TRIM Enabler, The Benchmark System, And Software
Again, Apple supports TRIM through OS X, but only when you use one of its OEM drives. Swap out for something else and TRIM gets disabled. We've heard the horror stories about turning it back on through third-party utilities, which is why in our previous piece we did this the hard way:
"Fortunately, the restriction isn't hardwired. There's a bit of terminal window work to lift the Apple SSD requirement, but it's all covered in sufficient depth at Github."
This time, for brevity's sake, we went ahead and gave the TRIM Enabler app a try. It's about as easy to use as you might imagine. Slide a lever from left to right and you're good. Just be aware that operating system updates tend to reverse this process, so you'll need to repeat it if OS X gets patched.
Before TRIM Enabler can be used, the option to allow software installations from anywhere (and not just from the App Store and identified developers) needs to be set in the operating system's settings.
Benchmark System and Software
We're using a MacBook Pro for our benchmark system. To be more specific, it’s the smallest version of the eleventh generation that was introduced in mid-2012, also known as the MacBookPro9,2 model.
The notebook originally came with a 500 GB hard drive, which we took out and dropped into an external USB 3.0 enclosure. Samsung's 840 Pro SSD takes its place. We booted the system from the original hard drive.
| Apple MacBook Pro | |
|---|---|
| Model | MacBook Pro |
| Model Number | MacBookPro9,2 |
| CPU | Intel Core i5-3210M |
| CPU Clock Frequency | 2.5 GHz |
| Number of Cores | 2 |
| L2 Cache (per Core) | 256 KB |
| Shared L3 Cache | 3 MB |
| RAM | 4 GB |
| System Hard Drive | Seagate ST500LM012 (500 GB; 5400 RPM) |
Benchmark Software
We’re sending the Samsung 840 Pro SSD though two rounds of benchmarks. First, we perform a secure erase, which tells the controller to clear all blocks on the drive. This resets the SSD to the state it shipped in, yielding the best possible performance. We then complete the first round of benchmarks, which consists of running AJA System Test and DiskTester twice without TRIM. This provides a good comparison between fresh out of box and well-used performance.
For the second round, we perform another secure erase, and then we send it through the two benchmark passes with TRIM enabled. This gives us a total of four results:
- TRIM disabled, first pass (brand new)
- TRIM disabled, second pass (well used)
- TRIM enabled, first pass (brand new)
- TRIM enabled, second pass (well used)
A detailed account of a round of benchmarking:
- Only for second round: Install TRIM Enabler and reboot MacBook Pro
- Start AJA System Test benchmark (benchmark file size 16 GB)
- Start DiskTester benchmark (block sizes 4 KB and 8 KB)
- Have DiskTester fill entire SSD with data three times to simulate use
- Fill entire SSD with video data
- Take 30-minute break
- Start AJA System Test benchmark (benchmark file size 16 GB)
- Start DiskTester benchmark (block sizes 4 KB and 8 KB)
