View Full Version : CPU temperatures with different setups and heatsinks

2nd April 2009, 15:08
Until a couple of years ago I always tended to use the stock heatsink/fan that came with a CPU. However I have recently been building systems with custom heatsinks, and the difference in both the noise level of the fans, and the drop in temperature, compared to stock units is quite significant.

A few years ago I was running 3 systems with Athlon XP 3000+ CPUs, and for anyone who has owned a system that used the Athlon XP chips will know, these like to run quite hot. Not quite up there with the worst of the Pentium 4's, but still quite bad. Also the thermal maximum was lower than the P4 with about 70 degrees C being the limit for the Athlon XP 3000+.

My main system at the time suffered quite badly from high temperatures. The CPU would often be idling in the high 40's and would shoot up to the high 50's, and sometimes into the 60's on a warm day when playing games. That always concerned me, and sometimes the system would reset itself without warning, which I'm sure was heat related.

Another of the Athlon XP systems, using an identical CPU and heatsink, but a different MSI motherboard ran about the same 46 Deg C while idling, but under load it only ever went up to about 50 Deg C max. Very odd that so much different was present between the two systems, and shows that a different case, fan arrangement and motherboard can make a big difference.

At the time the hotter running main system was in a case with 4 80mm front case fans, and 2 80mm rear fans, but it was still hot. I always thought the case was to blame. However when that hot system's PSU finally failed, and killed the motherboard with it, I obtained another identical motherboard from ebay, but installed in in a new Thermaltake Soprano case. These have a great fan setup with 120mm fans front and back, and a 90mm side fan. But with an identical motherboard as before the CPU still ran very hot and quite unstable. I even fitted a Cooler Master Jet 7+ CPU cooler to it, but the temps didn't change. It just made it louder!

I never did fix that overheating problem, and that motherboard and CPU are now in a box as spares. The cooler Athlon XP system is still however being used and I've actually just been reconfiguring it a bit to take over from my existing Althon XP 2000+ download server.

I thought I would try the same Cooler Master Jet 7+ in it. With a stock heatsink the system was idling at about 46 Deg C, which was fine for an Athlon XP. However I fitted the Cooler Master Jet 7+ this morning, with some Arctic Silver thermal compound and have been running the system for the last hour with the Everest Stress test. The system is now idling at 37 Deg C, nearly a whole 10 degrees lower! And in the stress test under full 100% CPU and ram load it is running at a maximum of 44 Degrees C!! 2 degrees lower than it was idling on the original stock heatsink. That is quite cool.

Also in this different case the Jet 7 isn't as noisy at all. I've currently got the fan speed turned up to full on it and it is no louder than the original CPU fan was. So all is great. Plus as this is the first day with Arctic Silver thermal compond the temperatures should fall further over the next couple of weeks as the compond settles down with the heating up and cooling down of the system. I should expect another 3-5 degree drop in the temps. :)

Now on to newer systems.

My last main system, an Athlon 64 3700+ and a 4000+ always ran nice and cool and I was very impressed with the temps of that CPU. Idling in the high 20s and only ever going to the high 30s under load. And that was on a stock heatsink.

With the rebuild of the system last week with a new CPU the temps were a few degrees higher, idling at about 33 Degrees. I had just built my new main system and was impressed with the heatsink I'd used, so bought another for the Athlon 64 system. Am Arctic Freezer 64 Pro. These are huge heatsinks, with a big fan mounted on the side, with a special damping system to make the fan near silient. With this new heatsink fitted the idle temps have dropped to about 27 degrees, and the system noise level has falled right down. Plus as this new cooler has the newer 4 pin connector the motherboard can control the fan speed, instead of needing a dial mounted on the case somewhere.

And finally my newest system. This is running an Intel Core 2 Quad Q6600. With an Arctic Freezer Pro heatsink/fan cooler this idles at about 18 degrees, and I've yet to see the CPU temps go over 30 degrees. Now that is great! #

This all goes to show that using a decent thermal compound between the CPU and heatsink helps to reduce temps. But the most important thing is that not all CPU coolers are born the same. A decent after market cooler can make a huge different to CPU temperatures.

At the moment I would recemment the Arctic Freezer Pro for Intel systems, and the Arctic Freezer 64 Pro for AMD systems. These are great coolers for the price, which is below 20. They come with Arctic Silver compound already applied too.