RAM access time is normally measured in:

Nanoseconds (billionths of a second)
  • Seconds
  • Microseconds (millionths of a second)
  • Milliseconds (thousandths of a second)

You certainly don't wait for seconds each time your computer accesses the RAM.

Compared to other things going on in the computer (such as access disk, which takes thousandths of a second), RAM access is very fast.