Really slow response from Ubuntu LiveCD

Denver Gingerich denver at
Mon Aug 18 15:49:09 UTC 2008

On Mon, Aug 18, 2008 at 11:29 AM, Bob Jonkman <bjonkman at> wrote:
> Hi all:  Yesterday I was trying to fix someone's really old PC by
> removing Windows98 and installing Ubuntu (7.10).  The PC dates from
> 1999, and holds a maximum of 128 MiBytes RAM. I tried installing more
> RAM, but the  motherboard configuration switches max out at 128 MiBytes
> and additional RAM just isn't recognized.
> With Win98 still on the computer I tried to run the Live CDs Ubuntu
> 7.10 and Kubuntu 7.10 so that I could rescue all his documents by
> copying them to a thumb drive (Win98 doesn't support thumb drives
> without additional drivers).
> Unfortunately, both Ubuntu and Kubuntu were abysmally slow.  It took at
> least 30 minutes to get through the booting and get to a file browser
> so that I could copy the files (which took less than a minute).
> Dragging a window couldn't be done in real time - it took over a minute
> for the window to appear at the new location, and in the meantime the
> mouse cursor was completely unresponsive.
> I also tried Knoppix 4.10 (a CD from 2005), and in comparison it was
> wonderfully snappy and responsive.
> I left Win98 on the computer, since I didn't want to risk such poor
> response with Ubuntu installed.
> Is it possible that Ubuntu would work much better once installed on the
> hard drive?

It will work a bit better because there is a large read/write
filesystem available, but it will still be very slow.  You should use
Xubuntu on older systems.  For more details, see:

> If so, what might be causing the poor performance on the
> Live CD?  Are Live CDs known to be much MUCH slower than installed?

If you don't have much RAM, they will be very slow.  Live CDs have two
file systems available to them: a very slow read-only file system (the
CD) and a very fast read/write file system (a partition carved out of
RAM).  If you don't have much RAM, then you must read directly from
the CD for most operations, which is painfully slow.  Furthermore, the
partition carved out of RAM reduces the amount of RAM available as
general-purpose memory so your system will be slower than usual.

If you have lots of RAM, then the Live CD can cache most of itself in
a RAM partition and then it seldom needs to read from the CD.  Thus it
will be very fast.

On an installed system, the OS has a somewhat slow but fairly large
read/write file system available to it (on the hard disk), which the
Live CD does not have.  So an installed system will be faster than a
Live CD system on a computer with little RAM.

> How come Knoppix was so much better?

Because you used a very old version that was optimized for the systems
of the time, where 128 MB RAM was not uncommon.  An Ubuntu Live CD is
not expected to run properly on a system with 128 MB RAM.  Note that
the Ubuntu system requirements page linked above suggests you use the
alternate install CD (not the Live CD) on a system with less than 384

> I'm sure everything would work better with more memory, but this PC
> hardware isn't capable of more than 128 MiBytes.

As mentioned earlier, give Xubuntu a shot.  I installed it on a
computer with a 500 MHz Celeron and 384 MB RAM and it works just fine.
 It should work fine with less RAM, too.


More information about the ubuntu-ca mailing list