Much thanks to gimmie and cross21's posts. Your suggestions helped a lot. My situation is much like that of gimmie's.
My system spec:
Duron 1.08G(144*7.5)
256M SDRAM
Geforce2 MX100/200, 32M
It's low-end spec but now I have to managed to get my PES run like this(all tested mode):
640*480, low detail level, windowed: No slowdown
640*480, low detail level, full screen: 60f mid-field, 45-55fps goal area
640*480, medium detail level, full screen: 50-57fps mid-field, 35-50fps goal area
720*480, medium detail level, full screen: ditto
800*600, medium detail level, full screen: ditto
The result shows that resolution doesn't make much difference on my computer, while the detail level does matters.
What I've done and the improvements:
(The settings that, to my understanding, make any difference are followed by (*). The number of (*) shows how important it is.)
Initially the game runs at around 10fps at 640*480, low detail level, full screen, just the matrix effect.
->lower directX sound acceleration
->use rivatuner to set VSync to "off" (*)
->run "Hare", a multimedia opitimization software (*)
Now 30-50fps it is, but every time the game starts the performance is totally random. Sometimes not that slow, sometimes unacceptable. Fortunately I saw this thread.
->Load optimized Bios settings default
->Bios, AGP fastwrite on
->Better DRAM setting
->increase windows system virtual memory
->set text-filtering to high-performance(*)
->disable antialiasing(*)
->uncheck all compatibility settings
->maximize Mipmap LOD bias ajustment
->set desktop color to 16bit
->use 3DAnalyze, check the following options
->force z-buffer(**)
->disable two-sided stencil
->emulate HW TnL caps
->emulate other Dx8.1 caps
->remove shuttering quality mode
->force 16bit z-buffer without stencil(***)
Then I got the current performance.
What I have NOT done:
->double speed
->nVidia Refreshrate fixer
My detonator version is 42.01. I didn't turn on double speed in all of the above tests. The game seems not smooth with that, losing some frames. I really want to know whether or not if gimmie has used it. And having played with medium detail level for a while, I feel the game sucks without the shades and shadows. Will the refreshrate fixer help me to fix the goal area slowdown? I got a fear that it may screw things up.