Adding value to my Mac...

Hi all,

i just wanted to write some words about my new system disk and since this is kind of hardware...
ok, here it goes.

I bought an OCZ Vector 150 480MB SSD for my Mac.

+ Speed
– Price

Pro model
+ write endurance: 5 years warranty x 50GB/day vs. 3 years warranty x 20GB/day
– Price

And now Apple enters the Scene...

I have a "late 2009 iMac" which means:
1. Apple does not like me to open it
2. There's a proprietary thermal sensor built in the current drive
   which is not documented but required or the fans spin up to maximum
3. Apple deliberately does not support TRIM for non-Apple SSDs

ad 0: Copy data to new drive: I copied all data with Carbon Copy Cloner from bombich.com beforehand from the internal HDD to the SSD which i had attached to the USB interface of my external backup drive. This took exceptional long, probably because i have some GB of hard linked files on it.

ad 1: Open the iMac: find a pair of suction cups and a dust-free working place.

ad 2: Thermal sensor problem: I found sources which said it's a 2N3904 transistor which sounds reasonable but there were signs for doubt: Shorting these 2 pins should silence the fan as well though shorting would move the measured voltage in the wrong direction. On the other hand in the mid 2009 model it is a transistor. So it might be. I consulted some data sheets and prepared to attach a BC337 as an external sensor.

When my iMac was open i measured the diode voltage at the two pins of the HDD and found in one direction slightly more than 1V and in the other direction 0.36V which says: no, it's not a transistor. Nevertheless i attached the prepared transistor in the most likely direction. I can only guess now that it's in fact a 1-wire sensor.

After restarting my Mac the fans sped up. For that "worst case" i had already downloaded SSD Fan Control from exirion.net. I installed it.

Unluckily the OCZ Vector does not have an internal temperature sensor, so the "intelligent" mode of SSD fan control does not work. I had to set a fixed value.

ad 3: TRIM support: As in it's worst days when they were nearly broke Apple tests whether the found drive is one Apple provides itself and disables TRIM support for others. TRIM support informs the SSD which blocks are deleted in the file system and from now on do not need to be updated whenever neighbor blocks are written thus speeding up writing and reducing write wear on the SSD. So i ran the already downloaded TrimEnabler from cindori.org. This patches a kernel extensions, which means: it overwrites the test for the found model.

Unexpected Problem

When i wanted to fit the SSD in it's 3"5 adapter into the iMac i found that OCZ uses metric screws whereas Apple is still stuck to 'imperial' units.

Cast in Order of Appearance:

The Backup took exceptionally long: 3:30 hours for 232GB.

The SSD with the included 3"5 adapter

The SSD attached to the USB interface of my external backup HDD.

The sensor which did not work. Also additional wire would not have been required.

When lifting the front glass there was immediately lots of dust sucked in and settled on the display.
No chance to avoid this. (the screw is only to help auto focus)

My iMac with the old HDD, a Seagate Barracuda.

The SSD with the (not-working) sensor on it's 3"5 adapter fitted to the iMac's mounting bracket.
I had to find a way around that metric/imperial problem and placed the mounting bracket between adapter and SSD and pinched it with two screws.

The SSD placed in my iMac.

Especially program start now noticeably faster. I think it was worth it.

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