My wifes machine has 3 HD's installed in it. They are all in the 3 by 3.5" bays stacked one on top of he other. Last weekend the power supply blew ( a capacitor popped after a power failure). After replacing the power supply I noticed that after several hours running the HD's were very hot to the touch. As I mentioned they are mounted one above the other with only a few mm between them. What sort of temps can an HD take? I don't know the actual temp but you wouldn't hold your hand on the for long. Maybe 35C or so? Also I noticed with the new quiet power supply that the major source of noise form the unit was actually resonance from the HD's. I lessened the noise considerably by loosening off the HD mounting screws. I was wondering if I should take out the middle HD and get adaptors to mount it in a 5 1/4" bay above the cdrom and/or an extra fan to cool them down. Any comments would be much appreciated. This system has 'evolved' from a single 20 gig HD with the addition of 2 more 40 gigs since it purchase in early 2000. It is our Internet gateway with its USB ADSL modem running 98se (3 x 256meg ram) and internet connection sharing on our LAN. The storage is for the 13,000+ mp3s. :) Again thanks in advance for all comments. Thanks in advance "Two roads diverged in a wood, and I - I took the one less travelled by, And that has made all the difference." Frost

Hard drives can become hot to the touch. This is not ideal but also not necessarily error-inducing. I've never experimented near the limits of specifications - naturally, I would avoid it. The best situation is a larger case with more fans, particularly a sidemount. Moving dead air and avoiding compact space are two basic ways to cool components. Adjacent devices can heat the still air between them. If you could move that air closest to the hard drive (or any offending device) just a little, it would lower the peak temperature. Likewise, if you could seperate those devices, the air between them would become less of a warming cushion. I would try mounting the drive above the CD-ROM and adding an extra fan. I'm sure there's some program that samples your hard drive temperature.

If your harddrives have sensors , and a lot do then Speedfan is one program to get that will let you know what's going on with temps. Google for it. I haven't seen anything on maximum internal operating temp for harddrives but specs I have seen indicate they will operate normally in ambient temps up to 65degC. If the rest of your box is at that kind of temperature you would be able to smell the smoke. That said, do as suggested above. Separate the drives and instal an extra case fan or two to get some airflow going. Give a man a fish and you feed him for a day. Teach him to fish and you feed him for life.

Another way to keep the drives cool is by changing the power options to turn off the two secondary drives after about 30mins and C:\ to turn of after about 45mins or an hour. This will also minimise noise. Mattwizz3

Definitely a good idea to move the middle drive.

Good advice above...and don't worry too much about finding a place to mount a fan. Glue it, ziptie it, hang it from the cable. Anything to get a little air flow where the drives live. That little bit of airflow will cut about 10°C off the drive temps and the added reliability is worth the effort. Skip

follow post 5's advice and they will get cool enough. 55c is the rated max temp for a 7200rpm drive, but anything over 45C stresses the drive and can shorten its life. Low 40s or below is fine.