Ubuntu's performance : how to speed up ?

[Thom May]

* Vincent Trouilliez (vincent.trouilliez at modulonet.fr) wrote :

> Now, seeing as hard disk performance seems to greatly affect Gnome's
> performance, and seeing that my 40GB drive is a few years old already, I
> am wondering how much faster modern drives are. Drives being cheap, that
> could be a simple way to speed up Ubuntu a bit, until I can afford an
> expensive motherboard.
> 
> I tested my drive transfer rate with hdparm : "sudo hdparm -t /dev/hda"
> I ran it 3 times, and it's about between 15 and 20MB per second.
> 
> Could someone with a super modern (IDE or SCSI) hard drive, run this
> command so I can get a feel for how much better modern drives are, ie,
> is it worth buying one ? Thanks. :-)

My Serial ATA drive gets about 50MB/sec.

> 
> Last thing, seeing as RAM is cheap, and modern boards can carry huge
> amounts of RAM, and seeing as my  /usr folder weigth "only" 2.0GB of
> data, would it be possible to put say 4GB of RAM on the board, use 2GB
> as norma system RAM, and the other 2GB of RAM to pre-load the
> entire /usr forlder at boot ?
> Is there a mechanism in Linux (Kernel ? or higher-level stuff ?) that
> would allow preloading some data into RAM at boot ?

Ubuntu does this already for the boot process - there's no need to put all
your /usr into RAM, just the files on the critical path. Look at
/etc/init.d/readahead to see how to do it. (This puts files into the page
cache, which means the kernel can access them without disk IO being
required).
Personally, I'd recommend upgrading the amount of RAM you have over anything
else.
Cheers,
-Thom