Sign in with
Sign up | Sign in
Your question

Overheating Mobo & CPU - Airflow Advice

Last response: in Systems
Share
September 3, 2010 8:01:49 AM

Hi Everyone-

I built my first system a couple months ago with the LANbox Lite case, and various high quality budget components (listed in my signature). Since building the system I have constantly struggled to keep it cool, esp through the summer months without air-conditioning. I am using everest to monitor temps and have tried a number of ways to cool it down already:

  • Initial overheating using stock hsf - hit up to 70 degrees for the cpu, mobo at about 65
  • improved this by using arctic silver 5, replacing IDE cable with a rounded one, moving HDDs from cage to 3.5 bay and 5.24 bay (with adapter)
  • At this point the system was less likely to heat at night, but would over heat on hotter days when playing games. Temp peaked at 67 on average nights
  • I tried flipping the PSU over to suck air out of case instead of having it suck in fresh air from the top and push it through the back (not inside the case). Although this seemed counter intuitive as it worked against the airflow- but somehow with the stock hsf it actually improved the temp by about 3-4 degrees! I think this has to do with the low profile of the OEM heatsink
  • For about a month performance was pretty good- 45 . Then one day it started overheating again for no apparent reason (no changes in hardware!)
  • Bought and installed BlueOrb 2 with Arctic Silver 5 with PSU in original position (not facing inside case). Mobo and CPU overheated very rapidly on a medium load, and mobo overheated before cpu
  • Cracked open the PSU and reversed fan airflow as suggested by few previous posters about LANbox Lite's problematic positioning of the PSU directly above the CPU Cooler. Unfortunately none of these past posts explained what is to be done with the two rear and one frontal fan (this was asked but never answered). Processor temps drop on idle by 4 degrees to 43 but overheating is frequent. Mobo gets alarmingly hot (72 degrees) even before the processor does on a full load.

    So this is where i'm at- I am attaching a diagram that shows my current airflow. I know its not well engineered airflow wise, i'm just not sure how to fix it. One thing to note with the current configuration that I couldnt indicate in the diagram is that somehow hot air blows off the motherboard through the left side window vent, while very little blows through the right side window vent. this also does not seem to make sense as the right side vent is incredibly close to the CPU Cooler but the left side is about 8 inches away from it. Also this BlueOrb II brags about how it cools adjacent components- it does worse job than the stock heatsink in my case!!

    For now i'm "underclocking" a processor designed for overclocking! i am using advanced power management in windows 7 to run at 70-90% clock depending on ambient temps. fortunately this lovely (albeit very hot) processor is adequate even at 70% for all my heavy needs :) 



    Thanks for helping!!

    -Mizz P

    EDIT: It seems that theres a cut off on the signature line- here is my list of components:

    Case: Thermaltake LANBOX Lite VF6000BWS
    Motherboard: GIGABYTE GA-MA785GM-US2H AM3/AM2+/AM2 AMD 785G HDMI mATX
    CPU: AMD Phenom II X4 940 Black Edition Deneb 3.0GHz Socket AM2+ 125W Quad-Core Processor HDZ940XCGIBOX
    GPU: Onboard (ATI Radeon HD 4200)
    CPU Cooler: Thermaltake CL-P0257 Blue orb II CPU Cooler
    PSU: OCZ ModXStream Pro OCZ500MXSP 500W ATX12V V2.2 / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply
    RAM: G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ
    a b à CPUs
    September 3, 2010 8:51:44 AM

    I would ALWAYS have the PSU blowing air out of the case. PSU's get super hot.. the last thing you want to be doing is pumping your case full of hot air from your power supply. Can you not add a fan to the top (or bottom) of the case?
    a c 122 B Homebuilt system
    a c 172 à CPUs
    September 3, 2010 9:20:33 AM

    Restore the direction of the PSU fan and try reversing the CPU fan so it sucks air up from the CPU. That way you have all the fans working together.
    Related resources
    a b B Homebuilt system
    a c 117 à CPUs
    September 3, 2010 11:16:19 AM

    ^+1 exactly!
    September 3, 2010 5:50:46 PM

    acer0169 said:
    I would ALWAYS have the PSU blowing air out of the case. PSU's get super hot.. the last thing you want to be doing is pumping your case full of hot air from your power supply. Can you not add a fan to the top (or bottom) of the case?


    It isnt possible in this particular case without doing heavy casemods to cut holes in the top. also this area (between Hard Disks and PSU is where all the excess length of the cable is being stored and where the IDE/molex plugs jut out of the sockets on the DVD drive and HDD
    September 3, 2010 5:53:47 PM

    jsc said:
    Restore the direction of the PSU fan and try reversing the CPU fan so it sucks air up from the CPU. That way you have all the fans working together.


    thank you for your suggestion- i had this in mind as well initially, however it was suggested multiple times that this is a bad idea to reverse airflow on CPU Cooler by several on this forum. i guess there were some who argue in favor of a pull fan on the cpu cooler if the correct airflow engineering is done. Even so, it does not seem possible to reverse airflow on the Blue Orb II cpu cooler as it doesnt use a standard type of fan and is anchored by the center, not by the sides, which means that i cant flip it and screw it in. Any ideas how to do this? I have searched for it and not found anything specific to this CPU Cooler.
    !