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Spin hard drives down or leave them running? - Page 2

post #31 of 52
7/21/12 at 9:24am
Quote:
Originally Posted by Somewhatlost View Post

I am confused...
before, it appeared you were claiming that HDD's were somehow special magical beasties that did not suffer any wear from power/sleep cycling... which is obviously either insane or delusional...
but now, it appears that you admit they do wear when waking up/powering up, it is just not enough wear in a standard usage scenario to actually have any measurable effect on the drives life... which is accurate to the best of my knowledge...
I would probably go so far as to say that letting a drive sleep while not in use for extended periods of time (hours maybe, days definitely) probably might even help extend a drive's useful life in normal (well what the average HTPC/home user considers normal at least) usage, but really in something like 99.99999% of all cases, the drive will get replaced due to size or speed upgrades long before it fails regardless of sleepiness... (again in an average HTPC/home user environment... a datacenter could be a completely different scenario)
so just for clarity, what is assassin's official position?
A) HDD's are magical beasties that don't wear do to power/wake up?
or
B) HDD's are just like any other electromechanical device, and they do wear due to power/wake up, but that the wear from power/wake up is <= to the benefit of not wearing while sleeping (and the power savings are a huge bonus too)?
or
C) ???

C. I am not worried about it either way.
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post #32 of 52
7/21/12 at 9:45am
Quote:
Originally Posted by assassin View Post

C. I am not worried about it either way.
so then why comment?
Quote:
Originally Posted by assassin View Post

I doubt its true. Just like everything (it seems) in HTPC I doubt its been tested.
Quote:
Originally Posted by assassin View Post

Oh, and I am pretty sure that they are made of dragon scales. Seems as likely as some of the other preposterous things reported.

oh, never mind... this isn't going anywhere... I guess I have just been successfully Trolled...
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post #33 of 52
7/21/12 at 10:48am
Quote:
Originally Posted by Somewhatlost View Post

so then why comment?
oh, never mind... this isn't going anywhere... I guess I have just been successfully Trolled...

I am not sure why you are getting so upset about this.

I never said there was no wear. I did say that it has never been tested compared to continuous use (spinning). Its likely a difference that is likely not statistically significant (if at all). And for HTPC I think its a non-issue. So use your hard drives however you like and don't worry that using them 2-3x per day might wear out their life expectancy because there is no real proof that this is the case.

Just enjoy your movies.
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post #34 of 52
7/21/12 at 11:29am
/first-world-problems
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post #35 of 52
7/22/12 at 7:08am
I leave mine running all the time because I do TV recording which could potentially cause a lot of spin ups and downs and I remember reading something a while ago that claimed hard drives (at least those used in Tivos) were designed to spin all the time. However, I did recently get a new WD Green drive with "Intellipower" that seems to spin the hard drives way down anyways regardless of the Windows setting because it occasionally takes it a few seconds to initially respond. I don't know if it will ever be feasible or affordable but I'm looking forward to multi-TB SSDs so that we won't have to worry about spinning at all...
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post #36 of 52
7/22/12 at 8:55am
The cost difference between flash and magnetic media is a step called photolithography where magnetic media is made with no pattern or format. Then pattern or format is put down later. This eliminated costly equipment such as stepper, etching and coatings. Magnetic media is facing technology barrier where lithography has to used; may be in another 10 years or so after patterned data and HAMR generation. This is when small magnetic islands has to be built on surface of the media. NAND flash will also face technology barriers in the sub-20nM features. intel just invested in ASML again to assure development of the next generation steppers.
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post #37 of 52
1/18/13 at 12:29pm
spin down = idle ??? When they post specs for power consumption ???
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post #38 of 52
1/18/13 at 1:53pm
Yes, spun down disks are using their idle power consumption figures
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post #39 of 52
1/18/13 at 2:15pm
The data you are looking for is the "load unload cycle count". You can read this from the SMART data on your disks to get their history, and you can also look up what your drives are rated for on their spec sheets.

If you want a real answer to your question, you'll need to crunch some numbers. What does your recording schedule look like? What kind of load are you putting on your drives? Calculate the cycles per day and extrapolate. Alternatively, you can just turn on drive spindown and wait a week and see how much your SMART data changed. Multiply by how long you expect the drive to last.

If you just want a rough guideline for a home server that's mostly just recording shows and playing them back, look at the drives spec sheets. If they are rated in the 300K range, (i.e. WD Green), then leave them running. If they are rated in the 1M+ range (i.e. most 2.5" drives) then turn on spindown.
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post #40 of 52
1/18/13 at 2:29pm
With a bit more searching, it sounds like a 3.5" hard drive typically uses 10-15 watts while spinning. Using this calculator, I found that 4 hard drives spinning constantly at 15 watts each would use about $4.75/month. That's not too bad.

