Western Digital SiliconEdge Blue Review: WD Enters the Consumer SSD Marketby Anand Lal Shimpi on March 3, 2010 12:00 AM EST
- Posted in
Random Read/Write Speed
This test reads/writes 4KB in a completely random pattern over an 8GB space of the drive to simulate the sort of random access that you'd see on an OS drive (even this is more stressful than a normal desktop user would see). I perform three concurrent IOs and run the test for 3 minutes. The results reported are in average MB/s over the entire time.
I've had to run this test two different ways thanks to the way the newer controllers handle write alignment. Without a manually aligned partition, Windows XP executes writes on sector aligned boundaries while most modern OSes write with 4K alignment. Some controllers take this into account when mapping LBAs to page addresses, which generates additional overhead but makes for relatively similar performance regardless of OS/partition alignment. Other controllers skip the management overhead and just perform worse under Windows XP without partition alignment as file system writes are not automatically aligned with the SSD's internal pages.
First up is my traditional 4KB random write test, each write here is aligned to 512-byte sectors, similar to how Windows XP might write data to a drive:
Random write performance is at the lower end of the Indilinx spectrum, but definitely competitive in that space. Obviously even as a slower SSD the SiliconEdge Blue is an order of magnitude faster than even the fastest desktop hard drives.
The chart below shows that the SiliconEdge Blue performs the same regardless of whether you align transfers to 4KB boundaries or not:
Random read performance is the only area where Western Digital's SSD actually noticeably falls behind the Indilinx drives:
At 21.8MB/s it's much faster than a hard drive, but a good ~15MB/s slower than an Indilinx drive. It is in the same class of performance as the Toshiba based SSDNow V+ and the Samsung RBB based drives.