Saturday, June 20, 2015

Should I be worried about my Prefetch/Superfetch settings in Windows 7 on a SSD drive?



I just installed Windows 7 on my new OCZ Vertex 2. I heard that Win7 is optimized for use with SSDs and disables the prefetcher if one is detected, but I decided to check anyway. So I looked at




HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters





...and noticed that "EnablePrefetcher" and "EnableSuperfetch" are both set to 3. Why is this and should I set these to 0 to save my drive?



This webpage: http://blogs.msdn.com/b/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx says:




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.




So theoretically it's possible for these settings to be enabled on 'inadequately performing' drives, but I wouldn't expect it from my new drive...




I will also add that




fsutil behavior query disabledeletenotify




yields 0 for my drive, so according to this question: Confirming that Windows 7 is using SSD optimizations it means that it's recognized as an SSD. Also, it doesn't appear in the Disk Defragmenter's schedule.


Answer



Windows doesn't disable the prefetching services just because you install an SSD. If you have both an SSD and a hard drive you would still want the prefetching for programs on the hard drive, so Windows doesn't disable it entirely. What it does is disable prefetching of content on the SSD. If you have nothing but the SSD then you can go ahead and disable it in windows.




Beyond updating drivers and the Windows Experience Index there is nothing you need to do.


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