Crystal 280x Running Too Hot

Hey everyone,

 

I have a Crystal 280x mATX case with H115i 280mm AIO mounted on top as exhaust and two front intake LL 120s.

 

My problem is my 9900KF is running low 40s °C on idle and can hit mid 80s or even 90s on medium-high load gaming. Prime95 with AVX makes temps jump above 100 °C.

 

Do you have any suggestions on how I can drop my temps? I am thinking on getting two LL 120s for bottom intake, would that help or is my problem more of a botched installation/wrong system setup?

Prime95 just produces heat for the sake of it tbh, there is really nothing substantial to gain from using that. what you can do to improve, is flip the AIO fans to intake and use proper static pressure fans on the radiator. raise the top glass panel by a few mm with some spacers or remove it completely for better airflow. that will help a bunch.

front fans can stay intake, flip bottom to exhaust. you want cold air going through your rad, not preheated air from your gpu.

should account for a few degrees speaking from my own personal experience (I've put a full custom loop in that little box with a 9900k)

You need to take a look at the coolant temperature change (H115i Temp) when gaming. That is the amount of heat the cooler can reduce. If you start off at 30C and it increases to 36C, then 6C is the most you can possibly reduce CPU temps with any fan speed. In reality you can't ever get back to a zero state, but that is the general idea. The normal rise is pretty easy to calculate on straight wattage vs radiator size, so an abnormal change during gaming might indicate case heat problems.

 

However, you also should figure out what your Vcore voltage is getting up to. Most users with immediate "on load" temperature problems are on the auto setting and it is not meant for synthetic stress testing. 5 minutes of Prime may be too much for the CPU, but it won't heat the case up.

40° on idle is weird, unless it's like 30° in your room.

Basically you have low static pressure fans in a very restrictive case so you may have to fine tune the overclock to avoid generating too much heat, and brute force some air in if it's not enough, running higher RPM, or adding / replacing fans.

Thank you so much for your answers. I'll try running AIO fans on extreme and manually lowering Vcore voltage today.

 

If that doesn't help, then I'll think about reversing the AIO fans and maybe add extra fans.

You can use the coolant temp change as a general indicator of case heat. Most users would see a +5-6C H115i Temp increase for a 9900K while gaming for CPU heat alone. Of course, if you have an open fan style GPU that will add heat to the case. A more typical mixed load coolant rise would be 6-10C. If you are beyond +10C rise while gaming, that may suggest case airflow problems. However, obviously the 280X is smaller case so practical options and improvements may be limited.

Just tested playing some Battlefield V. Idle coolant temp was around 31 degrees. But it jumped to 46 degrees while in game. CPU package temp was mid 30s and apparently it hit as high as 86 while in game. The whole time fans were in extreme mode.

 

Something's not right with my setup.

What's your Vcore? How is your cooling setup? (for the whole case - fan orientation etc.)

hard to tell with just "my temps are high" - we would really need some more input here

Yeah sorry for not providing extra info. Like I said in my original post I have Crystal 280x with two 120s in the front running intake and AIO mounted on top as exhaust. This is pretty much it.

 

It was just my OC was on auto and whatever Vcore Gigabyte seemed fit was running. Been tinkering with it for the past couple of hours now, set my Vcore to 1.31V and multiplier to 48. Running a prime test as I'm writing this (No AVX) and 4.8 GHz under 100% CPU load and my max temp is currently 75 degrees.

 

I just may have found the sweet spot.

Auto voltage + altered multiplier will almost always pack on extra juice. That is a quick and relatively easy fix.

 

The +15C on the coolant rise tells us the case is heating up. There might be 5C to pull back that benefits everything in the case and coolant temp is baseline cpu temp. However, working with smaller cases is harder and very specific to that model.

 

Maybe we can get some 280X owners in here with first hand experience.

as mentioned, your best bet would be flipping you aio to intake as well and get 2 additional fans for bottom exhaust. it will be better if you remove the top panel as well.

 

edit: you might as well put the radiator in the front with intake fans, bottom intake, top exhaust. that might be the optimal setup for this case with an aio

Edited June 27, 2020 by Infin1tum