[How To] turn off HDD in less than 3 mins.

mb2 · Post by **mb2** » Fri Jul 14, 2006 10:01 am

Windows power options only lets u turn off your HDD after being idle for 3 mins or more.
with a bit of searching through the registry i've figured how to change the time to anything you want..

the key that is of interest is
HKEY_CURRENT_USER\Control Panel\PowerCfg\PowerPolicies\4

u can use any number at the end (they represent each power scheme), but this one is "Minimal Power Management", which means CnQ works on AMD cpus.

If u export that key it will look something like

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Control Panel\PowerCfg\PowerPolicies\4]
"Name"="Minimal Power Management"
"Description"="This scheme keeps the computer on and optimizes it for high performance."
"Policies"=hex:01,00,00,00,00,00,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,32,32,03,03,02,00,00,00,02,00,\
00,00,00,00,3d,77,2e,f2,07,00,58,02,00,00,2c,01,00,00,b4,00,00,00,84,03,00,\
00,00,00,64,64,64,64,91,7c

the bold bit is hex for the time in seconds for the hdd to turn off (when idle). oddly the 2 numbers on the right are a higher magnitude than those on the left. (maybe thats normal?)
So b4,00 is 3 mins. and 10 mins would be 58,02 (5x16 + 8 + 16x16x2 = 600 seconds).
So aslong as u can convert from decimal to hex then u can put in any time for your HDD to turn off. (1 min is 3c,00). change it and merge the file back into the reg.

Anyway, hopefully this is useful to someone.. with CF/iRAM/ramdisk/no pagefile.. but if u have a pagefile on a mechanical hard drive then its probably not a good idea.. as it would lead your HDD to constatntly spin up and down every couple of mins..
Shame u can't set it on a per hdd setting..

shunx · Post by **shunx** » Fri Jul 14, 2006 11:19 am

Is it harmful to the drive to turn it on and off often?

jaganath · Post by **jaganath** » Fri Jul 14, 2006 12:33 pm

shunx wrote:Is it harmful to the drive to turn it on and off often?

Yes. Think about it, if the hard drive is constantly spinning down and spinning up the spindle motor is constantly having to accelerate the disks from 0-7200/10,000RPM; not only is this wasteful of energy it puts a large amount of stress on the motor and actuator arm.

Arvo · Post by **Arvo** » Fri Jul 14, 2006 12:54 pm

And more harm - current FDB (fluid dynamic bearing) drives may suffer from frequent startup due to the platter vertical vibration. Such vibration may occasionally cause direct mechanical contact between magnetic head(s) and disk surface, which will destory surface fast.

I can't find link ATM, but I remember article about many Samsung (desktop) drives having destroyed their firmware tracks because of this - their head parking zone is near or above the firmware tracks. Unfortunately firmware sectors are the only ones, not reallocatable

I don't know about notebook drives, but probably they have much better resistance to frequent spin down/up.

inti · Post by **inti** » Mon Jul 17, 2006 2:30 am

Drive spindown optimising is a compromise between wear and heat for the drive due to constant spinning, and wear due to spin-down/spin-up. Like an aircraft in take-off, spin-up is the most stressful time in a drive's life (but obviously the stresses are not so huge)! Most drives are rated for 50,000 spin up events. That means that frequent spin up events should be avoided.

My own rule of thumb is that a drive should not be spinning up from idle more than 10 times per day. Therefore I find that setting spin down time at around 20 minutes works best for me. If I am working on the PC then it is unlikely that the drive will spin down within that 20 minute period.

To help the drives to spin down, I have on a ramdrive:
*Page file
*Windows/Temp folder
*application-specific temp folders
*Temporary Internet Files

I have switched off the following Windows Services: Indexing Service, System Restore, File Optimisation. I have no scheduled services. I have hacked the registry to disable the Windows "features" which (a) store in the registry the filename of every .exe which you execute; (b) update the 'date last accessed' attribute of every file you read.

This allows all my drives to spin down when the PC is not in use. When the PC is in use, the Windows is always spinning (I think any change to the registry causes file writes, but I am not 100% sure).

