgraded your PSU as well. Do you think that is something that is necessary?

GKDesigns · Answer

@xpsistoohot

Alright, I will try the two fans (two exhaust and lower intake) first as advised. Just a little confused about the difference between Noctua PWM (as used by GKDesigns) and FLX (as used by HanoverB) and if there was one preferred over another.

I believe this is explained in the other linked posts. Plus Google Search and the Noctua website provide plenty of additional information.

I used two PWM fans and modified one of the included y-harnesses to run them at full 1200 RPM. That was overkill and noisier than stock cooling. So, I used the remaining unmodified y-harness to run them at the variable speed determined by the motherboard, just like the 92mm top case fan they replaced. They are much quieter and only rev up when the CPU is stressed, which is not very often and generally never if compared to the stock 92mm fan.

If you get two NF-S12A-PWM fans, you can run them in all ways: full speed (1200 RPM) with a y-harness modified to 3-conductors; reduced speed (900 RPM) with a low noise adapter; or variable speed PWM (300-1200 RPM) with an unmodified y-harness.

You should have ordered the PWM fans. The Noctua fans are quiet, but you will hear two of them running at 1200 RPM (it's the airflow through the case grill that makes the most noise, not the fan motors). Even the stock 92mm fan doesn't run at full speed all of the time.

GK

xpsistoohot · Answer

Hmm... I was going off of what Dell630i said about how they were usually always quiet, but I guess you had a different experience. If the fans are louder than the stock cooling, that will be a big issue for me. I can still cancel the order for the fans, so I'll give it some more thought.

xpsistoohot · Answer

Understood and I appreciate all the help you guys have been offering me, I'd be left in the dark without this community.

GKDesigns · Answer

@Anonymous  I could be wrong about this, but I believe if you run two fans off a Y-splitter, only one fan can be modulated. See if your Y-splitter cable looks something like this Yes, the Noctua PWM Y-harness looks similar to your pic: conductor/pin1 (0 vdc) routes to both fans;conductor/pin2 (12 vdc) routes to both fans;conductor/pin3 (RPM signal) routes from only one fan (master fan speed feedback);conductor/pin4 (PWM signal) routes to both fans for variable speed control. So, only one fan provides the RPM speed feedback signal, but both fans receive the PWM variable speed control signal.  I suggest connecting the Y-harness so that the top case exhaust fan is the master fan (connected to all four conductors). See my post again for the actual wiring diagram:https://www.dell.com/community/XPS-Desktops/XPS-8930-how-is-the-cooling-in-the-i9-9900/m-p/7508730/highlight/true#M46666 You are correct in that both fans are not directly speed modulated... one is slaved to the speed feedback control of the other.  But given all things considered being equal... it's as good as being directly speed-controlled.  My two fans rev up and down in unison like a fine-tuned machine... mostly they idle at some low RPM. If you cut conductor4 (PWM signal) at the motherboard connector, you'll get a 3-pin non-PWM circuit... both fans will run at full speed.  The BIOS will see the full RPM signal and generate a PWM signal to slow the fans down, but it doesn't connect anywhere. GK

xpsistoohot · Answer

@GKDesigns

I decided to go with the PWM fans, it made more sense to me to have the fans run at adjusted speeds as need be. It also gave me some more options down the road to modify a y-harness to run them both at full as you've tried. Hoping that I will see some CPU cooling effect and decrease in max temps under heavy loads without having to replace the stock CPU cooler. Thanks.

xpsistoohot · Answer

I received the top exhaust bracket today and was able to install one noctua fan there today. The size difference is massive. However, the cpu was still very hot, I feel like it was even hotter than when I was using the stock top exhaust fan. Temps while gaming were in the mid to high 90s as opposed to high 80s with the stock fan. Any ideas as to why this is? I attached a pic of it installed, it seemed like an easy fit and plug, but perhaps I installed it incorrectly?

xpsistoohot · Answer

Thanks for the explanation. I'm receiving the lower bracket part Monday, so I'll get it installed at that time and let you guys know how it fares.

GKDesigns · Answer

@xpsistoohot

Your top case fan looks good. It's probably running faster than it would with the lower front case fan installed. It does not have the best static pressure spec... ability to force air against a resistance (that would be a noisier fan)... so it will be fighting the case air pressure. When you get the lower front case fan installed directed inward, the case air pressure will increase and the top fan will exhaust air more easily. Then you will know how your system will cool and sound with the two new fans. Finish the job.

GK

xpsistoohot · Answer

I think you should be able to see it now. I’m not sure how to measure the fan speed, but it is pretty loud, so I can only assume its running near/at max 1200 rpm.

xpsistoohot · Answer

So I've gone ahead and installed the front lower fan with the correct plastic mounting bracket and plugged now both fans to the header using a Y-splitter and extension cable. It was noticeably quieter and initially very cool during games (surprisingly in the 60s), but my CPU temps eventually increased (although much better than with the stock fan) and stayed around low 80s. It then got loud. It did not really ever break 90 degrees. I'm not sure I'm willing to upgrade the CPU cooler at the moment. I did already have NZXT Cam running, but for some reason I am not able to see the Noctua speeds under the cooling tab.

GKDesigns · Answer

@xpsistoohot

Max temp for the i7-9700 is 100C. Ideally, you want to keep 15-20C below that. Low to mid 80s is not bad.

Don't forget to service the lower front fan grill as required to clean it off. If you don't, your system will remind you.

GK

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XPS 8930, cooling plan advice

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