Transcend ExpressCard 32GB SSD Performance in a MacBook Pro
Is a Transcend SSD ExpressCard a compelling option to speed up your MacBook Pro? No.
Last December I upgraded my MacBook Pro with an Intel X-25M solid state drive, and posted the impressive performance metrics on this blog. (Intel X25M SSD in a MacBook Pro: Before and After Performance Results.) It was an expensive upgrade, but well worth it.
A coworker of mine, Mattia, expressed an interest in upgrading his MBP but was concerned about the costs. Then I heard about how Rob Griffiths of MacWorld installing and booting OSX on a Wintec Filemate 48GB , which seemed to have two key benefit over HDD replacement:
- a less disruptive change (as the ExpressCard slot can be utilized, rather than breaking open the case to replace the original hard disc)
- Lower costs since the capacity of the disk only needs to cover the operating system--most data can remain on the built in hard disk.
With this in mind, we purchased a 32GB Trancsend SSD ExpressCard. But before installing OSX, we ran some Xbench performance metrics to see how the disk compared to both the installed 7,200 RPM hard drive and my own current Intel SSD. The results were disappointing:
| Intel X-25M SSD | 7.2k RPM HDD | Transcend SSD | |
| Sequential Uncached 4k blocks write | 45.91 | 48.5 | 28.24 |
| Sequential Uncached 256k blocks write | 44.47 | 59.06 | 25.98 |
| Sequential Uncached 4k blocks read | 23.07 | 12.86 | 7.14 |
| Sequential Uncached 256k blocks read | 108.7 | 60.09 | 36.13 |
| Random Uncached 4k blocks write | 71.75 | 0.93 | 2.00 |
| Random Uncached 256k blocks write | 41.49 | 27.39 | 23.55 |
| Random Uncached 4k blocks read | 10.34 | 0.53 | 6.85 |
| Random Uncached 256k blocks read | 107.47 | 22.14 | 35.18 |
And graphed for your viewing pleasure:
My intereptation? The Transcend SSD's performance characteristics are in the same general range as a quick-ish mechanical disk. Yea, the random reads* are a bit faster, but nearly as stunning as the X-25M's metrics. The case for using a Transcend SSD as a boot disk is at best 'not compelling'.
* = Small random reads are important to speeding up one's computer as that is the type of activity the operating system does frequently. Reading this configuration file, executing that small binary, etc.
We are not going to bother installing OSX onto the Transcend ExpressCard SSD as a replacement for Mattia's MBP boot disk. The benefits are just not there.
BufferedInputStream's Default Buffer Size Compared to Moore's Law
2nd in a series of posts about java.io.BufferedInputStream's Default Buffer Size
BufferedInputStream Default Buffer Size Series: Previous | Next
We can see that Java's BufferedInputStream (BIS) default buffer size has grown over time. I thought it would be interesting to compare it against other metrics in Computer Science, the most famous of which is Moore's Law, which I compared with BIS in the first post. The second time around, I have the data points from describing the capacity of hard disks sold during the years since Java's debut.
Finally, below, the data points from Wikipedia's List of device bit rates were used to compare the BIS size with the speed of storage bus speeds.
A pattern is emerging. And this will be covered in my next blog entry.
BufferedInputStream Default Buffer Size Series: Previous | Next