As I found out here, certain things related to visual effects can really slow KDE down on netbooks and other low-end hardware. For me the biggest offender was ARGB visuals. This can apparently be turned off (with seemingly minimal impact on usability) by exporting KDE_SKIP_ARGB_VISUALS=1... Which is okay for Linux geeks like me, but not so okay for newbies.

Thus, I suggest that the next version of KDE have an option somewhere in the configuration center to disable ARGB visuals, maybe with text indicating that this option may improve performance on some machines. If it improves things on even a few other computers as much as it did on my netbook, it might help put a dent in complaints that KDE4 is incurably slow.

You can disable transperency in the desktop effects settings.

AFAIK that doesn't have the same effect though - doesn't that only apply to composite based effects? Or do I have something completely wrong?

It is probable that this option isn't provided because it is simply a hack which disables functionality, which will therefore not result in the graphics drivers getting fixed (which ultimately improves the whole system)

Ah okay. In that case though, I have to ask - wouldn't it be better disable that functionality by default, with an environment variable that can be exported to turn it on so that developers can still experiment with it? Creating pressure to fix the drivers makes sense, but IMHO a desktop environment like KDE, which will be used on a lot of different types of computers, should not rely by default on features that are known to be broken for a subset of those computers.

I hope I'm not coming across as rude here BTW... But I used KDE3 for a while, and it performed very well on a variety of machines (including a 350 MHz Pentium II with 192 MB of RAM). And now that KDE4 is relatively mature, it's failing to perform as well on more powerful hardware that really should have no problem with it... Hardware that doesn't have a problem with Gnome 2, or Xfce, or KDE3 for that matter.

Which version of Kubuntu and KDE are you using?

11.04, with KDE 4.6. But FYI I've found KDE4 to be sluggish with every version and every distribution I've tried, up until I found out about the KDE_SKIP_ARGB_VISUALS hack.

(Also FYI, I'm chiefly using machines with Intel GPUs.)

What types of Intel cards? i5, i965?

Sorry... All the machines use i945. This was a very common video chipset a few years back.

The i945 is quite common still, and is unfortunately a very problematic card when it comes to the current linux drivers unfortunately. Continuing with your workaround and continuing to upgrade may yield improvements in the long term, as the Intel driver is fixed in general.