Which operating system is best for SSDs?
- — 12 December, 2008 07:59
However, one difference between Vista and XP is that Vista, by default, enables background drive defragmentation -- something that isn't necessary with an SSD and can actually wear out the drive more rapidly. While most laptop and PC resellers disable background defragmentation on Vista systems that ship with an SSD, anyone installing or upgrading to Vista may not know they should do that to preserve SSD life, Klein said.
To turn off Vista's auto defragmentation feature, a user would go to the Start menu, then the Control Panel and then choose Control Panel Home. Next select "System and Maintenance" and under the Administrative Tools section, choose "Defragment your hard drive." Vista then allows a user to check or uncheck the Run automatically function.
According to Howard Butler, vice president of technical support at Diskeeper, hard disk drives and SSDs both benefit from defragmentation utilities in operating at peak efficiency. Data may be laid down in contiguous clusters on an SSD, just as with hard disk drives; as it's deleted, space is freed up. But those pockets of free space may be left unused. Defragmentation helps by consolidating data and free space, Butler said.
Joseph Unsworth, an analyst at Gartner, said Vista's SuperFetch feature gives Vista a boost over XP with regard to SSDs because it can preload often-used applications into system memory so they're ready when needed. Vista introduced the concept of low-priority I/O, which enables background processes to run with lower-priority access to the hard drive than other programs.
Unsworth installed Intel's X25 SSD on a PC running Vista and said he was impressed with the boot-up times over the hard disk drive he replaced. While there are now more than 90 SSD vendors, Unsworth said he prefers drives from Intel, Samsung and STEC, which he said offer advanced architectures with multiple channels to NAND flash chips set up in a parallel. For example, Intel has 10 channels on its X25-M SSD. In multichannel NAND architecuters, each parallel channel represents multiple streams of data to multiple NAND chips, yielding greater sustained throughput -- and speed.
When will operating systems be optimized?
Even if operating systems aren't yet optimized for SSDs, they likely will be as the technology gains ground. Last month, at its Windows Hardware Engineering Conference (WinHEC), Microsoft promised that its upcoming Windows 7 would work better with SSDs.
Unlike Vista, Windows 7 will turn off disk defragmentation when it detects an SSD instead of a spinning disk drive. Windows 7 will also delete "garbage" data in advance. That would head off garbage collection, which can add latency -- a major factor in the slower write speeds often seen in SSDs.
Microsoft also plans a certification program for SSDs so that the drives properly identify themselves to Windows 7 and prioritize data I/O for the SATA interface.
Regardless of what Microsoft does, Unsworth said he believes that Apple will have the advantage because its OS is closed, meaning Apple can drive its own development initiatives and will likely do so when it comes to SSD optimization.
Apple also plans to launch Mac OS X 10.6, a.k.a. "Snow Leopard," which is expected to trim overhead and optimize it for faster I/O.
"I have to believe they will, and I've told them and recommended to them, wouldn't it be awfully compelling to get boot up with an SSD in under 10 seconds?" Unsworth said. "How easy would that be to convey as a selling point to the consumer?"