Ok, basically I've just gathered different benchies comparing the X1900 XTX with the 7800 GTX 512mb off the most popular websites (well the ones that come up in google first). I've only used the high quality testing results, as thats what I assume players will be playing at. There seems to be a great deal of confusion about which card is better and so on. Results if looked across the board show that both cards are very comparable with no single one demolishing the other, however the X1900 XTX takes the lead more often then not, especially in some of the newer games.
Obviously many already knew this, but just for confirmation, here are sets of results.
Guru3D
7800 GTX 512 / X1900 XTX
SC Chaos theory:
1600x1200 (max settings) 76 / 108
1920x1200 (max settings) 67 / 94
Quake 4
1600x1200 (max settings) 83 / 86
1920x1200 (max settings) 72 / 79
Call of Duty 2
1600x1200 (max settings) 60 / 69
1920x1200 (max settings) 50 / 62
Far Cry
1600x1200 (max settings) 76 / 83
Serious Sam 2
1600x1200 (max settings) 103 / 112
1920x1200 (max settings) 99 / 93
Serious Sam 2
1600x1200 (max settings) 102 / 106
Chronicles of Riddick
1600x1200 (max settings) 107 / 94
FEAR
1600x1200 (max settings) 33 / 51
Halo
1600x1200 (max settings) 87 / 92
Return to Castle Wolfenstein
1600x1200 (max settings) 198 / 200
Doom
1600x1200 (max settings) 73 / 73
ATI leads with 12 - 2 score.
Xibit Labs
7800 GTX 512 / X1900 XTX
Battle Field 2
1600x1200 (max settings) 86.4 / 103.1
Chronicles of Riddick
1600x1200 (max settings) 62.4 / 54.2
Call of Duty 2
1600x1200 (max settings) 40.6 / 53.3
Far Cry
1600x1200 (max settings) 79.2 / 83.8
1600x1200 (max settings + HDR) 59 / 51.5
FEAR
1600x1200 (max settings) 35 / 48
Half Life 2
1600x1200 (max settings) 84.8 / 87.3
Half Life 2 Lost Coast
1600x1200 (max settings) 53.8 / 58
Project Snowblind
1600x1200 (max settings) 91.2 / 71.2
Quake 4
1600x1200 (max settings) 106.3 / 97.1
Serious Sam 2
1600x1200 (max settings) 93.1 / 38.3
U2K4
1600x1200 (max settings) 130.1 / 111.9
Prince of Persia
1600x1200 (max settings) 169.8 / 153.2
Splinter Cell
1600x1200 (max settings) 53.1 / 64.2
Colin McRae 2k5
1600x1200 (max settings) 94.4 / 100.3
Pacific Fighters
1600x1200 (max settings) 70.2 / 48.7
Age of Empires 3
1600x1200 (max settings) 45.9 / 40.9
Warhammer 40K DOW
1600x1200 (max settings) 62.1 / 46.3
Nvidia leads with 10 - 8 score.
Rage3D
7800 GTX 512 / X1900 XTX
FEAR
1600x1200 (max settings) 35 / 48
1920x1200 (max settings) 26 / 37
Quake 4
1600x1200 (max settings) 102.9 / 98.5
1920x1200 (max settings) 92.8 / 88.8
Battlefield 2
1600x1200 (max settings) 69.6 / 75.3
1920x1200 (max settings) 61.6 / 70.1
Splinter Cell CT
1600x1200 (max settings SM3) 53.4 / 62.9
1920x1200 (max settings SM3) 46 / 54.9
Half Life 2 Lost Coast
1600x1200 (max settings) 53.7 / 49.7
1920x1200 (max settings) 43.6 / 42
Half Life 2
1600x1200 (max settings) 113.2 / 116
1920x1200 (max settings) 104.3 / 109.5
Doom 3
1600x1200 (max settings) 103.7 / 97.1
1920x1200 (max settings) 89.5 / 83.8
Chronicles of Riddick
1600x1200 (max settings) 61.5 / 54
1920x1200 (max settings) 52.5 / 46.5
Far Cry
1600x1200 (max settings) 81.1 / 88.8
1920x1200 (max settings) 71.7 / 80.1
Pacific Fighters
1600x1200 (max settings) 106.9 / 76.6
1920x1200 (max settings) 90.3 / 69.9
Draw with 10 - 10 score.
Hexus
7800 GTX 512 / X1900 XTX
FEAR
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Splinter Cell CT
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Far Cry
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Black and White 2
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Quake 4
1600x1200 (max settings) Nvidia win
1920x1200 (max settings) Nvidia win
ATI leads with 8 - 2 score.
