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Silverstring

macrumors 6502
Original poster
Apr 30, 2005
485
830
I am a frequent user of both DiskWarrior and Drive Genius. I'll run things like defrag (Drive Genius) or rebuild volume directory (DiskWarrior), on average about once a month, to keeps things running smoothly.

I have no experience with SSDs, but have one on the way, so I apologize if this seems like a silly question.

With the things that SSDs do in the background, like overprovisioning and garbage collection, do these types of old school disk utilities still have the same benefits? Can they actually cause harm? Or are they simply not needed?

Any info is appreciated.

Note: I posted this in the MBP forum not only because that's where my SSD is going, but also because this seems to be where the majority of SSD discussion is taking place.
 
Keep your SSD away from any defrag software. It will cause unnecessary use of memory cells. DiskWarrior will probably not be able to recover files if TRIM is used.
 
Correct me if I'm wrong but I think defragmentation is only necessary on traditional drives because they work something like a phonograph, with a little detector that can only read what's directly under it. Efficiently organizing the data makes it easier for the computer to physically direct the appropriate piece of the magnetic disc underneath the detector, especially in cases where one file is stored in two chunks on different hemispheres of the drive.

A Solid State Drive is more like random access memory in that everything's stored on a chip to be pulled out electricly on demand. There's no detector to be closer or farther away from, so all the data's gathered at once and everything's happy.

Solid State Drives do have their own organizational problems but it's moreso a manner of confusion than workload. Because files aren't fully erased when you delete them, the O.S. might tell the SSD to write over a block that's empty when the SSD's controller still sees your deleted file and skips over it. TRIM is intended to bring the O.S. and the SSD back into a degree of agreement but it's a completely automated process so you never have to worry about actively running a tool to do so. You just have to make sure both the O.S. and the SSD are TRIM enalbled.

As par disc recovery, I dunno about that quite so much. I've heard it's a bit of a security concern that it's easier for somebody to actually hack into the drive and read the NAND flash with physical tools directly, because secure erase commands don't typically work because the OS and SSD don't see 1-1, meaning somebody can find something when the SSD is told to erase something but misses the mark. I dunno about data recovery software but I'd guess it'd have to be specially designed for use with a SSD for similar reasons...
 
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I've never used any type of defrag on any of my SSDs, even the original 64GB one, and all still run perfectly. I've never used TRIM until a few weeks ago. The only thing I've ever used was Onyx to clean cache and cookies.
 
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