what is the difference between a full and quick format?

[Special K]

When would I want to use one instead of the other?

 

[Rapidskies]

I believe a quick format changes just the header of the drive/floppy, while a full actually writes to each sector.

 

[Haden]

Full format scans for bad sectors, quick does not.
You should do quick always, unless you suspect media might be defected or have some time to spare.

 

[alkemyst]

quick just clears the master boot record, all the data is still there. A real format clears the data somewhat (I believe some have said it's possible to retreive, however I don't see how at any non extremely expensive level) and has options for checking for bad sectors, etc.

 

[BlackMountainCow]

Generally speaking full format (format c: ) is better but slower. If u wanna make sure that your data can't be restored add the option /u (format c: /u) to it for (unrecoverable). For a quick format take /q (format c: /q) which is usually good enough for floppys or CD RWs if u plan to write new data on it right after. So it's mainly about your security. But for example if u make a clean OS install I always take the full with /u to make sure the old OS is wiped out!

@ alkemyst: yeah, it's still retreivable but only in a clean room with magnetic sensors that'll scan the harddrive and somehow find the remains of the magnetized particles on the hd and recover at least some of the info by reading those traces. but it costs u something like a small car.

 

[Nothinman]

A real format clears the data somewhat (I believe some have said it's possible to retreive, however I don't see how at any non extremely expensive level) and has options for checking for bad sectors, etc.

A full format only checks for bad sectors, it doesn't clear the sectors.

Generally speaking full format (format c: ) is better but slower.

No it's not, it's just slower. Unless you suspect the drive is dying or has bad sectors there's no reason to do a full format.

 

[Haden]

It's low-level format which whipes all data out and stuff, not full.
You can do very old trick : run format c: then abort it at <99% - nothing will happen to your data, nothing because nothing was done, only non-destructive scan for bad sectors (unless for some reason formating is done before scanning for bads now, which is probably not).

 

[Sunner]

Also, neither a quick nor full clears the MBR.

The MBR is separate from the partitions.

 

[alkemyst]

I meant the drive table was reset that shows the links of all the files and sectors.

There are options for a full format that does ruin the data.

 

[Soybomb]

There are options for a full format that does ruin the data.

If you want to destroy the data on the drive you need to write over the entire disk (low level format, not the usual dos format utility). This will be a time consuming task. Ideally you will write garbage to the disk multiple times to lessen the chances of recovery.

 

[Nothinman]

I meant the drive table was reset that shows the links of all the files and sectors.

Which is very different from clearing the MBR.

There are options for a full format that does ruin the data.

Not with Microsoft's version of format.

 

[Gage8]

Originally posted by: Haden
It's low-level format which whipes all data out and stuff, not full.
You can do very old trick : run format c: then abort it at <99% - nothing will happen to your data, nothing because nothing was done, only non-destructive scan for bad sectors (unless for some reason formating is done before scanning for bads now, which is probably not).

no it's not a low level format. a low level format is writing your drive full of 1's and 0's. WD, IBM, ect each have a program that does a low level format. You have to download it from their site. Otherwise your data is still there.

 

[Nothinman]

no it's not a low level format. a low level format is writing your drive full of 1's and 0's. WD, IBM, ect each have a program that does a low level format. You have to download it from their site. Otherwise your data is still there.

If you want to get really technical a true low level format isn't possible, it's done once at the factory to align the heads, set the physical sector size, etc and it can't be done again without damaging the drive.