Two guys above have already pointed out issues with TRIM but I will reiterate; supporting such by Apple would be a waste of time. As has been already mentioned TRIM support in SSD is a stop gap measure. Instead people should be demanding that manufactures fix their SSD.
Dave
It's not as easy as that Dave, at least not without building in large amounts of redundant space on the SSD (which some manufacturers have done). Given that you'll still play close to $500 for 160GB, there is quite a serious trade off between performance and cost right now - paying for 40GBs that you'll never be able to use when it's $7 a GB is a big ask.
Saying TRIM is a waste of time might be easy for someone to say who hasn't invested in an SSD, but when your HDD performance drops by 60 or 70% after 3 weeks, you might change your mind - especially when the same doesn't happen on some 'other' OS.
To those that call TRIM a hack I have a question. How does a storage device or medium (of any kind) know the difference between a file you want to keep vs. one in your trash vs. a deleted file?
Call me crazy but I don't want my storage device to decide what is and isn't garbage.
It's not as easy as that Dave, at least not without building in large amounts of redundant space on the SSD (which some manufacturers have done). Given that you'll still play close to $500 for 160GB, there is quite a serious trade off between performance and cost right now - paying for 40GBs that you'll never be able to use when it's $7 a GB is a big ask.
160GB for $500? You definitely should not get SSDs at the apple store...
To those that call TRIM a hack I have a question. How does a storage device or medium (of any kind) know the difference between a file you want to keep vs. one in your trash vs. a deleted file?
You assume a drive needs to know this, when it doesn't. Quality SSDs are over-provisioned--they contain significantly more memory than is necessary to provide the external, advertised storage capacity. All the drive has to do is track which blocks are being used to support the advertised capacity. Unused blocks can be prepped in the background and utilized--quickly swapped into external view--to support fast write operations, which was historically the Achilles heel of SSDs.
Where are you finding current performance comparisons?
AnandTech has been detailing the latest SSDs in extensive articles for a couple years now. Truly a great resource. The Intel X-25 is still a great option for the price. While the new SandForce based drives are faster they are more expensive per GB.
The Intel X-25 is still a great option for the price.
Agreed.
Quote:
While the new SandForce based drives are faster they are more expensive per GB.
Unlike other controllers, the write performance of SandForce-based drives is very much dependent on the compressibility of the data. The extreme speeds advertised for these drives were obtained using highly compressible data.
You assume a drive needs to know this, when it doesn't. Quality SSDs are over-provisioned--they contain significantly more memory than is necessary to provide the external, advertised storage capacity. All the drive has to do is track which blocks are being used to support the advertised capacity. Unused blocks can be prepped in the background and utilized--quickly swapped into external view--to support fast write operations, which was historically the Achilles heel of SSDs.
That is not true. The auto garbage collection feature that's on some OCZ and Intel SSDs requires the drive to be formatted as NTFS (or possibly FAT). The firmware on the drive understands what the OS is doing, and when it sees a file deleted in the volume directory, it can reset the memory block.
The drive does not know what blocks are in use and what blocks aren't after they have been written to by the OS. When you delete a file, the OS simply removes its entry in the volume directory and that's it, the blocks used by the file aren't erased or reset. Without the drive understanding HFS, it hasn't a clue whether the file has been deleted or not. That whole idea of TRIM is once the file is deleted the OS can tell the drive which blocks can be reset, which means the SSD manufacturer doesn't have to write in support for every filesystem.
AnandTech has been detailing the latest SSDs in extensive articles for a couple years now. Truly a great resource. The Intel X-25 is still a great option for the price. While the new SandForce based drives are faster they are more expensive per GB.
Exactly, the Corsair I have is Sandforce based. The Intel SSDs are still excellent; light-years ahead of the 5400rpm drives that ship as standard with the MacBooks and noticably faster then anything Samsung based (i.e. the ones that come with the MBA and are on the Apple websites); they're just not the fastest anymore.
To those that call TRIM a hack I have a question. How does a storage device or medium (of any kind) know the difference between a file you want to keep vs. one in your trash vs. a deleted file?
For magnetic disk, it doesn't matter. For flash it's very important (as I will explain below)
Quote:
Call me crazy but I don't want my storage device to decide what is and isn't garbage.
Your not crazy, you probably just don't understand that flash is fundamentally different from magnetic disk. For flash drives, you absolutely want the drive to know what is fair game for deletion vs. what is valuable data and needs to be saved. The reason is the flash memory cells.
Flash memory cells have to be erased before they can be re-written to. And, relatively speaking, they are rather large. Also, writing to flash is slower than reading, and if you have to write to erase and then write to store the data, it's a double penalty. So, if you fill up all the empty memory cells on your SSD and go to write new data, the drive has to find a relatively empty cell, read the contents of it then write everything back. That's very slow.
