Nov 12 2009
Windows 7 Superfetch
I’m about 2/3 of the way done with writing the Windows 7 tweak guide. I’ve come across an issue that I need some help with. It applies to SSD’s. During my research I found these 2 statements:
“In Windows 7, SuperFetch is automatically enabled for disks that have a low Windows Experience Disk Score and disabled for disks that have a high score.”
Performance Testing Guide for Windows
and
“If the system disk is an SSD, and the SSD performs adequately on random reads and doesn’t have glaring performance issues with random writes or flushes, then Superfetch, boot prefetching, application launch prefetching, ReadyBoost and ReadDrive will all be disabled.” Engineering Windows 7 – Support and Q&A for Solid-State Drives
One problem with the above 2 statements. I have an SSD disk (specifically the Intel X25-M Generation 2). My Windows Experience score for Primary hard disk is 7.7 (out a possible 7.9). This was a clean install to this disk, not a clone or image. According to the above statements Windows 7 should have disabled Superfetch. Windows 7 did not disable the service nor adjust the registry settings. It is visable via Task Manager (SysMain) and is actively using system resources.
I’m interested if anyone has had Windows 7 disable this as they claim.
I would also like to know what qualifies as a high “Windows Experience Disk Score” according to Microsoft. (not really expecting an answer on this)
November 12th, 2009 at 3:46 pm
Are you using another hard disk for storage? Maybe it is not being disabled for that reason? If you are, maybe the service never actually gets disabled, it just doesn’t do anything…like taking out all of the indexed files for the windows search indexer. Just a thought, hope it leads you in the right direction. I have been checking your site TWICE DAILY for the new tweak guide since I installed Win7. Can’t wait!
November 12th, 2009 at 4:00 pm
Sounds to me like you found a bug! Or that the mechanism (or timing) that the OS is supposed to automagically configure this has not been implemetned yet by Microsoft. i.e. they released the documentation but the feature didn’t get released yet.
November 17th, 2009 at 12:58 am
Hi Eric,
I have a Super Talent MasterDrive SX SSD. After a fresh install of 7, System Information indicates the Superfetch State is ‘Stopped’, a Start Mode of ‘Manual’, and Error Control ‘Ignore’. My Windows Experience Index Score for this SSD is 7.6. FYI, the Superfetch state doesn’t change with the addition of secondary non-SSDs. I understand the Intel X25-M Generation 2 had degradation issues with sequential write performance and TRIM compatability, which may or may not have been addressed by an Intel firmware update. Perhaps one or the other (or a combination of both) are the culprits?
-Martin
November 17th, 2009 at 2:34 pm
Hi Martin,
Thanks for the info! Coupled with the info from the “New Intel SSD Downloads” post I’m beginning to think the Intel SSD wasn’t such a good choice after all.