Hot Hardware
7800 GTX 512 / X1900 XTX
Splinter Cell CT
1600x1200 (max settings) 54.89 / 61.11
FEAR
1600x1200 (max settings) 36 / 49
Far Cry
1600x1200 (max settings) 72.74 / 86.53
Half Life 2
1600x1200 (max settings) 134.97 / 134.07
Doom 3
1600x1200 (max settings) 81.3 / 73.4
Quake 4
1600x1200 (max settings) 50.2 / 46.7
Draw with 3 - 3 score.
GD Hardware
7800 GTX 512 / X1900 XTX
Call of Duty 2
1600x1200 (max settings) 37 / 49
FEAR
1600x1200 (max settings) 32 / 54
Half Life 2 Lost Coast
1600x1200 (max settings) 55 / 90
Quake 4
1600x1200 (max settings) 114 / 141
ATI leads with 4 - 0 score.
Anandtech
7800 GTX 512 / X1900 XTX
Battlefield 2
1600x1200 (4xAA) 66.2 / 75
1920x1440 (4xAA) 51 / 59.6
Black and White 2
1600x1200 (max settings) 29.6 / 20.7
1920x1440 (max settings) 23.8 / 16.5
Day of Defeat
1600x1200 (max settings) 36.1 / 54.7
1920x1440 (max settings) 22 / 40
Far Cry
1600x1200 (4xAA) 69.8 / 79.8
1920x1440 (4xAA) 52.3 / 64.7
FEAR
1600x1200 (4xAA) 31 / 51
1920x1440 (4xAA) 23 / 38
ATI leads with 10 - 2 score.
Firing Squad
7800 GTX 512 / X1900 XTX
HL2 Lost Coast
1600x1200 (max settings) 78.7 / 83.1
1600x1200 (max settings + HDR) 64.7 / 71.4
Battlefield 2
1600x1200 (max settings) 89.4 / 114.6
Quake 4
1600x1200 (max settings) 85.3 / 76.8
FEAR
1600x1200 (max settings) 37 / 50
Call of Duty 2
1600x1200 (max settings) 32.3 / 37.6
Serious Sam 2
1600x1200 (max settings) 75.1 / 71.7
1600x1200 (max settings + HDR) 57.3 / 64.4
ATI leads with 6 - 2 score.
Total = ATI wins with 61 - 31 (high quality testing results)
Obviously many already knew this, but just for confirmation, here are sets of results.
Guru3D
7800 GTX 512 / X1900 XTX
SC Chaos theory:
1600x1200 (max settings) 76 / 108
1920x1200 (max settings) 67 / 94
Quake 4
1600x1200 (max settings) 83 / 86
1920x1200 (max settings) 72 / 79
Call of Duty 2
1600x1200 (max settings) 60 / 69
1920x1200 (max settings) 50 / 62
Far Cry
1600x1200 (max settings) 76 / 83
Serious Sam 2
1600x1200 (max settings) 103 / 112
1920x1200 (max settings) 99 / 93
Serious Sam 2
1600x1200 (max settings) 102 / 106
Chronicles of Riddick
1600x1200 (max settings) 107 / 94
FEAR
1600x1200 (max settings) 33 / 51
Halo
1600x1200 (max settings) 87 / 92
Return to Castle Wolfenstein
1600x1200 (max settings) 198 / 200
Doom
1600x1200 (max settings) 73 / 73
ATI leads with 12 - 2 score.
Xibit Labs
7800 GTX 512 / X1900 XTX
Battle Field 2
1600x1200 (max settings) 86.4 / 103.1
Chronicles of Riddick
1600x1200 (max settings) 62.4 / 54.2
Call of Duty 2
1600x1200 (max settings) 40.6 / 53.3
Far Cry
1600x1200 (max settings) 79.2 / 83.8
1600x1200 (max settings + HDR) 59 / 51.5
FEAR
1600x1200 (max settings) 35 / 48
Half Life 2
1600x1200 (max settings) 84.8 / 87.3
Half Life 2 Lost Coast
1600x1200 (max settings) 53.8 / 58
Project Snowblind
1600x1200 (max settings) 91.2 / 71.2
Quake 4
1600x1200 (max settings) 106.3 / 97.1
Serious Sam 2
1600x1200 (max settings) 93.1 / 38.3
U2K4
1600x1200 (max settings) 130.1 / 111.9
Prince of Persia
1600x1200 (max settings) 169.8 / 153.2
Splinter Cell
1600x1200 (max settings) 53.1 / 64.2
Colin McRae 2k5
1600x1200 (max settings) 94.4 / 100.3
Pacific Fighters
1600x1200 (max settings) 70.2 / 48.7
Age of Empires 3
1600x1200 (max settings) 45.9 / 40.9
Warhammer 40K DOW
1600x1200 (max settings) 62.1 / 46.3
Nvidia leads with 10 - 8 score.