Unfortunately all spun-down drives have to be spun up when you want to Shut Down or Restart your PC, I have not found a way to disable that (which is stupid, and places stress on the drives as they spin up, shut down, spin up again within a couple of minutes).

And unfortunately many software applications (e.g. Zoom Player) like to check the volume label of every connected drive when the application starts, which causes drives to be spun up unless the volume label was cached.

A few applications fail if writing to a spun down drive, because although the attempt to write causes the drive spin up process to start, the application in some way has a timeout before the write operation is completed.

One other thing I've noticed: if you have open a window showing the contents of a folder on a spun down drive, if you move your mouse over that window (so that the tooltip showing the filesize of an individual file in that folder appears) then the drive will have to spin up.

So the take-home message is that Windows is not well designed to deal with spun-down drives.

HammerSandwich · Post by **HammerSandwich** » Mon Jul 17, 2006 6:28 am

Thanks for the excellent info, inti

inti wrote:To help the drives to spin down, I have on a ramdrive:
*Page file
*Windows/Temp folder
*application-specific temp folders
*Temporary Internet Files

That machine must SNAP!

mb2 · Post by **mb2** » Mon Jul 17, 2006 7:55 am

inti,

"I have switched off the following Windows Services: Indexing Service, System Restore, File Optimisation. I have no scheduled services. I have hacked the registry to disable the Windows "features" which (a) store in the registry the filename of every .exe which you execute; (b) update the 'date last accessed' attribute of every file you read. "
how do u do these reg hacks..
and does system restore really make a difference? surely it doesn't write anything unless there is a new/changed .exe or somethng.. so if u turn it off just for the ramdisk it shouldn't make any difference?
any more info on the file optimization?

i'd also suggest u put a copy of portable firefox (or portable opera, which i might swtich to..) in the ramdisk (copy it at startup with a .bat or such..) if u browse without doing a lot of other stuff..
there is software to copy the stuff back on shut down (or just use another .bat assuming u have XP pro)... if its gonna spin up on shutdown u may aswell make the most of it

and yea apps which start up all drives are pretty annoying, bearshare is another.. it starts up a drive i had connected which wasn't even seen by windows explorer? :s

i think what i may do is set the hdd spin down to something reasonable.. and then have a .reg in the start menu that will set the hdd spin down to a few seconds, effectively a hdd kill switch.. for when i know i wont be using it, anddd then have another to set it back to normal.. and impliment that by default at shut down..

any idea how to change the location of the start menu, as it spins the drive up when not cached..?

as for the temp dirs, any list of common ones (ie inc apps) / how to change them?

and yes, windows is terrible for anything but a standard setup.. everything in a ramdisk is again copied to the ram.. and is indexed or something that means anything in a ramdisk uses twice the space.. so uses 3 times the memory it actually needs to...
imo this will be much more of a problem when more unified memory stuff starts becoming prevalent.

Chrissicom · Post by **Chrissicom** » Thu Jul 27, 2006 10:40 pm

Shortly said, keep your computer running 24/7 it will greatly increasing its age

Turn Off/On does not only hard disks due to unecessary motor restarts, but also your optical drives reseek, your PSU is pushed to a Boot peak load, your CPU is suddenly stressed from 0 when you turn your PC on because there's no such thing as Cool and Quiet or Speed Stepping during Boot, etc.
Generally the less restarts you do the longer your components will live. Most computer parts are made to run 10 years 24/7, they are not made to be turned off and on 10 times a day.

shunx · Post by **shunx** » Sat Jul 29, 2006 5:45 pm

Chrissicom wrote:Shortly said, keep your computer running 24/7 it will greatly increasing its age .

Ooh does that also mean I can live longer if I work 24/7 and never sleep (as opposed to sleeping forever after a week)?

Chrissicom · Post by **Chrissicom** » Sun Jul 30, 2006 2:28 am

shunx wrote:
Chrissicom wrote:Shortly said, keep your computer running 24/7 it will greatly increasing its age .
Ooh does that also mean I can live longer if I work 24/7 and never sleep (as opposed to sleeping forever after a week)?

Hahaha

would be nice if humans worked that way as well

. Anyway I think SCSI drives are a very good example for the 24/7 thesis since they have even more MTBF than usual SATA drives but less startup cycles in many cases.