Snow Leopard support TRIM?

icedbullet

icedbullet

icedbullet

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Hey all

I'm getting a base spec Macbook Pro tomorrow and I may put my Intel X25-M ssd into it.

I have been looking around the web and even asked an apple employee (who didn't know what TRIM was) and it seems that TRIM isnt supported. Now I'm an apple noob and this will be my first ever mac. Does a mac need TRIM? Will I suffer performance degradation using my SSD?
 
Ive had an SSD in my mac pro for around 12 months I think. It's now about 70% full ajd vie not noticed a performance drop. It has slowed slightly but nowhere near as much as what it did over the same time period on a normal HDD.

SSD is the best thing I've put in my Mac pro so TRIM or not, do it!
 
icedbullet said:
I thought a Mac didn't suffer a performance drop after time like a windows pc does?
Click to expand...

Why wouldn't it?

Before anyone says it, it DOES suffer from it.

See: http://forums.macrumors.com/showthread.php?t=841182

Before is ~2 months use, after is when it's been copied, wiped, Intel Toolbox'd and then copied back, IE a secure erase.
ssdperformance.jpg


As you can see, 33% drop in just 2 months...

Just before anyone chimes in regarding XBench, for relative performance it's totally acceptable to use. Besides I've witnessed the 80MB/sec -> 0 -> 80 transfer speeds when the SSD is used, so that in my mind confirms what XBench is saying.

Score now after two weeks: 225!
 
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I have an SSD in my MBP, and have had since day 1 - first upgrade I did. Well worth the money.

The units do degrade when written to - it's known as write fatigue. You can return the units back to factory ship by using the on-board secure erase facilities.

Problem is that to my knowledge this can only be done on a PC based architecture, not on a Mac.

Wrote about that process here: http://www.markc.me.uk/MarkC/Blog/Entries/2009/8/13_Erasing_an_SSD.html

A lot of the effect is in benchmarking though. I often don't bother write-erasing mine even when I know it's fully fatigued. Sure, it's a *bit* faster, but not massively so. Still spanks a physical drive in performance.
 
It won't be anything as good as doing a write-erase. In fact I'm surprised that works at all. The SSD f/w won't care what is in each sector - zeros or not. How would it know you just want to store zeros :confused:

May give it go though and see what happens :D
 
xrs said:
I go into disk utility and write - zeros to all free space. Seems to help performance for me.
Click to expand...

NO! That does NOT do anything but make the situation WORSE. My Xbench score dropped to about 150 when I did that!!

All that does is write zeros to the disk making the sectors FULL, IE not setting them as 'empty'. It is not a SSD secure erase!!

When I get a free moment I will do a proper write up but for the moment I will make it simple.

YOU NEED TO DO A SSD SECURE ERASE TO GET THE PERFORMANCE BACK!!!

Options are:

1. Use Intels SSD Toolbox in Windows
2. Boot from a CD with HDDErase on it.
 
The usual state for erased flash chips is ones. Therefore I'd be setting all free space to 0xFF. However with wear levelling etc would the drive's firmware see this as a fake TRIM or see it as a write and mess it all up?
 
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