Variable HD speed?

[benz]

This might be a n00b question, but I'm gonna go ahead and ask it, since I can delete this thread if it is.

Can you change the speed at which your hard drive spins at? For instance, say I have a 60gig 7200rpm drive in my thinkpad, and I think its being too loud/hot/etc....can I set it to run only at 5400 or 4200? Would this be a software setting that can be manipulated without restarting? Or would it require messing with the BIOS?

[Sci-Clone]

I don't knwo if its possible (because the motors are desegned to run faster). But if it is possible this would be a great idea! How come I've never though of that! Good job!

Actually thinking about it. I think physically this could happen because the drive rotates faster or slower according to which sector it is reading/recording. I guess all you need is program that can crontrol that.

[benz]

Yeah, I am aware of the fact that they don't spin at a constant speed, as it depends where on the platter the head is.

On a side note, when a drive is advertised as 5400 or 7200 rpm, does it means that that's the max rpm it can attain? or the min?

Either way, the faster drives should be able to 'scale' down, so to speak. Kinda like speedstep, but for a HD.

[Sci-Clone]

Im pretty sure that that is the maximum speed they can reach. I doubt that companies would advertise the minimum speed that their products have. They always round it up. Like the 400MHz front side bus. It is actually approximatly 399MHz. Or when I bought an iPOD mini for my girlfriend. It is advertised as 4Gb but there are actually 3.7Gb available

[G-Man]

Actually you can scale down the speed a little by disabling "write caching on the disk" in Device manager>HD>Policies... but who the hell would do so? Unfortunately there is no "speed up" option.

Regards,
G-Man

[Chun-Yu]

Yeah, I am aware of the fact that they don't spin at a constant speed, as it depends where on the platter the head is.

Actually, I'm 99% certain they do spin at a constant speed. Think about it - why else would read/write performance typically be higher at the beginning of the drive? Because the beginning = outer edge (unlike a CD), which passes by the heads faster than the inside does.

[Sci-Clone]

The speed in which the needles can write is constant. So if the speed of the drive was cosntant also, lots of physical space of the hard-drive would be wasted. It's like a bike wheel. If the speed of the hard-drive was constant, it could only write stuff on the "spikes" and nothing in between. But I could be wrong. I just remember my professor saying (A couple of years ago) when the hard drives had constant speed and all that space was being wasted.
Maybe someone with more understanding on the subject can explain better.

[awolfe63]

Hard disks spin at a constant speed. DVD and CD drives generally do not.

[cynic]

The platters spin at constant speeds.

see here for the best reference page on hard drives and hard drive technology (storagereview.com) It can answer any question on hard drives (well, as many as I've thought about...)

[Sci-Clone]

I guess you guys are right.
Sorry If I confused anyone about it. It's my professors fault

[benz]

So the answer to my original question is basically no? Is it physically impossible or are we just lacking appropriate software to do the trick?

[jdhurst]

I think you may be missing the point on the fast 7200-rpm hard drives. I have had three: Number 1 failed as a result of the Airbag failure; Number 2 is a purchased replacement working in my T41 ThinkPad now; Number 3 is the warranty replacement not currently in regular use. All three drives have been cool, smooth, quiet and vibration free. Somehow the current drive gets quieter as time goes by. It just sits and spins its heart out and I *never* notice it except for this: When I want an application, it comes up *much* faster and more smoothly than a 5400-rpm or 4200-rpm drive. So why do you need it to run slower? It would ruin the major performance benefit. If it is noisy, hot and vibrates, consider getting it replaced. ... jdhurst

[benz]

That's good to hear. I guess I've been reading too many of those "7200rpm hard drives are hot loud vibrate etc" threads/comments. I'll just have to see how mine does when I get it. Thanks for the replies people.

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