Actually, the only thing in adv_effects that's ever given my system any pause at all are the HQ 3D Shockwave files.
To test, I subsectioned adv_effects into seperate vp files (each file containing ONE piece of content from adv_effects. IE: one for nebulas, one for shockwave, etc).
I can load all of them BUT shockwave and have little to no fps drop. Running JUST HQ 3D Shockwaves is only slighly better performance wise than running it with everything else.
ECS KT-600A
AMD Semperon 2400+ Retail (1.66 Ghz, 333FSB, NO overclocking, stock w/AS5 Thermal Paste)
2x512 XMS Corsair CMX512-3200 C2PT (2-2-3-5 @ 333)
Sapphire Radeon 9600 XT 256, stock, AGP 8x (Fast Write On), ATI Catalyst 4.12 w/Rage3DTweak 3.9c
Sony Multiscan 500PS 21" 5BNC Flat CRT
Crative Labs Audigy 2 w/OpenAL 1.1
Maxtor 100gb 75k-rpm SATA OS Drive
Saitek Cyborg 3D Gold USB
fs2_open_3.6.9.rc3, Launcher 5.4
game_flags = -spec -glow -env -jpgtga -nomotiondebris -2d_poof -cache_bitmaps -dualscanlines -targetinfo -orbradar -rearm_timer -ship_choice_3d -3dwarp -warp_flash -snd_preload -alpha_env ;
Temperature rattings: CPU under idle: 35c. CPU under Full Load: 42c. CPU under FS2: 38c.