Both Resident Evil games run great, RE4 better than RE5 of course, but both totally playable.

Resident Evil 4

Running great, 12-35 FPS

Before you start playing you need to use SetupTool to setup graphics, you can find it in folder where game is installed (C:\Program Files (x86)\Resident Evil 4).

If you cannot set resolution you want with setup tool than do next.

Find SetupTool.ini in same folder where SetupTool.exe is.
Open it with notepad and set next:

Mode=0 (0=FullScreen ,1=Window ,Other=Window)
Type=0 (0=Wide ,1=Normal ,Other=Normal)
SizeX=1280
SizeY=768

I prefer these settings, but you can set whatever you want.

Screenshots:
SCREENSHOT 1
SCREENSHOT 2
SCREENSHOT 3
SCREENSHOT 4

Resident Evil 5

Runs in nice fps, very tweakable.
12-24 FPS depends on settings.

I use next:

OPTIONS > SYSTEM SETTINGS

SCREEN RESOLUTION 800x600
VERTICAL SYNC OFF
FRAMERATE UNLOCKED
ANTI-ALIASING OFF
MOTION BLUR OFF
SHADOW DETAIL LOW
TEXTURE DETAIL MEDIUM
OVERALL QUALITY LOW

With these settings I get 10-22 FPS very smooth.

I use MEDIUM on texture detail because if I set it to low my mouse movements doesn't feel natural.
Also play game in DirectX 9 mode not DirectX 10.

You can also lower resolution more with configuration file, and also tweak something else.
Config is in C:\Users\YOUR-USER-NAME\Documents\CAPCOM\RESIDENT EVIL 5
Edit config.ini, for resolution change Resolution= (example 640x480)

Screenshots:
SCREENSHOT 1
SCREENSHOT 2
SCREENSHOT 3
SCREENSHOT 4