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Silly John Fatty

macrumors 68000
Original poster
Nov 6, 2012
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I'm planing to get an SSD in my next iMac, and I've read a lot on how they get slower because there's partially-filled blocks which take time to rewrite and things like this.

My question is just – is there something (a tool?) in order to make it as fast as it was on day 1 again? Or am I spending lots of money to have a drive slower than a normal HDD one year from now?

I heard of this TRIM function but apparently it only deletes blocks, but not partially filled ones.
 
I'm planing to get an SSD in my next iMac, and I've read a lot on how they get slower because there's partially-filled blocks which take time to rewrite and things like this.

My question is just – is there something (a tool?) in order to make it as fast as it was on day 1 again? Or am I spending lots of money to have a drive slower than a normal HDD one year from now?

I heard of this TRIM function but apparently it only deletes blocks, but not partially filled ones.

Enabling TRIM will do, and I have not noticed any slowdowns in my SSD. It still performs at the exact speed today as it was when still new.
 
I've never had a problem, I think people worry way too much about SSD minutiae.

Get one, go fast.
 
Having TRIM enabled is the best you're going to get with an SSD. It's an OS feature and works over SATA and ThunderBolt. All SSDs have internal Garbage Collection, which is part of the drive firmware and OS independent. TRIM and Garbage Collection are not the same thing. If you have TRIM enabled, you're doing all you can to keep your SSD optimised.
 
Just don't overfill it >80% and have TRIM enabled and you won't have anything to worry about.
 
Thanks guys. I've read that the SSD keeps 7% or so to itself which is not user accessible to not "overfill" it.
 
Thanks guys. I've read that the SSD keeps 7% or so to itself which is not user accessible to not "overfill" it.

Not all do, but yes, most do. That is called over provisioning and it is space set aside so that when some of the NAND cells get worn out they are marked bad and replaced by a cell from the over provisioned area. So even as some of the cells wear out the SSD still has the same amount of usable space.

The idea of keeping some space free is more related to keeping speeds up. Personally, I think 10% or so free is plenty, but there is no hard rule here.
 
Having TRIM enabled is the best you're going to get with an SSD. It's an OS feature and works over SATA and ThunderBolt. All SSDs have internal Garbage Collection, which is part of the drive firmware and OS independent. TRIM and Garbage Collection are not the same thing. If you have TRIM enabled, you're doing all you can to keep your SSD optimised.

Sorry but this is not correct.

You can issue a SATA Secure-Erase to the SSD (not to be confused with OS X secure erase, which just fills the drive with zeros and is VERY bad for SSD's!). This tells the SSD controller to issue an electrical pulse to all the memory cells, and which wipes ALL of the cells perfectly clean and returns it to a factory-fresh condition. This will return the performance to as-new.

It takes around 5 minutes to boot a linux CD, issue the command and wait for the cells to be wiped. From then on you can use CCC or similar to restore an OS X image to the SSD.

Whether it is worth doing this, is open to debate. But it does much more than TRIM ever can.
 
Sorry but this is not correct.

You can issue a SATA Secure-Erase to the SSD (not to be confused with OS X secure erase, which just fills the drive with zeros and is VERY bad for SSD's!). This tells the SSD controller to issue an electrical pulse to all the memory cells, and which wipes ALL of the cells perfectly clean and returns it to a factory-fresh condition. This will return the performance to as-new.

It takes around 5 minutes to boot a linux CD, issue the command and wait for the cells to be wiped. From then on you can use CCC or similar to restore an OS X image to the SSD.

Whether it is worth doing this, is open to debate. But it does much more than TRIM ever can.


Well ok, my post was accurate unless you want to back-up your drive, nuke it, and restore...

I'm assuming what you suggest would perform additional and, in day to day running, unnecessary writes to the cells?
 
Well, I wouldn't mind completely resetting the SSD and copying the whole backup to it again. I won't be doing this every month obviously, but it calms me to hear that it will be just as fast as it was on day one :p

So if someone should ever happen, I can quickly do a backup, clean the SSD, reinstall everything. For me that's really not an issue.

I'm just scared of the idea to buy something expensive, and then it's not as fast as it should be after a while anymore.
 
It takes around 5 minutes to boot a linux CD, issue the command and wait for the cells to be wiped. From then on you can use CCC or similar to restore an OS X image to the SSD.

From the Wikipedia entry for Secure Erase:

The ATA Secure Erase command is designed to remove all user data from a drive. With an SSD without integrated encryption, this command will put the drive back to its original out-of-box state. This will initially restore its performance to the highest possible level and the best (lowest number) possible write amplification, but as soon as the drive starts garbage collecting again the performance and write amplification will start returning to the former levels.

Sorry, but SATA Secure Erase is no substitute for TRIM.

Enabling TRIM is highly recommended for best performance.
 
From the Wikipedia entry for Secure Erase:



Sorry, but SATA Secure Erase is no substitute for TRIM.


