thad@cup.portal.com (Thad P Floryan) (11/08/90)
A question arrived in email asking about one aspect of HDs that I never considered before: NOISE. Enclosed is my response since this subject may spark additional discussion. Thad -------------------- I'm probably not the best person to ask about noise levels since my hearing isn't all that great, but even I can hear the HDs on my systems. Without exception, ALL the ST-506/412 high-performance and/or large capacity HDs I've encountered are "noisy". The ol' 65mS 20MB clunkers are generally quiet since the parts therein simply don't move all that fast. The quietest drives I've encountered are the Quantum SCSI units (specifically their 80S and 105S), but, alas, that's not an option on the UNIXPC. As for absolute sound levels, that can be measured, but remember this: it can be statistically proven that an OLD 8-pin dot-matrix printer has a lower average sound level than a modern laser printer since the dot-matrix printer is absolutely quiet when it's NOT printing whereas the fans and thermal switches and heaters in the laser printing are always operating! :-) If noise is a problem (as it is in my music room), my solution was to get a modern terminal which uses only convection cooling (i.e. no fans, etc.) and use that terminal in that room and run the RS-232 cabling clear across the house to where the computers are located (I need access to my "music" database in the music room, natch!). External HD cases by themselves are not a solution since they contain a fan, and the front panel of the HD is (typically) exposed permitting any HD noises to be focused right out the front of the case after being resonated and acoustically amplified by the case itself. Now, if you're industrious and don't mind experimenting, here's one idea based on the fact the RS-422 signals (to/from the 26LS31/26LS32 drivers and receivers interfacing the HD signals) can drive out to 20 feet: get long cables and locate the HD(s) in another room where the noise won't be bothersome. I've run my SCSI cables (on another system) out to 20 feet (the SCSI spec permits this), and all docs I've read re: ST506 interfacing indicate its drivers will also go to 20 feet. Of course, you undertake this experiment at your own risk. Be SURE to backup all HD data before trying anything like this. I'm at a loss for additional ideas since there doesn't appear to be any way one can soundproof the UNIXPC without blocking critical air vents. But you may try placing the system on a "typewriter" foam-cushion sound pad and see if that makes any difference; I still believe the clacking sounds of the HD during operation will still emanate from the main part of the case, so the net gain may be nil. Thad Thad Floryan [ thad@cup.portal.com (OR) ..!sun!portal!cup.portal.com!thad ]