TRIM let's the OS tell the drive specifically what is good and what is not (because when you delete a file, all the OS does is erase an entry in the file catalog/directory - that's why you can sometimes un-erase deleted files). The hard drive can, in idle time, re-arrange things so that it always has as many cells that are ready to write to ahead of time. It can do the read/erase/re-write shuffle when you aren't using the drive. This keeps performance high.
As someone else said, it's no fun using an SSD drive and then all the sudden have it perform worse than a floppy I had the first generation Intel in my work Windows laptop, and I hit the proverbial wall - the drive performance was so bad I went back to my old hard drive
The other way to go about it, as has been pointed out, is to have a set amount of reserve space that is hidden from the computer. The drive firmware uses that extra space to do the shuffle to ensure there are flash cells ready to be written to. The OWC Extreme SSD is the only example I know of this model, and I have one in my Mac Pro and it does work. I've been using it for months and no speed degradation - I'm very happy. I'm hoping if Apple does release TRIM support there might be a firmware update so I can get that extra space back, but if not oh well - it's a nice OS agnostic drive that will work with any device - not just computers.
For magnetic disk, it doesn't matter. For flash it's very important (as I will explain below)
I do understand what TRIM is and does. I do understand magnetic media does not suffer from writing over a block and why. The threads above mine described garbage collection in terms that sounded like the SSD just "knows" what the user and file system have discarded. That doesn't happen with HFS. My query was to ask them to think through how the SSD "knows". I don't want an SSD that has to have firmware revs every time an vendor revs/fixes the file system software.
Reserve space is a nice temp fix because it'll be used as an alternative to writing over a used block. The SSD will eventually run out of that too.
I'm surprised Apple don't have Flash as drive-caches in all their mobile products. With all but heavy file-writing using only a few GBs I'd have though including 8 or 16GB flash as standard would have brought worthwhile performance & battery-life advantages.
Maybe the addition of TRIM support is a sign they're gearing up?
Comments
Two guys above have already pointed out issues with TRIM but I will reiterate; supporting such by Apple would be a waste of time. As has been already mentioned TRIM support in SSD is a stop gap measure. Instead people should be demanding that manufactures fix their SSD.
Dave
It's not as easy as that Dave, at least not without building in large amounts of redundant space on the SSD (which some manufacturers have done). Given that you'll still play close to $500 for 160GB, there is quite a serious trade off between performance and cost right now - paying for 40GBs that you'll never be able to use when it's $7 a GB is a big ask.
Saying TRIM is a waste of time might be easy for someone to say who hasn't invested in an SSD, but when your HDD performance drops by 60 or 70% after 3 weeks, you might change your mind - especially when the same doesn't happen on some 'other' OS.
Call me crazy but I don't want my storage device to decide what is and isn't garbage.
It's not as easy as that Dave, at least not without building in large amounts of redundant space on the SSD (which some manufacturers have done). Given that you'll still play close to $500 for 160GB, there is quite a serious trade off between performance and cost right now - paying for 40GBs that you'll never be able to use when it's $7 a GB is a big ask.
160GB for $500?
160GB for $500?
As an example - Newegg.com has the Intel X25-M 160GB for $449.00. Apple doesn't sell a decent 160GB.
As an example - Newegg.com has the Intel X25-M 160GB for $449.00. Apple doesn't sell a decent 160GB.
I just went with the 80GB Intel X-25 G2. I'm using 25GB. I moved my User folder to my internal 500GB HDD using these simple option:I'll be installing the 1TB 2.5" HDD (which does fit) as soon as I get word that the driver incompatibility issue has been resolved.
160GB for $500?
As an example - Newegg.com has the Intel X25-M 160GB for $449.00. Apple doesn't sell a decent 160GB.
$449 is "close to $500" and the X25-M is very middle of the road now performance wise anyway, so I am not sure why I got picked up for that.
You can get crappy SSDs for less, but that defeats the object really.
To those that call TRIM a hack I have a question. How does a storage device or medium (of any kind) know the difference between a file you want to keep vs. one in your trash vs. a deleted file?
You assume a drive needs to know this, when it doesn't. Quality SSDs are over-provisioned--they contain significantly more memory than is necessary to provide the external, advertised storage capacity. All the drive has to do is track which blocks are being used to support the advertised capacity. Unused blocks can be prepped in the background and utilized--quickly swapped into external view--to support fast write operations, which was historically the Achilles heel of SSDs.
$449 is "close to $500" and the X25-M is very middle of the road now performance wise anyway, so I am not sure why I got picked up for that.
You can get crappy SSDs for less, but that defeats the object really.
Where are you finding current performance comparisons?
Where are you finding current performance comparisons?
AnandTech has been detailing the latest SSDs in extensive articles for a couple years now. Truly a great resource. The Intel X-25 is still a great option for the price. While the new SandForce based drives are faster they are more expensive per GB.
The Intel X-25 is still a great option for the price.
Agreed.
While the new SandForce based drives are faster they are more expensive per GB.
Unlike other controllers, the write performance of SandForce-based drives is very much dependent on the compressibility of the data. The extreme speeds advertised for these drives were obtained using highly compressible data.
