SSD Help

[mo2580]

hi everyone,

i just want to know what trim is really about?

alot of people say only use ssd's with win 7 because of trim support and it felt at the time that the trim was some sort of advance wear levelling but now i have read about it looks as if its some sort of advance garbage collection.

so which one is it?

[benzeman]

It makes the SSD wear out more evenly, as with a normal HDD if you don't use all it's capacity then your writes will all be near the start. With an SSD, if it's half-full, you can double it's lifespan by distributing your writes across the disk.

[Tolmandary]

Basically the disk manages how each individual cluster of data is used so they all get used evenly. With magnetic drives the data is written sequentially onto the drive so clusters nearer the start of the drive get used first and the only time those near the end will get used is if the drive is almost full or very badly fragmented. Because SSD's have far fewer read/write actions before a given cluster fails their lifespan can be considerably expanded by ensuring that all clusters are used at approximately the same rate as each other, also writing or reading data from any given SSD cluster takes the same time, whereas for magnetic drives the clusters inside the ring are faster to access and of course to reach the edge the read/write tips have to be physically moved outwards.

[mo2580]

so is it safe to say that it is some sort of advance wear levelling system?

Also do you know if the ssd drives have built in wear levelling similar to usb flash drives that have the FTL flash translation layer?

thanks

[benzeman]

I have yet to see an SSD that doesn't support TRIM. You'll need windows 7 and supporting drivers though!

[Tolmandary]

Be aware though that again TRIM doesn't work for SSD's in RAID arrays.

[mo2580]

does anyone know if ssd drives actually have some sort of wear levelling in built?

[Bezza]

Be aware though that again TRIM doesn't work for SSD's in RAID arrays.

Am I to assume it's not a good idea to put SSDs in RAID arrays then? I was going to on my new build, for no reason other than I can so why not, but if that's a bad idea on account of not being able use TRIM, I'll have to have a rethink (and also wish I had bought the 512GB version istead of 2 x 256GB )