just 150MB/s write in Blackmagic Disk Speed :(

Legacy SanDisk Products Ultra II Internal SSD
1

I’ve bought Your (new) SSD. I’ve got Macbook Pro mid-2012.

I’ve did ‘clean’ install Mac OSX Yosemite (latest system) - installed program Blackmagic Disk Speed test to check SSD speed - read is ok (about 500MB/s) but write speed is slow (about 150MB/s) which is far away from 500MB/s.

Thing is - I’ve installed Windows 8.1 on my Macbook - and everything is ok - got about 500MB/s  read and write.

What is wrong with latest Mac OSX Yosemite? Especially even if I did “fresh” install system.

2

Hello,

the speeds you are getting seem to be line SATA 1 so you have to ensure that the hardware of the mac is compatible with the drive and is of course sata 3. also the trim function of the ssd is deactivated on a mac from default so maybe that was the issue with the mac?

3

if the Mac has the Nividis MCP79 SATA chipset this is the fastest speed you can get. The MCP79 Chipset has compatibility issues with SSDs and will not link at its SATA 3Gb speed. it will only link at SATA 1.5Gb. This is an nvidia chipset issue and since the chipset is no longer made it is not going to be fixed from what I have read.