I'm really happy for anyone who is not plagued by high pitched whine! However, the question always remains, is there in fact no whine or is it only not heard? Keep in mind that this type of noise is usually very directional, which means you can not hear it at all in some cases, however that doesn't mean the drive isn't emitting it. I know excellent samples exists so I'm not insinuating anything. In addition to sample variance there's also lots of other variables including ambient noise level and acoustic properties, source distance, angle, position, hearing ability... Well, in short let's just say it takes one hell of a forum post to convince me
My P120 250GB and a friend's P120 200GB I got to test have clear high pitched whine. SPCR's 4 recordings of P80 and P120 samples all have it. Every 7200rpm 3.5" drive I have around (which is over 10 drives) are suffering from it, except for one. The most notable of the drives are the old Barracuda IV and V drives and a new Caviar SE manufactured only 4 months ago, which all are supposed to be so good. Both Barracudas are piercing but I admit the new Caviar is pretty good overall plus it's a little lower in pitch than the others but still far from acceptable to be used bare. Let me tell you something else, I recently tested a 7200.9 40GB drive thinking it would be special because it's specced at 2.0 bels idle! Overall sound power was indeed very low, but guess what? It has the high pitched whine too, real bad I might add, fortunately the disappointing test didn't cost me anything.
I have a 3.5" 5400rpm drive which I'm pretty sure won't even be considered but I'll just mention it anyway. It's a Seagate U Series X 10 which is a CE market drive extracted from an Xbox console. It's the quietest 3.5" drive I've heard in idle, and no high pitched whine, even against this background the seeks are still very quiet and soft, it has basically no vibration at all and it also runs very cool. It's extra low profile too and the height is 20mm instead of the standard 26mm. Too bad it's only 10GB, even so it's actually not much slower than a Barracuda IV! Anyway, the model number is ST310014ACE.
For capacity and performance reasons I replaced that drive with the very best 3.5" 7200rpm drive I've come across. The drive has the lowest noise level overall and there's nothing high pitched about it. The vibration is extremely low as well. The sound comes off as a nice broadband whoosh if not concentrating and focusing on hearing the borderline audible mechanical noise. AAM is permanently enabled and the seeks are discreet. It's the only replacement that I found acceptable for using bare in my Xbox (which is modded and has a silent 80mm fan). It's so good that whatever faint motor noise there might be it's so weak in volume that it gets completely blocked by the Xbox chassis, only some of the quiet white noise makes it through to the outside of the case. Also, low frequency hum is nonexistent even though it's just hard mounted in the standard plastic drive bay. The drive in question is a single platter Barracuda 7200.7 80GB PATA drive made in China, model number ST380011A.
Didn't mention this drive before because it's not commonly available anymore and it's not SATA so I guess it's off the list. It's now among the retired ones of the Recommended Hard Drives
. However if PATA is OK it should still be considered, if you can find it.