In a recent blog of mine “Hot outside, hot inside too”, I reported on the effects of a failed air conditioner on the temperatures inside my PC. Now that repairs on complete and things are back to what passes for normal around here, I thought it might be interesting to see how current temperatures compare. Incidentally and interestingly, it seems my memory of how my PC works and how it actually works are reasonably close, if not completely in agreement.

With the AC working again here’s what Franck Delattre’s HWMonitor.exe reports on that box:

With ambient temps on the wane, temps inside the PC also decline.

Here’s a comparison of what showed up in the last set of readings, as compared to this one (all temps are in °C; the MemErr column compares my recollections of normal temps in the “Hot outside, hot inside” blog to my readings for those newly-restored normal temps in this blog):

Item WithAC NoAC MemErr
TMPIN0 47 50 -1
TMPIN1 27 31 0
Cores 32-43 36-50 +7
GPU core 48 51 -1
SATA 160 34 37 0
SATA 320 36 39 0

Even though I was a little bit off for a couple of the readings, the difference in ambient temperture does seem to translate pretty directly into differences read by HWMonitor–at least at the low end, where ambient cooling and temperatures will have their greatest effects. I don’t worry much about core temps, as long as readings stay below 55 °C for the TMPIN0 sensor at the CPU socket and individual core temps stay below 60° C as well. TMPIN1 is the internal case temperature, and appears to be even more sensitive to ambient temperature than device temperatures, which makes sense to me from the standpoint that the temperature of the air inside the case is likely to be cooler than that for any device simply because there are enough fans inside there to keep outside air circulating from the intake fans and out the exhaust fans.

In case it isn’t incredibly obvious, even a modest ambient temperature difference makes a big difference for both human comfort and PC operation. The difference between 79 °F and 84° F (26.1/28.9 °C) is pretty small, but the difference between a small amount of cool air moving at a slightly lower temperature and no air moving at all at a somewhat warmer temperature is perceptually pretty extreme. The difference in ambient temperatures was 5 ° F/2.8 ° C, and translated into nearly the same difference between the two sets of temperature readings, both actual and remembered.