SSD defrag type software?

[Kotu]

To start out, I know a standard defrag is actually bad for a SSD since the data doesn't need to be stored in continuous blocks.

I do however think that something is missing, lets say you have an 80GB SSD with 70GB worth of games and the operating system. Up to ~50GB of that could be fixed data which never changes, the rest could be data which is patched fairly often or save games type areas as well as a heavily used pagefile/hibernate file (if you use hybrid sleep).

so half the SSD never changes from the first time its used, the rest (including the free space) takes a beating until it becomes un-writable.

So why isn't there any tools which "defrag" the SSD by moving all the fixed data off the unused portion of the SSD and moving all the heavily used files into the least used areas?

 

[Icm76]

SSD controllers dictate wear levelling, so I'm not sure how you could get around the controller? maybe you could ask this question to one of the manufacturers and see if there is a solution, or if the case is already considered and planned for in design of the controller.

 

[AbsenceJam]

Wear really isn't much of an issue.

 

[DragonQ]

So why isn't there any tools which "defrag" the SSD by moving all the fixed data off the unused portion of the SSD and moving all the heavily used files into the least used areas?

Because there is no need - SSDs, like USB flash drives, use wear levelling.

 

[Icm76]

read the OP again, a % of the drive is static data. All of that NAND gets written to once only (although it will be read many times) The remainder is variable data, and the wear levelling will make the best use of the variable portion.

After a long time the static portion of the NAND is in good condition, the variable part is heavily worn. How can the two portions be more evenly balanced?

 

[DragonQ]

read the OP again, a % of the drive is static data. All of that NAND gets written to once only (although it will be read many times) The remainder is variable data, and the wear levelling will make the best use of the variable portion.

After a long time the static portion of the NAND is in good condition, the variable part is heavily worn. How can the two portions be more evenly balanced?

Wear levelling would be pretty pointless if "static" data wasn't ever moved. See this:

The other type of wear leveling is called static wear leveling which also uses a map to link the LBA to physical memory addresses. Static wear leveling works the same as dynamic wear leveling except the static blocks that do not change are periodically moved so that these low usage cells are able to be used by other data. This rotational effect enables the SSD to operate until most of the blocks are near their end of life.

 

[Icm76]

Wear levelling would be pretty pointless if "static" data wasn't ever moved. See this:

That's the useful answer, thanks. So the problem the OP is concerned about shouldn't exist, although it would be nice to see confirmation from one of the manufacturers.

 

[Kotu]

I didn't realise there was already static wear leveling, any idea which (if any current) drives support it?

 

[Pilgrim57]

I didn't realise there was already static wear leveling, any idea which (if any current) drives support it?

As far as I'm aware OCZ only implement it on 120GB drives & above.

 

[DragonQ]

A quick search on their forums shows that their SandForce drives implement static wear-levelling as of late 2010 (or earlier). As long as you have the latest firmware you're fine.

 

[Icm76]

A quick search on their forums shows that their SandForce drives implement static wear-levelling as of late 2010 (or earlier). As long as you have the latest firmware you're fine.

Good work, give the man a coconut

 

[matty_1210]

diskeep will opimize an ssd