Defrag SSD ever ?

So you don't like the *occasional* defrag for ntfs, but you are ok with the sort of wear introduced by frequent wipe and full data restoration? Because you think the controller should be left to manage the drive, you wipe every time a benchmark shows a dip?

Lots of SSDs are a con anyway, like when all the sandforce drives quoted compressed data speeds, and when drives use empty space to improve speeds and drop off when less that half empty, a defrag here and there is the least of people worries (840 etc).
 
Ricimer said:
So you don't like the *occasional* defrag for ntfs, but you are ok with the sort of wear introduced by frequent wipe and full data restoration? Because you think the controller should be left to manage the drive, you wipe every time a benchmark shows a dip?

Lots of SSDs are a con anyway, like when all the sandforce drives quoted compressed data speeds, and when drives use empty space to improve speeds and drop off when less that half empty, a defrag here and there is the least of people worries (840 etc).
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I didnt say that, I said after I secure erased and restored I notice a slight dip in the reads and writes if I benchmark, but then a few weeks later the reads/writes are back where they should be,, so there's no point in defragging a SSD, because all your doing is your destroying writes to the memory cells, as each cell has a limit of writes let's say 10,000,000, then the cell(s) becomes read only. Id hate to think how much writing defragging does, as its all over the drive taking bits from here and there, plus moving chunks too:eek:. You say you only defrag occasionally, well thats the worst as I guessing everytime you defrag, you data is fragmented all over the drive, so a awful lot of writing will be needed to sort it out. and for what?

Ah Yeah I only restore my SSD when I or windows messes up and that is only 1 write to each cell that I have data on, not multiple writing to a cell that defragging does.
 
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How do you actually know data is being moved when a defrag is done, it may just be possible the drive controller is just 'reindexing' the data so it looks like it has moved.
 
Reading a fragmented file from an SSD won't be any slower then reading a contiguous file from an SSD. In theory, it could even be slower if you end up reading from one chip rather than several and end up using all the bandwidth to that chip (SSDs rely on parallelisation for their speed - hence when a 128GB SSD has half the memory chips of the 256GB version, it is often slower too).

You are also not going to be physically able to defrag an SSD. As some others have said, where Windows "thinks" data is stored on an SSD and where it's actually stored is different due to SSD firmware chips using wear levelling to avoid overusing the same writable block.

Let's say Windows tells the SSD to store this file in blocks 1-5 and blocks 10-15. The SSD says no problem. The SSD actually knows blocks 1-5 and 10-15 have been used a few times before, so stores these in blocks that haven't been used so much - say blocks 50,1000,1020,1031,1050,1060,2000,2007,2050,2100. Next time Windows asks for the file in blocks 1-5 and 10-15, the SSD knows to actually retrieve this file from 50,1000,1020,1031,1050,1060,2000,2007,2050,2100. This internal organisation on the SSD is completely invisible to Windows, hence a program in Windows will see blocks 1-5 and 10-15 used where actually the file is elsewhere. If you then run a defrag program in Windows, the defrag program will say to the SSD to move the data in 10-15 into blocks 6-10 to make a contiguous file but the SSD may well move these into blocks in the 3000 range (because the wear levelling says these haven't been used much). Result is a happy defrag program, but the files on the SSD are actually still spread all over the drive and all the program has done is move them within the drive for no benefit.

TL;DR - Don't waste your time trying to defrag an SSD - it simply doesn't work.
 
Ricimer said:
Moving a few GB every now and then is not going to make much difference. And it will be very slightly faster as there are less file system calls to retrieve a contiguous file. It's not pointless, it reduces fragmentation, even if it is a low latency device.
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It is pointless, because the net benefit will be bugger-all.
 
lude1962 said:
How do you actually know data is being moved when a defrag is done, it may just be possible the drive controller is just 'reindexing' the data so it looks like it has moved.
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You can tell something going on pretty serious as normal hdds work dam hard when defragging.
 
all manufacturers say no, so its NO and the main reason is that defragging uses too much writing to memory cells. So untill memory cells can stand infinite number of writes like RAM can, its no till then.
 
I had a thought how you could defrag a ssd without causing too meny writes, Would this work..........?
Copy SSD partitions onto a HDD using imaging software and defrag the HDD instead of SSD. Then restore the HDD partitions back onto the SSD, secure erasing the SSD first though.
 
Phil2008 said:
I had a thought how you could defrag a ssd without causing too meny writes, Would this work..........?
Copy SSD partitions onto a HDD using imaging software and defrag the HDD instead of SSD. Then restore the HDD partitions back onto the SSD, secure erasing the SSD first though.
Click to expand...

Won't work. The wear levelling techniques on the SSD will mean the data is not written into the blocks you are asking it to be written into (as I detailed above). Your technique will work on a brand new SSD that has had no blocks written to, but on a drive that has had any use (even after a secure erase), it won't.
 
Confused Stu said:
Won't work. The wear levelling techniques on the SSD will mean the data is not written into the blocks you are asking it to be written into (as I detailed above). Your technique will work on a brand new SSD that has had no blocks written to, but on a drive that has had any use (even after a secure erase), it won't.
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Thanks,, so a word doc of a file of somekind could still be broken up, or fragmented even though the defrag software says no files fragmented?

Edit: well I guess thats how they work, dotting the data in random places on the SSD, so the cells wear equally
 
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