Flash very slow

[drad]

Hello all
I have recover a old dell gx240 and I have chosen to install linux mint 13 mate .
Fast specs :
CPU~Single core Intel Pentium 4 CPU (-UP-) clocked at 1695.161 Mhz Kernel~3.2.0-23-generic i686 Up~51 min Mem~393.9/748.0MB HDD~40.0GB(12.6% used) Procs~132 Client~Shell inxi~1.7.33

first vga agp attempt:
description: VGA compatible controller
product: Rage 128 Pro Ultra TF
GLX Renderer: Gallium 0.4 on llvmpipe (LLVM 0x300) GLX Version: 2.1 Mesa 8.0.2
direct rendering: Yes

But system speed slighty slow and youtube flash very slow.
So i try with a other vga card :
Card: NVIDIA NV28 [GeForce4 Ti 4200 AGP 8x] bus-ID: 01:00.0
X.Org: 1.11.3 drivers: nvidia (unloaded: fbdev,vesa,nouveau) Resolution: 1680x1050@53.0hz
GLX Renderer: GeForce4 Ti 4200 with AGP8X/AGP/SSE2 GLX Version: 1.5.8 NVIDIA 96.43.23 Direct Rendering: Yes

vga glxgears compare :
r128 = max 70 fps
ti4200 (mesa) = max 500 fps
ti4200 (nvidia) = max 3000 fps
Also moving mouse considerably slow down alltimes system and fps
So with new vga the system is faster but flash speed don't change! Random speed playback, freezes, and huge cpu process usage.
Video player like totem is also really slow. It freezes directly on picture so unwatchable. But vlc really works great no problem.

Is there a solution please? I would like to use this computer for simple tasks.

[drad]

After long search i'm happy to report the solution! Just need in firefox to install greasemonkey plugin + viewtube script.
For low config choose LD FLV preset. Maybe also in gnome mplayer plugin settings add x11 video output and hardware acceleration.
Even with my first crappy vga the videos are watchable now.