Ssd full format vs quick

[SirThomas]

Quite simply with all the complicating information on how you should maintain SSD'd i was simply wondering how one formats the things?

Is a quick format the best bet, or maybe a full zero filling...

I'll leave it to you chaps to inform me

Tom

 

[SirThomas]

EDIT: One more thing... anyone simply explain to me what the devil this drive alignment stuff is all about? It's certainly got me vexed

 

[sminlal]

IMHO a quick format is best for an SSD.

The issue with alignment is that XP doesn't align disk partitions on the same sized boundary as is used in the flash memory blocks. It's not an issue for hard drives, but it means that a lot of SSD I/O needs to to physically access two blocks of flash memory instead of just one.

 

[amnotanoobie]

Based on the old HDD format methods, the Full Zero Filling or Full Format would go through each and every byte on the drive and set it to zero. With Quick Format, all it does is remove the pointers and declare the space used as free space.

Full format is usually only required when you want data security (no one else tries to recover your old files) or checking for bad sectors (which shouldn't be a problem of an SSD). It wouldn't be advisable to full format an SSD as it introduces additional unnecessary wear, unless privacy is a concern.


Don't know about the drive alignment though....

 

[SirThomas]

Well, ta muchly chaps, most helpful

Looks like a simple quick format then... praise be to Win7!
(although I DO like the option of Full or Quick formats nevertheless

 

[sub mesa]

A Full Format does NOT zero-write the entire partition!

It does exactly the same as the Quick format: zero-writing the first 20MB and i recall some space at the end, and writing new filesystem information afterwards. The Full Format will read every sector on the partition for clues of any bad sectors, so it knows this and can store them in a file $BadSect in the root of the drive. It does NOT zero-write all data.

So a full format is only for detecting bad sectors, SSDs dont have those so no reason (but also no harm) to do a full format.

 

[sminlal]

Of course we're kind of guessing when it comes to the operation of the Windows 7 format utility. If it really is optimized for SSDs then a "full format" might simply issue a TRIM command for the entire disk. That wouldn't be a bad thing.

It would be nice to see a paper describing what ALL of the Win7 SSD optimizations are.

 

[sub mesa]

You're right i have no way if this still holds true for Windows 7. But somehow i doubt they did what you suggested.

But actually this is unnecessary, just one command to the SSD will wipe all the mapping clusters that keep track of where data is actually being stored versus the mapped LBA cluster. Due to the SSD moving data this dataset can grow large whenever you're writing data non-sequentially. A simple 'master wipe' command can simply delete all mappings and the drive is at its factory performance level.

Also see:
http://www.pcper.com/article.php?aid=669&type=expert&pid=6

 

[RetiredChief]

Windows 7 will map the partitions correctly Think vista will also BUT not positive.. I forget the method but this can be verified. Put an SSD in laptop with win 7 and verified the partition mapping. As stated by another - only a problem with XP

http://thunk.org/tytso/blog/2009/02/20/aligning-filesystems-to-an-ssds-erase-block-size/

Added:
Use Diskpar.exe with "-i A " first get Diskpar.exe and put in root directory od C: (Boot drive)
open a dos cmd wind (W/Run as Admin). change directory to Root and Enter "Diskpar -1 A"
it will provide info, just divide "startingOffset by Sector size. Should be a whole Nr.

 

[sub mesa]

XP puts the partition at 31.5KiB
Vista/Win7 puts the partition at 1024KiB or 1MiB.

This is not yet perfect since with flash cell blocks of 640KiB you still have a (minor) misalignment. Also RAID5's can have a misalignment with this 1MiB offset, for example a 4-disk RAID5 with 128KiB stripesize will have a full stripe block of (4-1) * 128KiB = 384KiB, which is still a misalignment with 1024KiB offset.

But the issue is either resolved or less severe now, so Vista/Win7 is an improvement in this regard.

 

[SirThomas]

Lo there chaps, seeing as I didnt get round to reinstalling/formatting last night I thought id do it now... but oddly enough HDDErase (which now seems the best bet) (thanks sub_mesa) does'nt seem to want to do anything once started up... just stays on one screen forever.

Just wondering of anyone had used it before?

Tom

 

[sub mesa]

Checkout the link posted above (or here: http://www.pcper.com/article.php?aid=669&type=expert&pid=6)

It lists what the reviewer used and did to wipe the Intel X25-M. Especially, the older version does not work. The page lists a download link to a version below which does work with the X25-M.

Hope this is of help.

Note just in case: by using HDDErase it does exactly that: wipe all data; or actually the special mapping areas (HPA) that keep track of where data is actually being stored on the SSD. With this information wiped, the drive is like as it left the factory, just with some random data on the surface but with 100% performance level.

Using the new firmware available for X25-M, the issue of degrading performance is pretty much fixed. So usage of HDDErase is not really required, though it can be useful and the suggestion of windows using it whenever formatting a disk is a good one, because that would also reset the drive's performance level to factory conditions.