Windows 7 and SSDs, Part 2 (Tweaking the box)
As described in Part 1 of this series, Windows 7 has built-in optimizations for Solid State Disks (SSDs). To this purpose, Windows 7 will check random reads speeds of your disks, to determine whether the system is equipped with such a disk.
These optimizations include disabling defragmentation on the SSD, and, when the disk is the system disk, disabling SuperFetch and ReadyBoost. On SSDs that support the functionality TRIM is enabled. The optimizations serve to improve the performance of your system without negatively impacting the lifetime of the disk. More information can be found here.
Sometimes, after you inserted a disk that Windows characterizes as a fast disk, (some of) these optimizations are not applied.
Before you begin
Please make sure you have applied the latest firmware for the Solid State Disk (SSD) device and the latest version of the driver for the IDE controller. Also, make sure you have a valid backup of important data on your system, before applying these tweaks.
Tweaking Windows 7 for SSDs
To manually tweak your system change the following settings:
Disabling defragmentation on the SSD device
By default, Windows 7 will disable the default defragmentation schedule for a SSD. This, however, does not mean the ‘Disk Defragmenter’ service (defragsvc) gets disabled. When the system is also equipped with non-SSD disks, the defragmentation schedule still applies to these disks.
When you open the Defragmentation program from the Start menu, located in the accessories, system folder) the Operating System will have disabled the schedule for the partitions located on Solid State Disks. When it is not excluded in the list, exclude it manually by editing the schedule, select disks, and then deselect the partitions on SSDs.
Disabling Superfetch and ReadyBoost
When the Solid State Disk is in use as the system disk, SuperFetch may be disabled. Since SSDs are multiple times faster than HDDs for these random reads SuperFetch only hogs up memory without a big reason.
To disable SuperFetch stop the SuperFetch (sysmain) service from the Services MMC Snap-in (services.msc). When it is is stopped, disable the service in the properties of the service.
In systems with traditional HDDs, USB media may offer faster random read access, but in a system with the pagefile on a SSD, the maximum USB throughput limit (480Mb/s) is reached earlier than the throughput of the IDE controller (133MB/s), rendering the ReadyBoost functionality useless in contrast with the pagefile on the SSD.
You do not need to perform any additional actions to disable ReadyBoost. Since it uses the same service as SuperFetch.
Prefetch places often-used pieces of executables into RAM and is one of the new tricks in Windows 7 to make it (seem to go) faster. Disabling this feature frees up system RAM and allows the SSD to run like it was meant to.
To disable Prefetch open the Registry Editor (Regedit.exe). Once you are in the register follow this path:
The registry value to chance here is named EnablePrefetcher. Change its value to 0. You must restart your system for the changes to take effect.
When your SSD device supports TRIM, you can enable the TRIM support in Windows 7.
First off, we need to find whether TRIM is already turned on, meaning Windows 7 is already sending TRIM commands to the disk. To find out, type the following command:
fsutil behavior query DisableDeleteNotify
When the result is 0, Windows is actively sending TRIM commands to the disk. When it’s return value is 1, it isn’t and it’s best to enable it.
To enable TRIM support in Windows 7, type the following command:
fsutil behavior set DisableDeleteNotify 0
Support and Q&A for Solid-State Drives
Super User: How do I know if my SSD Drive supports TRIM?
Microsoft Windows 7 SSD Performance Comparison
TRIM performance In Windows 7, Enabling, Tips & Tricks, Supported SSDs
Windows 7 optimized for SSD – solid state drives
Intel releases SSD firmware and SSD Toolbox (Trim) for Windows 7
Windows 7 Disk Defragmenter User Interface Overview
Windows, TRIM and other SSD Mysteries