Rage3D
7800 GTX 512 / X1900 XTX
FEAR
1600x1200 (max settings) 35 / 48
1920x1200 (max settings) 26 / 37
Quake 4
1600x1200 (max settings) 102.9 / 98.5
1920x1200 (max settings) 92.8 / 88.8
Battlefield 2
1600x1200 (max settings) 69.6 / 75.3
1920x1200 (max settings) 61.6 / 70.1
Splinter Cell CT
1600x1200 (max settings SM3) 53.4 / 62.9
1920x1200 (max settings SM3) 46 / 54.9
Half Life 2 Lost Coast
1600x1200 (max settings) 53.7 / 49.7
1920x1200 (max settings) 43.6 / 42
Half Life 2
1600x1200 (max settings) 113.2 / 116
1920x1200 (max settings) 104.3 / 109.5
Doom 3
1600x1200 (max settings) 103.7 / 97.1
1920x1200 (max settings) 89.5 / 83.8
Chronicles of Riddick
1600x1200 (max settings) 61.5 / 54
1920x1200 (max settings) 52.5 / 46.5
Far Cry
1600x1200 (max settings) 81.1 / 88.8
1920x1200 (max settings) 71.7 / 80.1
Pacific Fighters
1600x1200 (max settings) 106.9 / 76.6
1920x1200 (max settings) 90.3 / 69.9
Draw with 10 - 10 score.
Hexus
7800 GTX 512 / X1900 XTX
FEAR
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Splinter Cell CT
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Far Cry
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Black and White 2
1600x1200 (max settings) ATI win
1920x1200 (max settings) ATI win
Quake 4
1600x1200 (max settings) Nvidia win
1920x1200 (max settings) Nvidia win
ATI leads with 8 - 2 score.
Hot Hardware
7800 GTX 512 / X1900 XTX
Splinter Cell CT
1600x1200 (max settings) 54.89 / 61.11
FEAR
1600x1200 (max settings) 36 / 49
Far Cry
1600x1200 (max settings) 72.74 / 86.53
Half Life 2
1600x1200 (max settings) 134.97 / 134.07
Doom 3
1600x1200 (max settings) 81.3 / 73.4
Quake 4
1600x1200 (max settings) 50.2 / 46.7
Draw with 3 - 3 score.
GD Hardware
7800 GTX 512 / X1900 XTX
Call of Duty 2
1600x1200 (max settings) 37 / 49
FEAR
1600x1200 (max settings) 32 / 54
Half Life 2 Lost Coast
1600x1200 (max settings) 55 / 90
Quake 4
1600x1200 (max settings) 114 / 141
ATI leads with 4 - 0 score.
Anandtech
7800 GTX 512 / X1900 XTX
Battlefield 2
1600x1200 (4xAA) 66.2 / 75
1920x1440 (4xAA) 51 / 59.6
Black and White 2
1600x1200 (max settings) 29.6 / 20.7
1920x1440 (max settings) 23.8 / 16.5
Day of Defeat
1600x1200 (max settings) 36.1 / 54.7
1920x1440 (max settings) 22 / 40
Far Cry
1600x1200 (4xAA) 69.8 / 79.8
1920x1440 (4xAA) 52.3 / 64.7
FEAR
1600x1200 (4xAA) 31 / 51
1920x1440 (4xAA) 23 / 38
ATI leads with 10 - 2 score.
Firing Squad
7800 GTX 512 / X1900 XTX
HL2 Lost Coast
1600x1200 (max settings) 78.7 / 83.1
1600x1200 (max settings + HDR) 64.7 / 71.4
Battlefield 2
1600x1200 (max settings) 89.4 / 114.6
Quake 4
1600x1200 (max settings) 85.3 / 76.8
FEAR
1600x1200 (max settings) 37 / 50
Call of Duty 2
1600x1200 (max settings) 32.3 / 37.6
Serious Sam 2
1600x1200 (max settings) 75.1 / 71.7
1600x1200 (max settings + HDR) 57.3 / 64.4
ATI leads with 6 - 2 score.
Total = ATI wins with 61 - 31 (high quality testing results)