3 ms·

And drain your battery for no reason.

• hansbogert 13y ago
  Do you have any proof of that? "Free" memory uses as much energy as "used" memory, there is no distinction in SD|DDR-RAM. And if the OS is smart, it only has to keep a simple index of memory pages still relevant. I'd argue that this has a measurable battery-hit.
  • jeltz 13y ago
    Reading from the SSD to laod it into RAM does drain battery. No idea if it is enough to matter though.
  • runako 13y ago
    You're only accounting for the RAM power. Accessing the SSD costs power, too.
    • tedunangst 13y ago
      Then I think I'd rather Windows prefetched my programs while I'm plugged in so it doesn't have to do so when I'm on battery.
    • tanzam75 13y ago
      > You're only accounting for the RAM power. Accessing the SSD costs power, too. A typical modern SSD reads at 500 MiB/s, consumes 3 watts when reading, and 0.3 watts when idle. A stick of DDR3 RAM consumes about 3 watts, just sitting idle. The power consumption from prefetching is minor compared to that of the RAM.