does OSX treat SSD hardware in such a way that TRIM isn't required? - Hardware & Software

i noticed that OSX is very good at keeping fragmentation to a minimum and i was wondering if apple did the same thing for SSD's? after seeing the graphics power of a macbook air I am thinking about picking one up but this may be a deal breaker (I'm already on the edge as it is)

[QUOTE=meppers;25691225]after seeing the graphics power of a macbook air I am thinking about picking one [/QUOTE] Why? Is this because of the size? Also, I believe autodefrag is enabled too.

I'd say just get a regular MacBook. The air is a little silly. Unless you are clumsy or always on the go, in which case you will benefit from the aluminum and lightness, respectively.

well I can't really describe it but I have issues with my back and I can't carry heavy things in my backpack or else i get serious fatigue and back pain. I can't carry my schoolbooks with me because it hurts so bad so i need a lightweight laptop and I prefer apple laptops, but the 4.5 pound MacBook pro is just too heavy (went to a doctor, he said I have a mild humpback, fucking hereditary shit)

[QUOTE=meppers;25691225]i noticed that OSX is very good at keeping fragmentation to a minimum and i was wondering if apple did the same thing for SSD's? after seeing the graphics power of a macbook air I am thinking about picking one up but this may be a deal breaker (I'm already on the edge as it is)[/QUOTE] You don't seem to understand why TRIM is required. Here's a brief overview: When you write data to a hard disk, it writes the bits directly. When you delete something, it deletes the reference to the data but doesn't erase the data (this is why un-delete software is possible without forensic equipment). Solid-state disks operate differently than hard disks. When an HDD writes something, it just does: it writes the bytes to the disk and that's that (simplification... there is other crap written for error correction, metadata, etc). SSDs do not write the bytes directly, however: they have 1, 0 and "unset" values that each bit on the disk can hold. Before an SSD can write something, it needs to make the bit "unset" then "set" it to 0 or 1 as required. This is slower than writing directly to an already "unset" bit. TRIM tells the disk what bits can be "unset" when a file is deleted from the filesystem. When the OS sends TRIM the SSD removes the reference then on its own time it will "unset" the bits so when it needs to write there later, it can do so immediately. This makes it snappier when writing. If the OS doesn't send the TRIM command or another software daemon constantly finding and reporting them to the SSD it will encounter the "unset" problem a lot. If the OS doesn't have TRIM, the SSD's writes get slow. So, no, just using OSX won't improve SSD performance.

and i assume there are no 3rd party TRIM applications :smith:

[QUOTE=meppers;25702211]well I can't really describe it but I have issues with my back and I can't carry heavy things in my backpack or else i get serious fatigue and back pain. I can't carry my schoolbooks with me because it hurts so bad so i need a lightweight laptop and I prefer apple laptops, but the 4.5 pound MacBook pro is just too heavy (went to a doctor, he said I have a mild humpback, fucking hereditary shit)[/QUOTE] Oh my gosh, my mom has the same kind of problem. Have a heart.

[QUOTE=meppers;25711978]and i assume there are no 3rd party TRIM applications :smith:[/QUOTE] TRIM support is needed inside the code that communicates with the disk on behalf of the filesystem.... So probably not.

so once every single bit in an SDD becomes either a 1 or a 0 how slow would the drive become?

could I boot linux from a flash drive and run a TRIM command from that?

No you cannot boot linux from a flash drive. At least, not by default. I have tried. There might be some third party software that lets you, though.

[QUOTE=MacTrekkie;25780421]No you cannot boot linux from a flash drive. At least, not by default. I have tried. There might be some third party software that lets you, though.[/QUOTE] If you don't want to use a program like UNetBootIn, just extract the ISO, copy it to the flash drive, and write the bootloader that comes with the ISO to the boot sector of the flash drive (with the standard CLI utility dd).

But you cannot boot from it. As in, you cannot connect the flash drive and choose it as a valid boot drive. I did use UNetBootIn to install Linux Mint to a flash drive and it will not be available either from Startup Disk system options or when you hold down option as the computer is booting.

Oh, if you're talking about actually booting it from mac, it can only boot from CDs, DVDs, and external hard drives. You may be able to boot into it with rEFIt, however.

What else would I be talking about booting it from?

I thought you were saying that it was impossible to get Linux booted from a flash drive on any device. Looking back, I see how it was implied you were talking about booting from a mac.

[QUOTE=meppers;25772201]so once every single bit in an SDD becomes either a 1 or a 0 how slow would the drive become?[/QUOTE] Depends on the disk. It can be from 2x to 10x slower depending on the controller and speed of the flash chips.

this was an interesting read on the matter: [url]http://www.bit-tech.net/hardware/apple/2010/07/01/mac-ssd-performance-trim-in-osx/7[/url]