10

I understand that Superfetch was designed to use RAM for caching with HDDs in mind due to their high latencies, something that SSDs don't have. However, I don't understand how an SSD could outperform RAM.

Does Windows 7 automatically disable Superfetch on systems with fast enough SSDs solely to free up more RAM?

stijn
  • 2,007
  • 1
  • 17
  • 26
Louis Waweru
  • 23,945
  • 39
  • 132
  • 198
  • As an aside for those new to using an SSD with Windows, it is also highly recommended that you disable Disk Defragmenter for the same reasons cited below. A new installation of Windows 7 on an SSD should have Defrag disabled when you install, but upgrading from a standard disk to an SSD will require that it be disabled manually as well. – Justin Scott Jul 25 '12 at 17:18

2 Answers2

5

It is not so much that the SSD that will be faster than the RAM, but that the lifespan of the SSD will be decreased. The benefits don't outweigh the cost.

soandos
  • 24,206
  • 28
  • 102
  • 134
4

The reason why SSD manufacturers recommend turning off SuperFetch is because SSD's can only take so many read/write cycles to the same sector before performance degrades and SuperFetch will read and write to the same sector repeatedly.

Louis Waweru
  • 23,945
  • 39
  • 132
  • 198
David Murray
  • 494
  • 2
  • 4
  • 10
  • 3
    More specifically, Superfetch won't run on drive with high random-access speed http://blogs.msdn.com/b/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx It will still run on other drives (if any) – Martheen Jul 22 '12 at 07:55
  • Over a decade later, to my knowledge, SSDs have advanced so that the same sector will no longer be read to / written from repeatedly. – RockPaperLz- Mask it or Casket Feb 08 '23 at 15:51