[tlug] Possible command to boost to laptop performance

[Dave M G <dave@example.com>]

TLUG,

A while ago someone was looking for ways to squeeze more performance out
of their laptop.

Recently, I came across this simple command which seems to help.
Actually, it helps a heck of a lot, though it does raise questions.

The command is this:

 sudo sh -c "sync; echo 3 > /proc/sys/vm/drop_caches"

I found it on an Ubuntu forum, so it may be most help to Ubuntu users.
No promises for other Linux flavours.

I find that on my Ubuntu laptop, running this when the memory and cache
usage seems high (going by the memory/cache monitor graph Gnome panel
applet) will cause the memory and cache to drop by half or more. Not
always, but often enough. As a result, the laptop seems to perform
better, as I think it's swapping less.

However, despite assurances on the forum that this command is harmless
and the fact that I've been using it for a few days without any ill
effects, I'm still a little sceptical that I've found a magic command
for improving performance.

Is it just that Ubuntu and/or Linux is inefficient about memory/cache
handling on its own?

What surprises me most is that when my laptop boots, the memory/cache is
already fairly heavily occupied. Running this command knocks it down
considerably, and thereafter I get optimum performance when opening and
switching programs.

So what the heck is Ubuntu loading right off the bat that I don't seem
to need at all? And if it's the case that the things it's loading into
memory are that useless, might I just go ahead and make that command
part of the startup applications?

Surely there is some drawback here I'm not seeing.

Or am I just being overly pessimistic?

Any advice would be much appreciated.

-- 
Dave M G