Ocz Gc

Hrm well on OCZ's website they have a rar'd exe for a GC program, but I thought with TRIM it automatically does it. Why would OCZ release a seperate program, it doesn't trust Windows to do it properly?

 

Could it perhaps work on RAIDed drives where TRIM doesn't? Or maybe for OSes that don't support TRIM, like XP?

 

When you delete a file, the blocks of storage on the disk aren't actually erased - they are simply marked as "available" so that they can be overwritten with new data. On a mechanical hard drive, the overwrite isn't an issue. With an SSD, you can't easily "overwrite"... the storage block needs to be erased first, before new data can be written.

Traditional SSD's would clear the storage blocks at the time that they are needed (when you attempt to copy/write a file). This adds a lot of overhead, and would make file copies / writes much slower overall as the SSD became heavily used. The much more efficient way to handle this would be to clear blocks before they are actually used, so that the file copy / write can happen at full speed.

TRIM and OCZ_GC (garbage collection utility) effectively do the same thing - they clean up the data from storage blocks on the SSD that have been marked as "deleted". TRIM does this at the moment the file is deleted, and clears up the blocks used by the deleted file. Garbage Collection does this in bulk across the entire drive as a one-time pass whenever you run the utility.

GC is useful when TRIM is not available, like older OS'es (WinXP) and RAID arrays. More recent firmware revisions of OCZ drives (firmware v1.41 and above, I believe) support the use of OCZ_GC for drives in a RAID array, which is a configuration that TRIM does not support.

 

TRIM does not do this 'at the moment the file is deleted'.

It simply lets the drive know that it can do it at any time from then.

Whether it does and how fast it does it is another story and is mostly dependant on how aggressively GC is implemented on that particular SSD/Controller/Firmware.

This is the SSD with the most aggressive GC now available:

See:
Kingston SSDNow V+100 Review - AnandTech :: Your Source for Hardware Analysis and News

 

Hrm that's a good point, I forgot XP doesn't support TRIM. But why on earth would you install XP on an SSD lol

Wonder if they have that for OS X cause no Apple OS supports TRIM. And I don't think people are going to wait for 10.7 for TRIM

 

Well as long as there's decent GC, TRIM isn't entirely necessary. Samsung drives are supposed to have efficient GC as well.

 

I'm assuming that's off the controller? Why wouldn't certain high end SSD controllers (for which money doesn't matter) have good GC as that extends the life of the SSD?

 

GC is subpar compared to a properly working implementation of TRIM. (Where TRIM is supported of course, not talking about RAID here).

It wastes write cycles needlessly, it wastes power needlessly and it increased the write factor amplification of the SSD in question.

 

OCZ_GC only works for Indilinx-based SSDs, doesn't it?

 

I don't think so, it listed the Agility 2 on it, which has SF-1200 controller.

 

Strange.

As far as I know, there is no such tool for any Sandforce based SSD. In fact, no one can effectively do anything to a Sandforce other than SE.

TRIM is supposed to be honoured but doesn't restore(well at least not immediately) any performance. You can only allow the computer to sit idle and HOPE it can do the GC.

 

That's what I thought. So, I checked the OCZ site again.

OCZ_GC is not for SF based SSDs.

 

Yeah I just double checked it. I posted that real late and I musta saw Agility and Solid 2 combined into Agility 2. >__<