Clean Install On 3rd Party SSD

Question

My brother has given me his 2010 MacBook Pro with a 256GB SSD running 10.9 and I want to do a clean install of OS X 10.10. Can this be done with a Bootable USB? I have read a few things about this called Trim and was wondering if I need to do something else? It is an aftermarket SSD (256GB OCZ Agility 3 SSD Drive) can I do a clean install straight away or do I need to do something else? Sorry for the newbie question and sorry if this has been asked, but I could not find an answer anywhere.

Answer 1

To create a bootable USB, you use Diskmaker X
<http://liondiskmaker.com>
TRIM is a nice addition, but not essential.  In Yosemite, the only way to enable TRIM for a 3rd party SSD, is to disable some Mac OS X security features.
<https://www.cindori.org/trim-enabler-and-yosemite/>
TRIM is a way for the file system to tell the SSD that a set of storage blocks were just deleted from a file, and the SSD is allowed to pre-erase them so they are ready to be re-used by the SSD.  And SSD cannot overwrite a block with data in it.  The SSD must perform a special kind of erase that when issued erases a much larger region of storage.  So the SSD, used a block remapping algorithm that takes a pre-erased block and write to that, then remaps that block so it looks like the block the file system asked to be written.  The file system thinks it has overwritten the block it specified, but in reality it wrote to a totally different physical block, and the SSD just makes it look like it.
To be able to do this the SSD needs a pool of pre-erased blocks, or it much find a region to erase, save any blocks in that region that have active data on them, then if necessary re-write blocks it could not find new home for, and write the data the file system wanted written.  This read, erase, write is more time consuming, so it pays for the SSD to have a pool of pre-erased blocks.  SSDs generally "Over Provisioned" so that they always have spares that file system does not know about.  Those over provisioned spares are also used to replace blocks and regions that have exceeded their write life (SSDs have a limited number of writes and then blocks and regions start to fail).
The SSD when idle will try to consolidate regions so it can have a pool of pre-erased blocks.  TRIM support just gives the SSD a larger pool so that if you are doing a huge write (copying some multi-gigabyte sized files disk to disk), the SSD will not easily drain its pool of pre-erased blocks.
But Mac OS X will still run faster with an SSD, even without TRIM, than it would on a rotating hard disk.  It will always read faster, and as long as you are not doing non-stop writes, the SSD will catch up and maintain a pool of pre-erased blocks for the next moderate write.
Some SSD vendors give more of the SSD to over provisioning, such as OWC where their SSD sizes are 240, 480, 960, instead of 256, 512, 1024, with the difference going to create a larger over provisioning pool so the SSD has more storage the file system does not know about to try and keep ahead of large write operations.