The very end user performance test case : ADSL TV playback

Dear all,
I submit this bug report to propose a very end user performances test case : watching TV over an ADSL connection.

The test configuration:
- Macbook Pro 2G (Core 2 Duo, wireless Atheros AR5008, ATI X1600)
   - OSX Leopard
   - Jaunty 64 bits (out of the box configuration, ATI open source driver, compiz activated)
   - VLC in both case
- Dell Latitude D620 (Core Duo, Intel graphics) with Jaunty 32 bits (compiz activated)

The test case: Watch TV with VLC over the ADSL connection:
- in SD (720*576)
- in HD (1280*1080)

The results :
- Mac - OSX Leopard:
   - SD: image and sound fluent, no drops, perfect
   - HD: image and sound fluent, no drops, perfect
- Mac - Jaunty:
   - SD: not fluent, lot of drops, not watchable
   - HD: not fluent, lot of drops, sound not stable, not watchable
- Dell - Jaunty:
   - SD: image and sound fluent, no drops, perfect
   - HD: not fluent, some drops, sound stable, not really watchablebut much better than the Mac.

I know this is a very general test case, but I submit it to give a direction for searching improvements to make Ubuntu more efficient, and as performant as OSX. So, I can make some additionnal and more accurate and targeted tests to try to isolate which part of Ubuntu are responsible for the bad performances.

Thanks for your participation.