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luffytubby

macrumors 6502a
Original poster
Jan 22, 2008
684
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if you are downloading a lot of files, I've been told that its best to do it on an external drive and not your main OS drive, because it wears down the efficency of the drive. Is that true?


And if so, and you want to keep the longevity of your drives as good as possible, is it best to download to a slower drive(with less rpm) or a faster raid-zero thunderbolt drive?
 
Downloading does not wear down the internal or external platter based HDD, unless you talk about TBs on a daily basis.

If you download several GBs per day, it is best to use an external HDD in order to leave the system HDD to its own, thus the system HDD has enough "time" to process its own work (temporary files and such).

A RAID is not needed, a Thunderbolt drive or RAID would be overkill, unless you download at more than 80 MB/s. A USB 2.0 or 3.0 or Firewire 800 HDD should do just fine.
 
if you are downloading a lot of files, I've been told that its best to do it on an external drive and not your main OS drive, because it wears down the efficency of the drive. Is that true?
It doesn't wear down the efficiency of the drive. Drives have a limited lifespan but the lifespan that you'll get will vary. Heat and constant reading and writing can impact drive life but odds are unlikely that the usage you're thinking of will have significant impact.

As always: consider the source.

And if so, and you want to keep the longevity of your drives as good as possible, is it best to download to a slower drive(with less rpm) or a faster raid-zero thunderbolt drive?
Neither. It does not matter.
 
if you are downloading a lot of files, I've been told that its best to do it on an external drive and not your main OS drive, because it wears down the efficency of the drive. Is that true?
No, it's not true. Download all you want. You'll most likely run out of drive space or otherwise find your drive obsolete before you wear it out.
And if so, and you want to keep the longevity of your drives as good as possible, is it best to download to a slower drive(with less rpm) or a faster raid-zero thunderbolt drive?
It makes absolutely no difference at all.
 
Nobody's mentioned it really, but it's kind of true for SSDs, but at a very minimal level.
 
Nobody's mentioned it really, but it's kind of true for SSDs, but at a very minimal level.

Normally modern SSDs have a theoretical write/read limit of 10,000 to 100,000 cycles (P/E cycles), meaning if you had a 64 GB SSD and its cycle limit would be 10,000, you would have to write 625 TB to it, which would be 351 GB per day everyday for the next five years. Assuming those numbers vary and it would only be a tenth of that, it would still mean 35 GB per day, which under normal usage no average computer consumer does, not even with temporary files.
 
Whilst downloading won't "wear your drive out", as your drive fills up, the free space remaining will be slower as the inner tracks (NON-SSD obviously) don't read or write as fast - and in extreme cases the OS will not have enough free space to work with to keep files un-fragmented.

The more free space you can keep, the faster disk access will be.

This is most apparent when you start getting up near 80-90+ percent full.
 
Normally modern SSDs have a theoretical write/read limit of 10,000 to 100,000 cycles (P/E cycles), meaning if you had a 64 GB SSD and its cycle limit would be 10,000, you would have to write 625 TB to it, which would be 351 GB per day everyday for the next five years. Assuming those numbers vary and it would only be a tenth of that, it would still mean 35 GB per day, which under normal usage no average computer consumer does, not even with temporary files.

Yes, that's until the drive dies. However, it is well known that the vast majorities of SSDs do not maintain their performance after lots of cycles. They will still be serviceable, yes, but you wont expect to

Also, the way current MacBooks are configured - every time you put your computer to sleep, it writes the entire contents of RAM to the SSD "just in case". Now it's not uncommon to have 16GB of RAM these days, and I think it's fair to say that I close my laptop's lid anywhere from 10-20 times per day. That's 160-320GB of writes per day, just on sleep operations alone (personally I've disabled this "feature", but it's how they come configured out of the box).

Before you make sweeping statements, you need to understand some of the characteristics of the operating system that affects it.
 
Yes, that's until the drive dies. However, it is well known that the vast majorities of SSDs do not maintain their performance after lots of cycles. They will still be serviceable, yes, but you wont expect to

Also, the way current MacBooks are configured - every time you put your computer to sleep, it writes the entire contents of RAM to the SSD "just in case". Now it's not uncommon to have 16GB of RAM these days, and I think it's fair to say that I close my laptop's lid anywhere from 10-20 times per day. That's 160-320GB of writes per day, just on sleep operations alone (personally I've disabled this "feature", but it's how they come configured out of the box).

Before you make sweeping statements, you need to understand some of the characteristics of the operating system that affects it.

I know about the sleepimage, it is what made me bring my first x86 MacBook back (it took 30 seconds to go to sleep), since my iBook never did that. The people I brought it back to, an Apple Store, did not know, what happened with my MacBook. It was only after I did a search myself I came upon a tiny place called MacRumors Forums to find out why this happens.
Since then I am pestering people here about this and that.

But thanks for reminding me about the sleepimage issue, I totally forgot it when writing that little tidbit, I will update it. :)

Normally modern SSDs have a theoretical write/read limit of 10,000 to 100,000 cycles (P/E cycles), meaning if you had a 64 GB SSD and its cycle limit would be 10,000, you would have to write 625 TB to it, which would be 351 GB per day everyday for the next five years. Assuming those numbers vary and it would only be a tenth of that, it would still mean 35 GB per day, which under normal usage no average computer consumer does, not even with temporary files.
Also know, that with modern Mac notebooks like the MacBook Pro, MacBook, MacBook Air and G4 PowerBooks, Mac OS X writes the contents of the RAM to the HDD/SSD once the notebook is put to sleep, it is called the "sleepimage" (The Mac OS X sleepimage file explained) and is the same size as your RAM amount, thus 2 to 16 GB might be written to your Mac notebook's HDD/SSD every time you put it to sleep.
You can safely disable that sleepimage via Terminal or SmartSleep.
 
Normally modern SSDs have a theoretical write/read limit of 10,000 to 100,000 cycles (P/E cycles), meaning if you had a 64 GB SSD and its cycle limit would be 10,000, you would have to write 625 TB to it, which would be 351 GB per day everyday for the next five years. Assuming those numbers vary and it would only be a tenth of that, it would still mean 35 GB per day, which under normal usage no average computer consumer does, not even with temporary files.

I agree with your overall point, but your numbers are a bit outdated. Even "high end" SSDs now only use MLC NAND which has 3,000-5,000 write cycles. Many of the newer SSDs (like Samsung 840 non-Pro) use TLC NAND with only 1,000 write cycles.

Really good article here showing even with a TLC NAND drive at 10GB a day, it will last over 11 years.

So back to your point, yes... just use your SSD and don't sweat it. It will likely outlast the rest of your computer.

screenshot20130312at413.png



Yes, that's until the drive dies. However, it is well known that the vast majorities of SSDs do not maintain their performance after lots of cycles. They will still be serviceable, yes, but you wont expect to

Also, the way current MacBooks are configured - every time you put your computer to sleep, it writes the entire contents of RAM to the SSD "just in case". Now it's not uncommon to have 16GB of RAM these days, and I think it's fair to say that I close my laptop's lid anywhere from 10-20 times per day. That's 160-320GB of writes per day, just on sleep operations alone (personally I've disabled this "feature", but it's how they come configured out of the box).

Before you make sweeping statements, you need to understand some of the characteristics of the operating system that affects it.

You are mistaken. The sleep image is only written when your Mac portable hits the low battery warning so that system state can be saved to the drive if the battery dies. A normal sleep like many of us do several times a day does not write a sleep image.

All these "tweaks" everybody is doing on their SSD are completely unnecessary.
 
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