I recently bought an SSD to put in my MacBook Pro 15-inch, Late 2008 model. I blindly plumped for an OWC, specifically:
120GB Mercury Electra 3G SSD 2.5″ Serial-ATA 7mm 3Gb/s Solid State Drive. Tier 1 NAND Flash storage with 7% Over Provisioned Redundancy. Mac and PC compatible. Built in the USA. 3 Year OWC Limited Warranty.
I installed a fresh copy of OS X 10.9 on the drive, and started enjoying the speed. But then I noticed something bad. Every time I woke up the laptop from sleep, I would get about 30 seconds of use before everything slowly froze, normally at the point of a Spotlight search or attempting to refresh a website that felt like it had frozen.
First I Googled for firmware updates, but it was clear that my drive had the latest firmware OWC had to offer.
Many forum entries and articles recounted similar woes:
It became apparent that SSDs with a “SandForce” processor can have problems with sleep, or more specifically, hibernation, although it isn’t consistent. I contacted OWC who agreed to replace the drive, even offering to contribute $25 towards international postage from here in the UK back to Illinois (kudos for good customer service). However, I thought I’d better investigate whether changing from default settings might mitigate the problem. Mainly thanks to Martin’s Weekend Coding blog, I appear to have prevented the problem recurring by turning off hibernation:
Turning off hibernation in OS X Lion+
The following commands turn off hibernation and remove the sleep image (which was 4GB on my Mac):
$ sudo pmset -a hibernatemode 0 $ sudo rm /var/vm/sleepimage
For more details, read Martin’s blog: http://blog.alutam.com/2012/04/01/optimizing-macos-x-lion-for-ssd/#hibernation
Other optimisations for third-party SSDs
I decided to try out some of the other settings recommended on Martin’s blog:
- Trim Enabler. I originally tried this tool for enabling TRIM support, but then found that it is not necessary or recommended for OWC drives. YMMV. http://blog.macsales.com/11051-to-trim-or-not-to-trim-owc-has-the-answer
- Turn off the Sudden Motion Sensor. This doesn’t seem useful for a solid state drive.
- Turn off Hard Disk Sleep. Again, no point for a drive with no moving parts.
There were a few other settings that seemed rather drastic, so I’ve avoided them. I’ll report back if there are any problems!
The problem seems to have returned with an upgrade to Yosemite, despite verifying that hibernation has not been reinstated. More investigations to come! My advice for now would be don’t upgrade to Yosemite if you have an OWC SSD and a 2008 MacBook Pro!