In Part 1 of my SuperFetch Q&A, I began to respond to common complaints about Windows Vista’s and Windows 7′s SuperFetch feature. In Part 2, I’ve compiled yet another round of questions and answers for users who are having severe problems with SuperFetch. Let’s dive right in…
Question #5: Does SuperFetch decrease battery life ?
One of our readers, Mike, raised an interesting point in regarding the operation of SuperFetch:
“Anyone using a computer that operates on batteries, either temporarily, or often, should avoid using SuperFetch. While it does keep popularly referenced application data in memory, the task of pooling all this into RAM, and flushing it if not needed, is a waste of battery power.”
That’s actually an excellent argument since memory usage can be detrimental to battery life. However, I’d argue that SuperFetch actually helps avoid disk drive accesses which (on a traditional mechanical disk) consume far more energy than accessing RAM. When you’re on the road, it’s wise to avoid any unnecessary disk access—and that is what SuperFetch is there for.
Question #6: Does SuperFetch block all other disk I/O?
Some of our readers wonder if SuperFetch is designed to overshadow all other disk operations, meaning that it affects your running applications or tasks:
“As soon as I close any program, SuperFetch immediately tries to fill up that memory, which could take several minutes because of a slow laptop hard drive. During that time, everything is slow, especially hard drive accesses, and the computer sometimes freezes completely until SuperFetch is finished. It looks like nobody at Microsoft considered the effects of slow hard drives on SuperFetch, as it blocks almost all other disk I/O.”
This shouldn’t happen. SuperFetch is designed to be a low I/O priority task; it should never interfere with what’s going on. Even if it’s populating memory (which shouldn’t take long), SuperFetch should not slow down any operation.
Question #7: Is SuperFetch causing my system to crash?
Another reader states that SuperFetch actually caused crashes and that these “blue screens” stopped once SuperFetch was disabled:
“The blue screen would happen each time I opened Office 2010 Outlook immediately after logging in – Page File error. I have disabled SuperFetch, and I haven’t had a blue screen since I disabled it. Any idea what is going on?”
My tip: take a look at “Event Viewer” and the exact ID/event details/file name for the crash. You’ll find these more serious crashes under the “Custom Views/Administrative Events”. If it’s caused by SuperFetch, you’ll see a reference to “Sysmain”.
Question #8: Will SuperFetch reduce the life span of my hard disk?
Readers have also wondered about whether the disk accesses caused by SuperFetch (when it’s populating memory with frequently used data) might cause the hard disk to fail sooner. According to a white paper by Google, there is little correlation between the lifetime of a disk and high usage. The study found that only very young disks and very old (4+ years) have higher failure rates when they are extensively used. This isn’t the case with SuperFetch because it doesn’t cause disk accesses around the clock.
Question #9: Why does SuperFetch crash frequently?
Over at Microsoft’s support forums, I found a lot of entries relating to SuperFetch crashing frequently.
If that’s the case, it’s likely that a third-party program is interfering with SuperFetch. I suggest performing a clean boot to troubleshoot these issues, or use TuneUp Program Deactivator to temporarily disable all third-party programs and narrow down the root of the problem.
My advice: Determine what’s best for you!
It’s really important to make sure that SuperFetch is the actual cause of your problem, otherwise, you may end up losing performance. Here is a summary of the most important tips and troubleshooting steps I’ve covered in this two-part series:
- Make sure that SuperFetch is off on newer/faster SSD drives
- Run some benchmarks on older SSD drives (see below) to find out if SuperFetch is really causing problems
- Run benchmarks like with AppTimer or a boot trace to determine if SuperFetch has a detrimental effect on system performance. Make sure to run these tests with SuperFetch fully enabled as well as when it’s disabled
- Run Process Monitor to confirm if “Sysmain” (SuperFetch) is the root of the problem
I agree that SuperFetch is a great feature, but it’s certainly not a “one size fits all” solution. I even advise you to try working with SuperFetch enabled and disabled for a couple of days and see how your Windows “performs”.