Memory is still an order of magnitude faster than your “very fast SSD”.

dingaling · on Nov 11, 2013

And memory is still an order of magnitude more expensive than SSD, per GB.

I just bought 4 GB of PC-6400 for a laptop at £40. A fast 128GB SSD is £100.

Summary: use RAM judiciously

stephencanon · on Nov 11, 2013

All the more reason for your OS to use memory aggressively. Surely you don't want your expensive investment sitting around just doing nothing?

Unused memory is wasted memory.

sp332 · on Nov 11, 2013

The prefetched data is managed by the OS. If a program needs the RAM, the prefetched data is immediately discarded. Prefetching never creates RAM pressure.

voidlogic · on Nov 11, 2013

This. It blows my mind how many people who write software don't understand how OS caching and virtual memory work. They are great filter interview questions ;)

alcuadrado · on Nov 11, 2013

just one?

stephencanon · on Nov 11, 2013

At least one. Potentially more. The actual multiple depends strongly on the specific SSD and memory configurations in question, and on the benchmark of interest.