What about 18 times (150ms)? In my experience, the 1TB and larger S-brands always have a few sectors needing at least 18 spins to read, yet they're never marked bad, while the W&H brands never have sectors that slow (or the were marked off during manufacture). This is with MHDD, a DOS diagnostic.
What I meant was every ≥1TB Samsung (F1 and F4 HD204UI) and Seagate (7200.11, 7200.12, and green) had a few sectors needing between ≥150ms and <500ms to read, while the slowest sectors of the WDs (1TB EADS, 2TB EARS Black and Green) and Hitachis (1TB 7K1000.C, both 3EA and 3MA firmware) required <150ms, at worst. Also odd: MHDD never gave the same LBA numbers for those ≥150ms sectors. IOW those LBAs varied slightly on each pass. I don't know about the faster sectors since MHDD doesn't list their LBAs.I am assuming S brand is seagate, W is western digital, and H is hitachi?
so you say that with MHDD you see sectors requiring over 18 retries but not being marked bad with seagate, but not with WD and hitachi? interesting observation, it could be an issue with seagate drives in general or a specific model / firmware having a higher threshhold before they mark a sector as failed, what model was it specifically that you had tested this with?
10 years ago, Maxtor introduced a line of video media drives designed to reduce dust-related failures by having a head only on the bottom bottom side of the platter. Unfortunately those drives were unreliable for other reasons.
For some reason i thought that there is vacuum where the heads and platters move. Is there?
For some reason i thought that there is vacuum where the heads and platters move. Is there?
10 years ago, Maxtor introduced a line of video media drives designed to reduce dust-related failures by having a head only on the bottom bottom side of the platter. Unfortunately those drives were unreliable for other reasons.
Chief reason bolded, in red.
Seriously I cannot remember when Maxtor made a reliable disk. Way before Seagate acquired them. At least they left Quantum alone (SCSI) when they purchased them. Maxtor SCSI drives have been quite good. (although we purchase nothing but Fujitsu SAS disks now for mechanicals.)
Air is absolutely necessary for proper operation of modern hard drives because their heads literally fly over the platters on cushions of air. Without air, the heads would be firmly pressed against the platters by the springs on their head arms.For some reason i thought that there is vacuum where the heads and platters move. Is there?
Air is absolutely necessary for proper operation of modern hard drives because their heads literally fly over the platters on cushions of air. Without air, the heads would be firmly pressed against the platters by the springs on their head arms.
Not the HD, but you could give hints to the filesystem. Cf badblocks.Can you remap a HD to select out slow responding sectors?
Air is absolutely necessary for proper operation of modern hard drives because their heads literally fly over the platters on cushions of air. Without air, the heads would be firmly pressed against the platters by the springs on their head arms.
Got it. It makes a lot of sense. But wouldn't it be better if they found a technical solution where air is not needed? For example air causes friction and slows down the platters and heads, or it requires more power to move them. Has anything like this been tried? Except for SSDs of course.
Come on, you can do it. You are hell of a smart people here.
Actually the first hard drives didn't need air to operate because their heads were held away from the platters mechanically. Unfortunately that required holding them much farther away to prevent head crashes, making the magnetic field weaker and the bit density lower. That's why IBM invented the modern disk drive with flying heads, to let the heads operate much, much closer to the platters and thereby strengthen the magnetic signals, but that also required air and a dust-free environment.Got it. It makes a lot of sense. But wouldn't it be better if they found a technical solution where air is not needed? For example air causes friction and slows down the platters and heads, or it requires more power to move them. Has anything like this been tried? Except for SSDs of course.
I opened an old Western Digital IDE 40Gb drive which i have used for long time. It developed bad sectors few years back so i stopped using it. Now, since it doesn't do any good i opened it up yesterday. Of course the platters were perfectly clean but i didn't notice any scratches or traces of wearing off. I also took out the air filter which is supposed to capture internal debris and it was totally clean as far as good eye can tell. Are those debris supposed to be invisible to naked eye or there aren't any?
I tried turning it on (using an old AT PSU) but it didn't turn on. Guess there is some protection so it doesn't work when opened so you don't lose your skin if you touch the rotating platters. Instead there was a sort of squealing. I tried turning it on with another PSU but the same squealing happened. I unscrew one of the platters and gave it to my baby girl to play with since it was all shiny and reflective. She liked it very much lol but lost interest in it soon.
Actually the first hard drives didn't need air to operate because their heads were held away from the platters mechanically. Unfortunately that required holding them much farther away to prevent head crashes, making the magnetic field weaker and the bit density lower. That's why IBM invented the modern disk drive with flying heads, to let the heads operate much, much closer to the platters and thereby strengthen the magnetic signals, but that also required air and a dust-free environment.
Also, I wouldn't really recommend giving the platters to children (young at least) the lubricant they use isn't exactly child friendly (especially to little ones who like to put everything in their mouth).
Platters make very nice mirrors too. :biggrin:
Yea, especially for those who don't have the slightest idea what that is or where does it come from