Intel X25M SSD in a MacBook Pro: Performance Degradation Over Time
Xbench score drops 28%
In December 2009, I convinced my employer, xtendx AG, that I needed one of those groovy new Intel X25M G2 Solid State Drives for my then 18 month old early-2008 MacBook Pro. See "Intel X25M SSD in a MacBook Pro: Before and After Performance Results" for details.
A recent blog post from Jeff Atwood's Coding Horror Blog, "Revisiting Solid State Hard Drives" reminded me about one of the reported caveats of running an SSD: Operating systems that do not support the relatively newish TRIM command suffer from degraded performance over time.
Was my system suffering from this too? Time to break out Xbench again and compare the bechmark's numbers.
| Xbench Scores | |||||
| December 2009 | Sept 2010 | Change | |||
| Disk Test | 182.55 | 130.81 | -28% | ||
| Sequential | 115.18 | 85.05 | -26% | ||
| Random | 439.80 | 283.17 | -36% | ||
| Uncached Sequential Speed Metrics (MB/sec) | |||||
| December 2009 | September 2010 | Change | |||
| Write 4K blocks | 84.12 | 44.57 | -47% | ||
| Write 256K blocks | 61.80 | 39.57 | -36% | ||
| Read 4K blocks | 21.04 | 20.60 | -2% | ||
| Read 256K blocks | 115.20 | 105.79 | -8% | ||
| Uncached Random Speed Metrics (MB/sec) | |||||
| SSD | HDD | Change | |||
| Write 4K blocks | 67.60 | 15.06 | -78% | ||
| Write 256K blocks | 64.64 | 67.85 | 5% | ||
| Read 4K blocks | 8.08 | 10.64 | 32% | ||
| Read 256K blocks | 109.16 | 108.25 | -1% | ||
Bummer!The Xbench score drops ~28%! I have absolutely no explanation for the increased 4k random read performance--my gut says it is some sort of odd aberration. In hind sight, I should have saved several runs of the Xbench results from December and averaged them out.
The lost performance due to Flash-drive specific issues can be resolved with the TRIM command, which OSX does not (yet?) support. Windows 7 and Linux 2.6.33 do support TRIM. Many of the existing 'solutions' for my case involve whipping my existing OSX installation from the disk, cleaning this up, and then restoring my Mac to its previous state. Easily a days work, if everything goes well. There is also diglloydTools's DiskTester, which may help. I'll be playing with that next.
Crap.
Setting up SVN access for Eclipse 3.6 Helios on Mac OSX
For reasons that I'm not interested in, setting up Apache Subversion (SVN) access from inside Eclipse Helios IDE is not a single step action. Below are the steps required to gain access to your SVN repository. Some prerequisites:
- Eclipse 3.6 Helios installed. (Duh.) I'm running the 64-bit version, but expect the installation procedure to be the same for 32-bit machines.
- A MacPorts installation, with the rights to use it.
With the above ready to go, follow these steps:
- Install JavaHL. These are Java-SVN bindings. The Subclipse software that you'll install next from inside Eclipse does not do this for you. You'll do this inside Terminal.
sudo port install subversion +bash_completion sudo port install subversion-javahlbindings - Install Subclipse
- From the Eclipse menu bar: Help >> Eclipse Marketplace...
- Select the 'Popular' button, it'll bring Subclipse to the top.
- Click the 'Install button', which is highlighted in red below for your unicorn-loving convenience.
And after a quick restart, you are good to go!
Curious about the difference between Subclipse and Subversion? Check out "SVN plugins for Eclipse - Subclipse vs. Subversive" at Stackoverflow.com and Karl Fogel's comments at (one of the founders of the Subversion project, as well as one of the original CVS developers) on an Eclipsezone.com thread.
In a nutshell? They are very similar, but Subclipse is more "open".
Default IP address on HP ProCurve 2510G-24 and 2910al switches
There is no static IP assigned
Need to configure that new ProCurve 2510G-24 or 2910al that just showed up, factory fresh? The IP address is assigned via DHCP. I had to check with my DHCP server to work out which address it was.
If there is no DHCP server, then it will self assign an IP in the 169.254.0.0/16 range via Automatic Private IP Addressing (APIPA), aka "zero configuration networking".