Defragging a SSD. Twice a year or never?

[Bent180]

Co-worker #1 is of the opinion you should defrag a SSD twice a year because there is a benefit.

Co-worker #2 is of the opinion you should never have to defrag a SSD because there is no benefit.



If any, which answer is correct? If both, or none, which method is more preferable?

 

[WyomingKnott]

There is no benefit to defragging an SSD, and a real cost.

Defragging on HDDs is done to put all of the sectors of any given large file together, reducing seek time when reading the file sequentially. On an SSD, this is meaningless because the "sector addresses" (not sure of the right term) used by the OS are mapped all over the place on the SSD by the optimization code. a) the defrag wouldn't make the actual data contiguous, and b) Even if it were, there is no benefit to physical contiguity on an SSD.

Plus, defragging will result in massive write-amplification and wear your SSD cells unneccessarily. I can't spell that word.

 

[ss202sl]

never.
http://forum.crucial.com/t5/Solid-State-Drives-SSD-Knowledge/Does-defragmenting-an-SSD-cause-any-long-term-performance-loss/ta-p/71051

 

[Fokissed]

WyomingKnott is right, there is no benefit at all. SSD's have a wear leveling algorithm that causes data to be spread all over the drive. This is transparent to the OS and doesn't affect performance. All defragging will do is a lot of writing and have no benefit, even if the OS "sees" the data as more contiguous after the defrag. SSD's actually benefit from having data spread between the cells, since the multi-channel controller can access more than one at a time.

 

[RetiredChief]

^ LOL, my spelling is a lot worst than yours.
You are correct. YOU DO NOT DEFRAG a SSD

HDD sector = 512 Bytes and typically the default size is 4K clusters. A cluster = 8 sectors. For a 20 Byte file, one cluster is used thus a waste of 4076 bytes since min size is 4K. Selecting a smaller Cluster size reduces the waste, BUT increases entries that must be written (thus read) in the file alloction table. PS the 512 Byte sector is probably a throwback to the 10Meg/20Meg MFM/RLL HDDs or even further back - LOL.

SSDs use a 4K pages (Cluster for HDD) plus arranged in Block size Which are typically 64 K (close analogy would be strip size in a raid0 configured HDD). Do no see a corralation for sector size.
Condensed explaination : http://www.gskill.com/products.php?index=469

 

[WyomingKnott]

Chief

Long time, no see.

 

[RetiredChief]

^ Been around, but they have increased my hours @ work. Started as "casual Time (upto 20 Hrs), then went to Part Time which was 20->30 hrs then to Full time (30Hrs).
Last year averaged about 35 Hrs. Have had a couple of weeks that were closer to 50 hrs. Good thing I enjoy what 'm doing, other wize I'd have to quit. The NICE thing about working when retired.

 

[ZippyPeanut]

Unless you change your settings, Windows 7 automatically defrags your hard drive once a week. If your C-drive containing your OS is an SSD, will Widows automatically defrag it?

 

[Fokissed]

Unless you change your settings, Windows 7 automatically defrags your hard drive once a week. If your C-drive containing your OS is an SSD, will Widows automatically defrag it?

In a few corner cases it may, but in many cases it won't. It seems to be able to detect it at the driver level and also uses WEI to detect it. (SSD seek times are orders of magnitude faster than HDD)

 

[RetiredChief]

Zippy, Wndows will disable defrag when windows is installed on an SSD. If migrating from HDD it is a GOOD idea to verify that it has been turned off.

 

[LiesaNotridge]

There is no benefit to defragging an SSD, and a real cost.

Defragging on HDDs is done to put all of the sectors of any given large file together, reducing seek time when reading the file sequentially. On an SSD, this is meaningless because the "sector addresses" (not sure of the right term) used by the OS are mapped all over the place on the SSD by the optimization code. a) the defrag wouldn't make the actual data contiguous, and b) Even if it were, there is no benefit to physical contiguity on an SSD.

Plus, defragging will result in massive write-amplification and wear your SSD cells unneccessarily. I can't spell that word.

Thank you for your answer. Actually, I also read about the similar opinions of drive defraging rate. It is really confusing. Thank you.