Double that price if you are also running AC. When an array is doing more storing than serving, there comes a point when it's cheaper to aggressively spindown drives and replace them sooner than it is to keep them cool.
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post #41 of 52
1/18/13 at 2:43pm
Quote:
Originally Posted by EricN View Post


Double that price if you are also running AC.

And half it when the heat is on.
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post #42 of 52
1/18/13 at 2:49pm
This thread's last post (up until Mfusick's question today) was about 6 months ago. What are you referencing?

Also, FWIW, WD Green Drives spin down a lot and pretty quickly on their own without any OS intervention
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post #43 of 52
1/18/13 at 6:29pm
Think of a hard drive like a car engine. Everybody knows you get better gas mileage when driving at a constant speed. When you're constantly stopping and starting, your gas mileage suffers noticeably. The same goes for your hard drive. If it's spinning at a constant rate, it uses less energy. If you're constantly spinning it up and down it's going to use more energy. It's been over 40 years since I took college courses in statics and dynamics, but I do recall that it requires more energy to develop the inertia required to reach a certain speed from a dead stop than it does to maintain it once it's acquired. Temperature also plays a major role in the lifespan of a hard drive. If it's operated at a constant temperature over a long period it will suffer less than if it's constantly being heated up and cooled down. Constant expansion and contraction will take it's toll over the long haul.
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post #44 of 52
1/18/13 at 6:48pm
Quote:
Originally Posted by captain_video View Post

Think of a hard drive like a car engine. Everybody knows you get better gas mileage when driving at a constant speed. When you're constantly stopping and starting, your gas mileage suffers noticeably. The same goes for your hard drive. If it's spinning at a constant rate, it uses less energy. If you're constantly spinning it up and down it's going to use more energy. It's been over 40 years since I took college courses in statics and dynamics, but I do recall that it requires more energy to develop the inertia required to reach a certain speed from a dead stop than it does to maintain it once it's acquired. Temperature also plays a major role in the lifespan of a hard drive. If it's operated at a constant temperature over a long period it will suffer less than if it's constantly being heated up and cooled down. Constant expansion and contraction will take it's toll over the long haul.

I am not quite sure I agree with this analogy. Overcoming the inertia of something like a car is a whole lot different than that of something like a hard drive. Also you aren't taking in wind resistance and friction in to account which is a huge factor in cars/projectiles and almost non-existent in something like a hard drive which is self contained.

So you are saying that it takes less energy to drive constantly at 40 mph for 24 hours straight than to rest at 2 mph for 22 hours (hard drive at idle) and then accelerate to 40 mph for a few seconds (which is only a few extra watts for a few seconds) and then maintain a speed of 40 mph for 2 hours (the average length of a movie)? I am not buying that at all.

Am I understanding your analogy correctly? Where do I have it wrong? I think for a HTPC software based server this is where this type of hard drive works very very well. For a hard drive that is constantly accessed (like at a business or even home office) then it isn't as good of an option.
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post #45 of 52
1/19/13 at 5:31pm
Quote:
Originally Posted by assassin View Post

I am not quite sure I agree with this analogy. Overcoming the inertia of something like a car is a whole lot different than that of something like a hard drive. Also you aren't taking in wind resistance and friction in to account which is a huge factor in cars/projectiles and almost non-existent in something like a hard drive which is self contained.

So you are saying that it takes less energy to drive constantly at 40 mph for 24 hours straight than to rest at 2 mph for 22 hours (hard drive at idle) and then accelerate to 40 mph for a few seconds (which is only a few extra watts for a few seconds) and then maintain a speed of 40 mph for 2 hours (the average length of a movie)? I am not buying that at all.

Am I understanding your analogy correctly? Where do I have it wrong? I think for a HTPC software based server this is where this type of hard drive works very very well. For a hard drive that is constantly accessed (like at a business or even home office) then it isn't as good of an option.
Obviously my analogy isn't perfect as I was trying to keep it as simple as possible. Consider having to travel a specific distance in your car. If you travel the distance on a highway at a steady speed then you'll use less gas to get there vs. traveling the same distance via roads that have traffic lights at every intersection. There's also less wear and tear on your engine. The hard drive analogy is that letting the drive spin at a constant rate 24/7 will probably cause less wear and tear than a drive that's constantly spun up and down over that same period. Of course, if the drive is only spun up occasionally then it will probably last longer than the drive that's running continuously. You have to evaluate how the drive will be used and then decide which scenario will work best for your situation.

For example, I leave my primary PC on 24/7 because I access it constantly when I'm at home and use it for downloading torrents and such while I'm away. It would make no sense for me to shut it down or put it to sleep in between uses because I access it so frequently. Now, if I only turned it on once or twice a day it would make sense to shut it down when not in use.
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post #46 of 52
1/19/13 at 7:36pm
Quote:
Originally Posted by captain_video View Post

It would make no sense for me to shut it down or put it to sleep in between uses because I access it so frequently. Now, if I only turned it on once or twice a day it would make sense to shut it down when not in use.

