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
HQ 1024x768	FPS	Ranking
MSI RX1800XT-VT2D512E	123.7
Gigabyte GV-RX18L256V-B	112.1
ATi Radeon X850 XT PE	116.9
MSI RX800XT-VTD256E	109
ATi Radeon X800 XL	101.8
PowerColor X700 Pro	54.3
MSI NX7800GTX-VT2D512E	123.6
MSI NX7800GTX-VT2D256E (Single)	123.5
MSI NX7800GTX-VT2D256E (SLI Mode)	121.9
Asus EN7800GT 2DHTV/256M/OSP/A (Single)	125.3
Asus EN7800GT 2DHTV/256M/OSP/A (SLI Mode)	127
MSI NX6800GT-T2D256E	112.6
MSI NX6600GT-TD128E (Single)	92.4
MSI NX6600GT-TD128E (SLI Mode)	116.2
Albatron GeForce 6600-512	53
PowerColor X800 GTO	74.4
PowerColor X800 GTO (438/378)	80.4
HQ1600x1200	FPS	Ranking
MSI RX1800XT-VT2D512E	84
Gigabyte GV-RX18L256V-B	63.6
ATi Radeon X850 XT PE	66
MSI RX800XT-VTD256E	58.4
ATi Radeon X800 XL	52.5
PowerColor X700 Pro	25.9
MSI NX7800GTX-VT2D512E	106.1
MSI NX7800GTX-VT2D256E (Single)	97.6
MSI NX7800GTX-VT2D256E (SLI Mode)	117.6
Asus EN7800GT 2DHTV/256M/OSP/A (Single)	87.2
Asus EN7800GT 2DHTV/256M/OSP/A (SLI Mode)	118.3
MSI NX6800GT-T2D256E	70.4
MSI NX6600GT-TD128E (Single)	47.4
MSI NX6600GT-TD128E (SLI Mode)	79.4
Albatron GeForce 6600-512	26.2
PowerColor X800 GTO	36.9
PowerColor X800 GTO (438/378)	40.2
UQ 1024x768	FPS	Ranking
MSI RX1800XT-VT2D512E	122.7
Gigabyte GV-RX18L256V-B	102.4
ATi Radeon X850 XT PE	113.1
MSI RX800XT-VTD256E	104.5
ATi Radeon X800 XL	97.8
PowerColor X700 Pro	52.8
MSI NX7800GTX-VT2D512E	125.4
MSI NX7800GTX-VT2D256E (Single)	122
MSI NX7800GTX-VT2D256E (SLI Mode)	121.9
Asus EN7800GT 2DHTV/256M/OSP/A (Single)	121.2
Asus EN7800GT 2DHTV/256M/OSP/A (SLI Mode)	124.3
MSI NX6800GT-T2D256E	111
MSI NX6600GT-TD128E (Single)	87.5
MSI NX6600GT-TD128E (SLI Mode)	115.3
Albatron GeForce 6600-512	49.6
PowerColor X800 GTO	55.4
PowerColor X800 GTO (438/378)	55.7
UQ 1600x1200	FPS	Ranking
MSI RX1800XT-VT2D512E	82.6
Gigabyte GV-RX18L256V-B	58.8
ATi Radeon X850 XT PE	63.8
MSI RX800XT-VTD256E	56.2
ATi Radeon X800 XL	51
PowerColor X700 Pro	21.9
MSI NX7800GTX-VT2D512E	106.7
MSI NX7800GTX-VT2D256E (Single)	96.7
MSI NX7800GTX-VT2D256E (SLI Mode)	118.8
Asus EN7800GT 2DHTV/256M/OSP/A (Single)	84.2
Asus EN7800GT 2DHTV/256M/OSP/A (SLI Mode)	116.7
MSI NX6800GT-T2D256E	69.3
MSI NX6600GT-TD128E (Single)	46
MSI NX6600GT-TD128E (SLI Mode)	79.7
Albatron GeForce 6600-512	25.1
PowerColor X800 GTO	27.7
PowerColor X800 GTO (438/378)	27.8

Doom 3 is a very complex game and since the PowerColor X800 GTO only has 128MB of DDR memory, it does not perform very well at all. High quality mode at 1024x768 resolution is decent I guess, but anything else is simply too much for this mainstream PCI Express videocard. Overclocking does not help the X800 GTO's situation.