New heatsink is 3-5C hotter than stock heatsink


I installed a Rosewill RCX-Z300 heatsink in my Dell Inspiron 530 (Q6600) today and found that it runs 3-5C hotter than my stock heatsink. My stock heatsink is all aluminum and has a smaller fan compared to the Rosewill. Also, the Rosewill has a copper bottom (top is aluminum). Any thoughts on why this is happening?

When I removed the stock heatsink, I used Isopropyl alcohol (70%) and Q-tips to clean my CPU. The Rosewill had a layer of gray thermal paste on it from the factory. I doubt I have a contamination or thermal paste application problem.

The nice people at Dell conveniently stickered the screw bracket to the backside of my motherboard so I can only use screw based heatsinks. The Rosewill uses the push-pin type connectors so I had to transfer the spring screws from my stock heatsink to the Rosewill; which went easy enough. I figure if I did a poor mounting job, I'd have cooked my CPU or had a much larger difference in temperature.

I'm using the current version of RealTemp running on Windows 7 32Bit.


Colorado Springs
7 answers Last reply
More about heatsink hotter stock heatsink
  1. The cooler you've bought is quite a low end cooler so the thermal paste it comes with might be of poor quality or might need time to set (paste like AC5 needs 200 hours of use before it's 100% set and gives best results). I'd look at getting some MX-2 thermal compound and try that. It's cheap, but gives very good results. 8C cooler than stock paste when I replaced a cooler in my second machine.

    If you did a poor mounting job it doesn't always have a big difference in temps. I've cleaned my cooler before and mounted it again to find temps had gone up slightly. I took it off, cleaned the paste off and tried again and temps were better.

    Also it doesn't matter if your heatsink is a bit bigger if it's fan isn't moving the same amount of air. Typically, Dell have small heatsinks but loud fast fans that do the job well.
  2. Hello,

    I removed the Rosewell heatsink and re-installed my stock Dell heatsink. I re-ran RealTemp and my numbers are 3C cooler than before the upgrade. I used some silver thermal compound I picked up at BestBuy for $10. Looks like it was good stuff. So, the difference between the Rosewell and my stock heatsink is now 6-8C.

    I found a few posts from other Dell Inspiron 530 owners that have installed the Zalman CNPS9500 AT. From those other posts, people are seeing ~6C cooler numbers over their stock heatsink. On NewEgg those run $40. I'll have to decide if it's worth it. My box is running at 48C while idle now. The RealTemp example screenshots show a Q6600 running at 27C idle... Wish I knew how he got his chip so cool.
  3. If I were you I'd try to remove all the pre applied thermal paste from the aftermarket heat sink and then use something good. Arctic Silver 5 comes well recommended. then try remounting it. Make sure you screw it in tight.
  4. your Dell may be setting the fan speed too low for an aftermarket cooler

    also if there isnt enough pressure to the hsf then you will get the float effect and it will not work properly - use the correct fittings that came with the HSF - a hair drier to heat that rear bracked will loosen it so you can get it off

    you cannot cook an intel chip like that - you take the hsf off and it still wont damage the cpu it will shut the system off
  5. That rosewill cooler is actually made from leftover of Intel shelves. Those coolers from early C2D or C2Q processors. The fan is aftermarket of course, but you can modify the original intel fan by just getting rid of the external thermistor. The intel fan is made by delta, which also make those crazy 250CFM fans. Without that annoying thermistor, the fan is very good.
  6. So I did some research today and found that several people have been successful at installing the Zalman CNPS9500 AT. NewEgg carries them for ~$40. Here's a picture from Dell's support forum

    I'll post another update once I've gotten that installed : )
  7. I don't think $40 is all that much to pay for a half decent cooler. I mean I've got a £45 (GBP) cooler which is what like $60? I want to keep my CPU cool, so I pay the money. I'd never expect good results when only spending a fiver on a cooler. The Zalman is a very good cooler though - very popular for a reason. I used it in a recent build which can be seen here:
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