You'll definitely hear a difference with a new drive. I picked up an iMac G3 Snow for $5 and the drive was so noisy, changed it out for an 80gb drive (after some issues with a bigger drive) and it's super quiet now.
Oh, I forgot to mention in the other thread, I used a 120GB WD with 20GB off partitioned for OS 9 successfully in a pink iMac G3 DV, some years ago, the rest had OS X on it.
Oh snap, I think the smallest IDE I have is ~150Gbs, they can't go over 200Gbs correct?
Hmm, I need to check my SMART stats, glad my CRT isn't failing, as said before, it is REALLY bright.
If you read that 200GB limit in the other thread (where Ih8reno asked), I was referring to this doc
http://support.apple.com/kb/HT2544 that says, under 9.2.2 you have to make no partition bigger than 200GB,
IF in the first place your Mac supports drives over 128GB. The iMac G3 does not. Apple says in the document above, that all models before June 2002 don't, to make the info complete here (for other users and later reference), it is some Quicksilver PowerMac G4s that do and don't support it, it depends not only on the production/introduction year, but the Motherboard used, which one read here
http://www.macos9lives.com/mac os 9 lives_003.htm
The above OS 9 link has also a lot of other OS 9 fun (including tips about software and free stuff. Since you already have 9.2.1 you will be allowed to use the free 9.2.2 Update by Apple. The index in the Apple support database is still existant, but if you click on the link for "english", you get an error. In the OS 9 forum you can ask/find how to upgrade still.
On the 128GB limit in Macs before 2002, people often mention the Hi-Cap "driver" by Initech (a firmware thing). Intell said, that this does not work in iMac G3s. Here they don't say it won't work
http://lowendmac.com/2005/how-big-hard-drive-imac-emac-power-mac-powerbook-ibook/ they only say big drives do not make sense to buy the Initech driver, since you have the same speed as with booting from an external Firewire400 drive, for an iMac because of the ATA33, but your model is an iMac with ATA66 anyway
If you use a 160GB HDD to use the full 128GB possible, put the HDD in your Mac and then format it with an install disc. I was told some time ago, that the drive will make problems, if you partition only 128GB of it in a Mac that supports big drives and then use the drive in your iMac. Also, Hitachi once told me to better not use a 160GB drive in a Mac with 128GB limit, because files used for the system could be written in the part of the drive that is not seen, and that could cause problems or even prevent it from starting the next time. I am not sure, how they come to say this, maybe they mean, if one formats the whole 160GB and then puts it in a 128GB-limit-Mac afterwards, were only the 128GB will be seen, but there is a hidden part that theoretically per HFS+ is writable. Still not sure, why the Mac should write to that area then... *wondering/head-cratching-smilie* (the new "confused" smily looks very mean on a 12" display...
) (it was talked about here
https://forums.macrumors.com/posts/12710831/)
Oh, also OS 9 has to be in the first partition, if you have another for OS X, too. Some say, this only applies to tray-load iMacs (others might confirm!) and I read that the picture in disc utility shows the 2nd partition as the upper, right? or was it the other way round? So long since I had to know that.
Or do you mean in what sizes the HDDs are available? There was another thread recently, that mentioned that. The biggest build was a 500GB 3,5 PATA HDD. Seagate build a rare 750GB PATA HDD. What I didn't know before, it seems Samsung had a 400GB SATA HDD with a PATA connector for OEM stuff.
But if it is true, that you can't use the Intech driver and no big drive, the biggest you will look out for will be a 160GB (discarding the rest ofer the 128GB) or a 120GB HDD.
Since some have become expensive, you might want to use a cheaper SATA drive (2,5" will work, too) and use a ATA-SATA adapter.
How does one discover how many hours are on the drive?
Install Volitan SMART Utility, it is free for the first 5 uses or 28 days, what ever comes later. SMART Reporter is free for ever, but I found it not warning me about drives that were really at the end of their lifes with many errors. Both have a GUI and you don't need terminal commands.
