Sunday, May 27, 2012

Windows 7 and SSDs 2 : Setup secrets and tune-up tweaks


Solid-state drives are wicked fast. SSDs start and shut down fast, and they perform read operations (especially random reads) at speeds that blow the doors off conventional hard drives. In the first installment of this series, I gathered the numbers to show just how much faster you can expect an SSD to perform in the real world.
But you might need to jump through some setup hoops to get top performance out of an SSD-equipped PC running Windows 7. That’s because Windows has evolved over many years with features that specifically target the behavior of conventional hard disks. Features like Superfetch and Prefetch and ReadyBoot are designed to monitor files you access at startup and when you launch programs and then arrange them on the disk for optimal access. Because SSDs don’t have motors and spindles and platters and magnetic heads, they don’t benefit from those features and need to be handled differently.
In fact, there are a series of steps that must be performed before an SSD can perform to its full potential on a Windows PC. Skip any of those steps and the results can be disappointing.


Don’t miss the rest of this series:

My own personal experience bears this out.
Back in October 2009, I bought a Dell Latitude XT2 with a 256GB SSD. One of the first things I did was to replace the Dell-supplied copy of Windows XP Professional with Windows 7 Professional. Disk performance was reasonably fast, but it certainly wasn’t jaw-dropping, and the disk score in the Windows Experience Index was stuck stubbornly at 5.9.
I did a little research last summer and learned that a lot of Dell customers were experiencing the same disappointment with this particular hardware combination. The problem was that the hardware—a Samsung PB22-CS3—needed a firmware update to work properly with the advanced disk-handling features in Windows 7. That update had to come from Dell, and as of last July, it wasn’t available.
A third-party utility, CrystalDiskInfo, confirmed that this disk did not offer support for the TRIM command, which is one of the key requirements for proper SSD operation. (Using the TRIM command allows the system to properly erase blocks of data in the background; for an explanation, see this excellent article by Anand.) Windows 7 supports the TRIM command natively; earlier Windows versions don’t.
Over the holidays, I decided to check again and was pleasantly surprised to learn that Dell had released a firmware update for this drive several months earlier. Because the firmware update wipes out all data on the drive, I had to do a clean install of Windows 7.
The performance difference was like night and day. And benchmark results show why. Here are the Windows System Assessment Tool (WinSAT) results from July 2010 (original OEM configuration) and then from December 2010 after updating the SSD firmware and installing the latest Intel storage drivers:
Disk throughput (bigger=better)OriginalOptimized
Sequential Read (MB/s)151.9219.39
Random Read (MB/s)10.77130.25
IO/Responsiveness (smaller=better)OriginalOptimized
Average IO Rate (ms/IO)4.291.14
Grouped IOs (units)15.438.94
Long IOs (units)36.692.65
Overall Responsiveness (units)566.0123.72
Disk score capped at 5.9?YesNo
With the new setup, the disk subscore in the Windows Experience Index jumped from 5.9 to 7.4, and the difference is noticeable. The system is 13 12 times faster in random reads, which is what makes the most profound difference in everyday operation.
Updating the firmware was the key that unlocked the performance of this device, but it isn’t the only crucial step. On the next page, I list the steps you need to go through to ensure that an SSD performs properly with Windows 7.

source:http://www.zdnet.com

No comments:

Post a Comment