Help needed - how can I improve viewport playback speed?

Hello, I would like to know how to improve viewport playback speed in 2.5 version and I have a couple of questions related to this concern.

The problem - if I make a small animation with the default cube, just changing it’s location for 50 frames, than hit play in the timeline, the viewport shows 24 fps playback
BUT - if a have a human rig doing a jump over a box, playback is 1-2 fps - that’s my problem

what I do know:

  • I’m not expecting 24 fps viewport playback for the rig, but also not the low 1-2 fps
  • turning off subsurf, VBO, all other stuff that’s slowing it down - I managed to get it to 2,3 fps or something like that
  • updating drivers, it is an old Radeon GPU (I am aware that Nvidia is better for blender)
  • I am unable to do OpenGL rendering - I get an error “failed to create opengl off screen buffer” - that’s way I’m trying to preview the animation in the viewport.
  • using 2.49 is a better choice for know but I’m thinking of the future

My questions:

  • do I need to upgrade my hardware and how will that perform? I know it’s old but I manage to do simple stuff: Pentium 4 2 Ghz, ATI A9550, 1 Gb Ram, 80 gb hard disk, 32 bits system.
    So, if I were to go with better specs would I be able to achive that 24 fps for the complex rig? - I don’t care about rendering times just the viewport speed playback. I’m thinking of a laptop (I know desktop are better and a lot cheaper) with i5-450m, 4gb ram, nvidia 4xx fermi card. Even if I don’t achieve 24 fps viewport playback is upgrading the hardware going to have a big impact on it?

  • should I expect a better performance when the 2.5 is going to be released in the stable, final version?

  • is there a way to fix that error “failed to create opengl off screen buffer”, other than changing stuff in user preference? (I played with different settings and nothing changed, I even installed the newest phyton)

Thank you