TRIM ?


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QazzaQY2K

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So whats this TRIM? Well I've sort of been on the hunt for an SSD (Solid State Disk) Got to know that many OS's see disks as normal HDD, optimal functions for normal "Mechanical" HDD's. Now I'm no Linux guru or anything. Is Ångström and also the version of XFce 4 compliant to use the internal nand-storage with TRIM functions?


If you want to read some more about it. Check out this wiki bellow.


http://en.wikipedia.org/wiki/TRIM_%28SSD_command%29
 
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Pandora doesn't have an SSD. It has a NAND flash chip. SSD is basically a hard drive, complete with it's own logic controller and a standard interface that has been used for years on computers; NAND flash in the Pandora is a persistent state similar to what's in SSDs, but it's more like xD or CF cards: direct access to the data bytes with no intelligence or controller, just raw power. Seems to me that TRIM is drive dependent, being a set of instructions that the drive itself will carry out rather than the OS. Furthermore, TRIM seems to only be beneficial in deletes, and 99.9% of the Pandora's NAND flash will never change, let alone be deleted under regular use.


So you're battling two things really: 1) the internal flash doesn't support TRIM; and 2) even if it did, you wouldn't see any benefit.
 
WizardStan said:
NAND flash in the Pandora is a persistent state similar to what's in SSDs, but it's more like xD or CF cards: direct access to the data bytes with no intelligence or controller, just raw power
Click to expand...

CF has logic, since a CF card is compatible with the ATA command set, and can be used as a IDE SSD with a passive adapter.
 
Pandora has a raw NAND device (MTD), on top of which we run the UBI wear leveling system, on top of which we run UBIFS (http://en.wikipedia.org/wiki/UBIFS).


And yeah, CF cards contain a FTL (flash translation layer) and an ATA compatible logic interface. I have one as my servers hd, and an another as my 486 laptops hd :p
 
slaeshjag said:
CF has logic, since a CF card is compatible with the ATA command set, and can be used as a IDE SSD with a passive adapter.
Click to expand...

urjaman said:
And yeah, CF cards contain a FTL (flash translation layer) and an ATA compatible logic interface. I have one as my servers hd, and an another as my 486 laptops hd :p
Click to expand...
Heh, whoops *blush*


Otherwise my point still stands I think: no logic controller, no TRIM, no point.
 
WizardStan said:
Furthermore, TRIM seems to only be beneficial in deletes, and 99.9% of the Pandora's NAND flash will never change, let alone be deleted under regular use.


So you're battling two things really: 1) the internal flash doesn't support TRIM; and 2) even if it did, you wouldn't see any benefit.
Click to expand...

Ah, no. TRIM is used in deletes to mark sections as used, so that when the OS writes, the hardware doesn't have to read what's already there, write an erase mask and then write your content. TRIM is a way to mark a section as completely ready to overwrite. I'm sure the wikipedia explains it better than me. :unsure: Suffice it to say that as unwritten blocks get used, SDD writes get slower because of the way flash works, unless TRIM is used.
 
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