Listen up, maggot.  So you're getting shitty frames?
Gonna cry to mommy like a VS cocksucker?  Or are you going to do something about it like a real man, a TR man?
Fuck yes you are.

PS2 is a piece of shit that doesn't like using your shiny master race CPU.
These settings will shift a lot of the work away from it, and onto your GPU instead.
Your game should run smoother and look prettier into the bargain.
If the second part of this sounds better than the first, you're a VS nancy boy.

Start the PS2 launcher, and click the small blue hexagonal spanner/wrench icon on the bottom right hand side - advanced settings - and click "open game directory".
Open up UserOptions.ini in notepad (or your preferred text editor).

Copy/paste these settings over the existing sections.  Just do it, don't ask why - you can work it out later with Google if you want.

[Rendering]
GraphicsQuality=4
TextureQuality=0
ShadowQuality=1
RenderDistance=1000.000000
Gamma=0.000000
MaximumFPS=120
UseLod0a=0
VSync=0
OverallQuality=-1
LightingQuality=2
FogShadowsEnable=0
EffectsQuality=3
TerrainQuality=4
FloraQuality=1
ModelQuality=4
ParticleLOD=2
MotionBlur=0
AO=0
VerticalFOV=74


[Sound]
Master=1.000000
Music=0.500000
Game=1.000000
Dialog=0.500000
UI=1.000000
UseFloat32Output=0
ExclusiveMode=0
HitIndicator=1
LowAmmoIndicator=1
VehicleChatter=0
SampleRate=44100
MaxVoices=45

Make sure you're running fullscreen at your monitor's native resolution.

Everything is now cranked up to MAX (or near enough for your purposes) except shadows and flora because these kill only your CPU.
You can turn shadows off totally and get more frames guaranteed by setting ShadowQuality=0, but it looks like ass so don't do it unless you have to.

Now start up PS2 and look in your graphics settings.  Everything that was Low/Medium/High but is now blank is on ultra settings.
Don't touch these in-game because you can't set ultra without editing UserOptions.ini.
Everything that shows a value can still be played around with, such as render distance, render quality or FOV.

Pressing ALT+F in game will show your current frames in the bottom left of the screen, along with your current bottleneck - GPU or CPU.
If this shows CPU and your frames are still too shitty, you should now try turning shadows off.
If it shows GPU with shitty frames, try turning down lighting, particles or effects until it gets better.
If all else fails, try a lower resolution.

NOW FUCK OFF AND IMPRESS THE BRASS