Enabling TRIM is highly recommended for best performance.

No need to apologise!

And no-one said it was. It's something you can use if you want to completely wipe the drive. TRIM has its place of course (as I am constantly reminding people actually!)

----------

Well ok, my post was accurate unless you want to back-up your drive, nuke it, and restore...

I'm assuming what you suggest would perform additional and, in day to day running, unnecessary writes to the cells?

I am not sure that's true. It's not a write like any normal write. It's a reset. It might be nothing, or it could be worse than a normal write.

Assuming it's the equivalent of a normal write (in wear terms) then that's about 0.1% of the SSD's life used up, every time you do it. So you could do it once every 6 months for 5 years and lose 1% of the drives useful life. I don't really think that's a problem!
 
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I used parted magic from live cd:

I've tried to secure erase the ssd of my iMac late 2013 but to unlock the ssd (frozen) I have to send him (iMac) to sleep. After the I pushed a key to wake him up, and he does.

But the screen is still black. :rolleyes:

Any idea? thx in advance.
 
Not all do, but yes, most do. That is called over provisioning and it is space set aside so that when some of the NAND cells get worn out they are marked bad and replaced by a cell from the over provisioned area. So even as some of the cells wear out the SSD still has the same amount of usable space.

The idea of keeping some space free is more related to keeping speeds up. Personally, I think 10% or so free is plenty, but there is no hard rule here.

100% agree here.

Though, the OP says he wants to get an SSD in his next iMac. That sounds like he will buy it from Apple with an SSD in it already - not installing a third-party SSD. If it comes from Apple with an SSD, doesn't OS X provide the TRIM support by default? I just can't seem to remember...
 
I used parted magic from live cd:

I've tried to secure erase the ssd of my iMac late 2013 but to unlock the ssd (frozen) I have to send him (iMac) to sleep. After the I pushed a key to wake him up, and he does.

But the screen is still black. :rolleyes:

Any idea? thx in advance.

Strange one. What Mac do you have? I have tried this with a late 2012 iMac and it worked fine. The iMac went to sleep as you describe, but on wake up, the screen was back just fine and then I could wipe the SSD.

Have you tried it more than one time? If not, I would give it another go, just it case it was only a glitch.
 
Have you tried it more than one time? If not, I would give it another go, just it case it was only a glitch.
Yes, I have. ;)
It's the top model from late 2013, I guess there's a problem with the driver support and the nvidia graphics. Even the latest edition from parted magic doesn't handle it better.

I hoped somebody can give me a option command to get a better support for the graphics card or something like that. :eek:
 
100% agree here.

Though, the OP says he wants to get an SSD in his next iMac. That sounds like he will buy it from Apple with an SSD in it already - not installing a third-party SSD. If it comes from Apple with an SSD, doesn't OS X provide the TRIM support by default? I just can't seem to remember...

Yes... for sure. TRIM would be active by default with an Apple OEM flash storage device. Evens till keeping some free space is a good idea to keep speeds up. Allows for some swap space etc.
 
Yes... for sure. TRIM would be active by default with an Apple OEM flash storage device. Evens till keeping some free space is a good idea to keep speeds up. Allows for some swap space etc.

Thanks, that is what I had thought. I was thinking that some of the other comments in the thread encouraging the use of TRIM on the new machine could be counter-productive to use a third-party TRIM enabler on an Apple OEM SSD.
 
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Yes, I have. ;)
It's the top model from late 2013, I guess there's a problem with the driver support and the nvidia graphics. Even the latest edition from parted magic doesn't handle it better.

I hoped somebody can give me a option command to get a better support for the graphics card or something like that. :eek:

I guess you're right. I wonder if there is any other way to coax the graphics back into action though? There must be some linux utility to put the display to sleep... and wake it up again. Maybe running something like that might work? Other than that, I think you are right and you're going to need an updated nVidia driver.

Which Parted Magic image are you using? I have pmagic_2013_05_27.iso and this definitely works with a 2012 iMac. I could upload it somewhere if you want to try it?
 
Which Parted Magic image are you using? I have pmagic_2013_05_27.iso and this definitely works with a 2012 iMac. I could upload it somewhere if you want to try it?
Thanks for your support Chippy99 :)

I've tried 28_04_14 and 11_11_13, both showed the same issue. No problem on my retina MBP. :eek:
So I've tried another linux live CD which has nvidia drivers included (Kanotix) and it worked (wake after sleep).

So I have to work with the terminal solution from that live CD or have to include those drivers into the parted magic CD. :rolleyes:
 
Thanks for your support Chippy99 :)

I've tried 28_04_14 and 11_11_13, both showed the same issue. No problem on my retina MBP. :eek:
So I've tried another linux live CD which has nvidia drivers included (Kanotix) and it worked (wake after sleep).

So I have to work with the terminal solution from that live CD or have to include those drivers into the parted magic CD. :rolleyes:

... or run the Secure Erase utility from your Kanotix install (somehow???!?)
 
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