Doom 3	Source: id Software

Doom 3 is the most advanced OpenGL game to date. It takes advantage of the latest videocard technology and pushes the processing power of the CPU to its absolute limits. At its highest setting, Ultra quality, texture sizes pass the 500MB mark which means even tomorrow's videocards will have a hard time running everything. The frame rates in the game itself are locked at 60 fps so anything above that point is wasted. Each test is run three times and with the third run being recorded.

Doom3
LQ 640x480	FPS	Ranking
MSI RX800XT-VTD256E	113.8
PowerColor X700 Pro	103.1
Albatron Trinity PC6600	97.6
Albatron Trinity PC6600U	111.4
MSI NX6600GT-TD128 AGP	112.5
Albatron Trinity GeForce 6800GT AGP	112.2
Gigabyte GV-NX66T128D	114.6
Gigabyte GV-3D1 (Single GPU Mode 500/1120)	113.3
Gigabyte GV-3D1 (SLI Mode 500/1120)	108.8
MSI NX6600GT-TD128E (Single)	114.6
MSI NX6600GT-TD128E (SLI Mode)	109
MSI NX6600GT-TD128E (SLI Mode 563/1130)	108.1
LQ 1024x768	FPS	Ranking
MSI RX800XT-VTD256E	105.4
PowerColor X700 Pro	57.2
Albatron Trinity PC6600	55.7
Albatron Trinity PC6600U	74.9
MSI NX6600GT-TD128 AGP	87.4
Albatron Trinity GeForce 6800GT AGP	89
Gigabyte GV-NX66T128D	90.8
Gigabyte GV-3D1 (Single GPU Mode 500/1120)	92.6
Gigabyte GV-3D1 (SLI Mode 500/1120)	107.4
MSI NX6600GT-TD128E (Single)	90.8
MSI NX6600GT-TD128E (SLI Mode)	107.3
MSI NX6600GT-TD128E (SLI Mode 563/1130)	107.4
HQ 1024x768	FPS	Ranking
MSI RX800XT-VTD256E	102.8
PowerColor X700 Pro	54.3
Albatron Trinity PC6600	52.5
Albatron Trinity PC6600U	71.3
MSI NX6600GT-TD128 AGP	84.3
Albatron Trinity GeForce 6800GT AGP	85.9
Gigabyte GV-NX66T128D	88
Gigabyte GV-3D1 (Single GPU Mode 500/1120)	90.1
Gigabyte GV-3D1 (SLI Mode 500/1120)	106.8
MSI NX6600GT-TD128E (Single)	87.9
MSI NX6600GT-TD128E (SLI Mode)	106.4
MSI NX6600GT-TD128E (SLI Mode 563/1130)	107.2
HQ1600x1200	FPS	Ranking
MSI RX800XT-VTD256E	58.4
PowerColor X700 Pro	24.7
Albatron Trinity PC6600	26
Albatron Trinity PC6600U	35.9
MSI NX6600GT-TD128 AGP	43.7
Albatron Trinity GeForce 6800GT AGP	44.8
Gigabyte GV-NX66T128D	45.9
Gigabyte GV-3D1 (Single GPU Mode 500/1120)	47.3
Gigabyte GV-3D1 (SLI Mode 500/1120)	79.3
MSI NX6600GT-TD128E (Single)	45.9
MSI NX6600GT-TD128E (SLI Mode)	74.4
MSI NX6600GT-TD128E (SLI Mode 563/1130)	80.6

Doom 3 benefits greatly from SLI at higher resolutions/settings and overclocking simply makes the dual MSI NX6600GT-TD128E sweeter. As for SLI's gaming potential, these results speak for themselves.