Intel Linux Driver Finally Handles 8x MSAA

[ChrisXY]

Secondly, on Windows there's a very useful option to adjust the different color settings of the monitor directly through Intel's graphics control panel. This is useful for a notebook display, as it doesn't have the physical buttons to adjust RGB settings, so controlling it through the GPU is a good alternative. Is there a way to do something like this in Linux? If there's a way, I haven't found an easy solution yet.

Aaand I'm, the third one answering:

 ~ % xgamma --help
usage:  xgamma [-options]

where the available options are:
    -display host:dpy       or -d
    -quiet                  or -q
    -screen                 or -s
    -gamma f.f              Gamma Value
    -rgamma f.f             Red Gamma Value
    -ggamma f.f             Green Gamma Value
    -bgamma f.f             Blue Gamma Value

[1c3d0g]

Thanks guys. I'm going to look into this further. I basically just need to get the green value to a lower setting, as it's much higher than red and blue (according to dispcalGUI + ColorHug).

[mikkl]

Also, for what it's worth, we actually don't support 2x MSAA---the hardware just doesn't do it. Sandy Bridge offers 4x, and Ivy Bridge offers either 4x or 8x.

Are you sure? I have a HD4000 graphics and in directx games on Win7 I see differences between 2x, 4x, 8x regarding quality.

[Kayden]

Are you sure? I have a HD4000 graphics and in directx games on Win7 I see differences between 2x, 4x, 8x regarding quality.

Really? That's strange...the hardware documentation (page 305) clearly lists only 1x, 4x and 8x. I wonder what they're doing! Thanks for the heads up, we'll have to look into it.

[Ansla]

I guess the real question would be whether there is a difference between 1x/off and 2x

[mikkl]

Really? That's strange...the hardware documentation (page 305) clearly lists only 1x, 4x and 8x. I wonder what they're doing! Thanks for the heads up, we'll have to look into it.

I have tested four games: Half-Life 2, Far Cry, Dirt 2, Doom 3


In Doom 3 I didn't saw differences between the different MSAA modes, maybe just 4xMSAA worked but I'm not sure. Performance differences were seen but no quality difference.

Half-Life 2 1280x1024 max details

AA Off= http://s1.directupload.net/images/120724/emvn8pc8.png
2xMSAA= http://s14.directupload.net/images/120724/ud3lqpu6.png
4xMSAA= http://s14.directupload.net/images/120724/ui53prhp.png
8xMSAA= http://s14.directupload.net/images/120724/nxxpaal8.png

Far Cry 1280x1024 max details
AA Off= http://s1.directupload.net/images/120724/jgxe5cbb.png
2xMSAA= http://s14.directupload.net/images/120724/5b8thpeh.png
4xMSAA= http://s7.directupload.net/images/120724/265t5cuk.png
8xMSAA= http://s7.directupload.net/images/120724/p2art7ki.png

Dirt 2 1280x1024 Dx11 medium details
AA Off= http://s14.directupload.net/images/120724/jsgwfeui.png
2xMSAA= http://s7.directupload.net/images/120724/wpbri8ek.png
4xMSAA= http://s14.directupload.net/images/120724/nn6bvvt2.png
8xMSAA= http://s1.directupload.net/images/120724/5pby49yd.png

testbed: i5-3570k, Intel HD4000, 8.15.10.2761 Windows 7 x64


As you can see 2xMSAA looks different. Worth mentioning 2xMSAA isn't faster than 4xMSAA as you see from Fraps, Far Cry even slower. Maybe 2xMSAA runs emulated somehow or not really good supported by the (Windows) driver?

[mikkl]

Really? That's strange...the hardware documentation (page 305) clearly lists only 1x, 4x and 8x. I wonder what they're doing! Thanks for the heads up, we'll have to look into it.

Really? That's strange...the hardware documentation (page 305) clearly lists only 1x, 4x and 8x. I wonder what they're doing! Thanks for the heads up, we'll have to look into it.

I have tested four games: Half-Life 2, Far Cry, Dirt 2, Doom 3


In Doom 3 I didn't saw differences between the different MSAA modes, maybe just 4xMSAA worked but I'm not sure. Performance differences were seen but no quality difference.

Half-Life 2 1280x1024 max details

AA Off= http://s1.directupload.net/images/120724/emvn8pc8.png
2xMSAA= http://s14.directupload.net/images/120724/ud3lqpu6.png
4xMSAA= http://s14.directupload.net/images/120724/ui53prhp.png
8xMSAA= http://s14.directupload.net/images/120724/nxxpaal8.png

Far Cry 1280x1024 max details
AA Off= http://s1.directupload.net/images/120724/jgxe5cbb.png
2xMSAA= http://s14.directupload.net/images/120724/5b8thpeh.png
4xMSAA= http://s7.directupload.net/images/120724/265t5cuk.png
8xMSAA= http://s7.directupload.net/images/120724/p2art7ki.png

Dirt 2 1280x1024 Dx11 medium details
AA Off= http://s14.directupload.net/images/120724/jsgwfeui.png
2xMSAA= http://s7.directupload.net/images/120724/wpbri8ek.png
4xMSAA= http://s14.directupload.net/images/120724/nn6bvvt2.png
8xMSAA= http://s1.directupload.net/images/120724/5pby49yd.png

testbed: i5-3570k, Intel HD4000, 8.15.10.2761 Windows 7 x64


As you can see 2xMSAA looks different. Worth mentioning 2xMSAA isn't faster than 4xMSAA as you see from Fraps, Far Cry even slower. Maybe 2xMSAA runs emulated somehow or not really good supported by the (Windows) driver?

[mikkl]

Really? That's strange...the hardware documentation (page 305) clearly lists only 1x, 4x and 8x. I wonder what they're doing! Thanks for the heads up, we'll have to look into it.

I wrote you a PN with my test results because I can't post screenshot links here it seems.

[Kayden]

Fascinating, thanks! It's interesting that the performance of 2x is the same as 4x (or worse), while the quality is definitely lower. That makes me suspect that they're actually running the hardware in 4x mode, but configuring the positions of samples differently. Paul and Ian think there may be a way to save some memory by doing some hacks to only use two samples, but that would only work on Ivybridge and seems...dodgy. We're not really sure what the Windows folks are doing.

Based on your information, the 2x multisampling "support" doesn't sound that appealing...not any faster, yet worse quality. So for now, we're planning on sticking with our current implementation: if you ask for 2x, we round up and give you 4x.

[mikkl]

Based on your information, the 2x multisampling "support" doesn't sound that appealing...not any faster, yet worse quality. So for now, we're planning on sticking with our current implementation: if you ask for 2x, we round up and give you 4x.

Of course, for the Windows implementation 2xMSAA is completely useless. Same performance (or even worse in Far Cry) than 4xMSAA makes it useless. I'm curious if this was intended from the Windows driver team or not.