Which is exactly what both many software raids and green/5400 drives do when you have multiple drives that aren't in use (also most black/7200 drives fwiw). Which is why I think they are fantastic for HTPC or storage and probably why I haven't had a drive fail yet in my HTPC and HTPC server whereas in my desktop I have replaced multiple standard drives that are used in a typical fashion.

I also find it interesting that some view something that spins constantly and generates more heat as a result as potentially having less wear than something that is at rest most of the time with intermittent starts and stops. I am not sure that there is clear data that one of these is significantly different/better/worse than the other. I can see both sides of this argument and my guess is that if it was studied it would probably be a wash or close to it.

My $.02.
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post #47 of 52
1/19/13 at 8:00pm
I think of it this way. Laptop drives.....

You close your laptop lid and the drive shuts down. You open the lid and it starts up. Now...how many times do you typically do that to a laptop?? smile.gif

Now, obviously we are not using laptop drives for storage...we're using desktop drives. However they are built identically. A laptop drive has smaller/less platters than a desktop drive, but the motor is smaller as well. As far as I know, the density on the platters is the same in both cases, the platters are just smaller in laptop drives.

I suspect that if an extended study were to be done, it would probably be a wash, as Assassin said.

My main storage server (obviously) has a lot of drives in it, however, it does not get used when nobody's home, or accessing it remotely, which is most of the time. It only gets used in the evening. The same applies to my HTPCs. The only thing that is constantly on in my setup is a small ITX based system that uses a 750GB laptop drive and that consumes ~20w while working. Everything else is in S3 sleep most of the time consuming ~2-4w. As soon as you fire up an HTPC, it wakes up the TV server, the storage server etc... all automatic. smile.gif
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post #48 of 52
1/20/13 at 4:47am
Quote:
Originally Posted by assassin View Post

I can see both sides of this argument and my guess is that if it was studied it would probably be a wash or close to it.
Yep, you're probably right. Hard drive reliability is all over the place so it would be difficult to cull any meaningful data from extended use. Some seem to last forever whereas others die right out of the box.
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post #49 of 52
1/20/13 at 7:31am
Quote:
Originally Posted by captain_video View Post

Yep, you're probably right. Hard drive reliability is all over the place so it would be difficult to cull any meaningful data from extended use. Some seem to last forever whereas others die right out of the box.

This is my observation and feeling as well.

I've been buying HDDs for 20 years and I have over 50 HDDs running in different places. (My office, my home, my server, pcs I built for friends and family).

I have over 20 in my house personally.

There's no common sense to be made regarding predicting HDDs and failure. They all fail at some point anyways. I just accept this.

It's interesting that failure data on some drives is higher than some others but that doesn't mean if you bought one it would likely fail.

The odds are always on your side it will work.

I buy on price per GB first then just blend the remaining issues into a feeling or purchase decision.
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post #50 of 52
1/20/13 at 7:36am
Quote:
Originally Posted by EricN View Post

With a bit more searching, it sounds like a 3.5" hard drive typically uses 10-15 watts while spinning. Using this calculator, I found that 4 hard drives spinning constantly at 15 watts each would use about $4.75/month. That's not too bad.

Double that price if you are also running AC. When an array is doing more storing than serving, there comes a point when it's cheaper to aggressively spindown drives and replace them sooner than it is to keep them cool.

I don't own any drives that consume 15 watts each constantly ...

You high on these numbers. Only on "spin Up" is the wattage consumed that high I think.

It's more 5-9 watts in average today. If cut your costs in half for a more realistic assessment.

Only if you have 10+ drives is the difference in energy from one HDD to another an issue. on a few HDDs the differences between drives doesn't equate to any significant monetary issue.
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post #51 of 52
1/20/13 at 7:38am
On issue of spin down vs leave running I don't see any real significant data either way..

I think it's a wash. There's many other reasons HDDs fail besides spin down or actually reaching wear cycles and wear out.

I'd spin down just to save the energy and heat and noise.
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post #52 of 52
1/22/13 at 12:10pm
Quote:
Originally Posted by EricN View Post

The data you are looking for is the "load unload cycle count". You can read this from the SMART data on your disks to get their history, and you can also look up what your drives are rated for on their spec sheets.

If you want a real answer to your question, you'll need to crunch some numbers. What does your recording schedule look like? What kind of load are you putting on your drives? Calculate the cycles per day and extrapolate. Alternatively, you can just turn on drive spindown and wait a week and see how much your SMART data changed. Multiply by how long you expect the drive to last.

If you just want a rough guideline for a home server that's mostly just recording shows and playing them back, look at the drives spec sheets. If they are rated in the 300K range, (i.e. WD Green), then leave them running. If they are rated in the 1M+ range (i.e. most 2.5" drives) then turn on spindown.

Some of the 1 million ratings are puffed up marketing though.
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