You assume a drive needs to know this, when it doesn't. Quality SSDs are over-provisioned--they contain significantly more memory than is necessary to provide the external, advertised storage capacity. All the drive has to do is track which blocks are being used to support the advertised capacity. Unused blocks can be prepped in the background and utilized--quickly swapped into external view--to support fast write operations, which was historically the Achilles heel of SSDs.
That is not true. The auto garbage collection feature that's on some OCZ and Intel SSDs requires the drive to be formatted as NTFS (or possibly FAT). The firmware on the drive understands what the OS is doing, and when it sees a file deleted in the volume directory, it can reset the memory block.
The drive does not know what blocks are in use and what blocks aren't after they have been written to by the OS. When you delete a file, the OS simply removes its entry in the volume directory and that's it, the blocks used by the file aren't erased or reset. Without the drive understanding HFS, it hasn't a clue whether the file has been deleted or not. That whole idea of TRIM is once the file is deleted the OS can tell the drive which blocks can be reset, which means the SSD manufacturer doesn't have to write in support for every filesystem.
AnandTech has been detailing the latest SSDs in extensive articles for a couple years now. Truly a great resource. The Intel X-25 is still a great option for the price. While the new SandForce based drives are faster they are more expensive per GB.
Exactly, the Corsair I have is Sandforce based. The Intel SSDs are still excellent; light-years ahead of the 5400rpm drives that ship as standard with the MacBooks and noticably faster then anything Samsung based (i.e. the ones that come with the MBA and are on the Apple websites); they're just not the fastest anymore.
As of the last MBP update the largest drive Apple offers for their notebooks are SSDs by 512GB.
Just a typo I'm sure but since it is significant (changed to 512GB in above quote instead of 12GB).
Just a typo I'm sure but since it is significant (changed to 512GB in above quote instead of 12GB).
Fixed. Thanks.
To those that call TRIM a hack I have a question. How does a storage device or medium (of any kind) know the difference between a file you want to keep vs. one in your trash vs. a deleted file?
For magnetic disk, it doesn't matter. For flash it's very important (as I will explain below)
Call me crazy but I don't want my storage device to decide what is and isn't garbage.
Your not crazy, you probably just don't understand that flash is fundamentally different from magnetic disk. For flash drives, you absolutely want the drive to know what is fair game for deletion vs. what is valuable data and needs to be saved. The reason is the flash memory cells.
Flash memory cells have to be erased before they can be re-written to. And, relatively speaking, they are rather large. Also, writing to flash is slower than reading, and if you have to write to erase and then write to store the data, it's a double penalty. So, if you fill up all the empty memory cells on your SSD and go to write new data, the drive has to find a relatively empty cell, read the contents of it then write everything back. That's very slow.
TRIM let's the OS tell the drive specifically what is good and what is not (because when you delete a file, all the OS does is erase an entry in the file catalog/directory - that's why you can sometimes un-erase deleted files). The hard drive can, in idle time, re-arrange things so that it always has as many cells that are ready to write to ahead of time. It can do the read/erase/re-write shuffle when you aren't using the drive. This keeps performance high.
As someone else said, it's no fun using an SSD drive and then all the sudden have it perform worse than a floppy
The other way to go about it, as has been pointed out, is to have a set amount of reserve space that is hidden from the computer. The drive firmware uses that extra space to do the shuffle to ensure there are flash cells ready to be written to. The OWC Extreme SSD is the only example I know of this model, and I have one in my Mac Pro and it does work. I've been using it for months and no speed degradation - I'm very happy. I'm hoping if Apple does release TRIM support there might be a firmware update so I can get that extra space back, but if not oh well - it's a nice OS agnostic drive that will work with any device - not just computers.
It just displayed the information reported by the SSD.
That's why the person gets the "No" from his Intel SSD now because he upgraded to the "HD" firmware, which started supporting TRIM.
For magnetic disk, it doesn't matter. For flash it's very important (as I will explain below)
I do understand what TRIM is and does. I do understand magnetic media does not suffer from writing over a block and why. The threads above mine described garbage collection in terms that sounded like the SSD just "knows" what the user and file system have discarded. That doesn't happen with HFS. My query was to ask them to think through how the SSD "knows". I don't want an SSD that has to have firmware revs every time an vendor revs/fixes the file system software.
Reserve space is a nice temp fix because it'll be used as an alternative to writing over a used block. The SSD will eventually run out of that too.
Maybe the addition of TRIM support is a sign they're gearing up?
McD
I'll be installing the 1TB 2.5" HDD (which does fit) as soon as I get word that the driver incompatibility issue has been resolved.
What is this incompatibility you speak of??
Working fine here (2x1tb WD drives in a macbook unibody
God do none of you appleinsiders look up facts before stating complete nonsense. TRIM is a hack? TRIM isn't standard? TRIM is software? lol. WTF!?!
Well then oh wise one tell us clueless "insiders" the truth.
Otherwise your post is nothing but trolling.