Max resolution of Intel Graphics Chipsets

[Roland Scheidegger]

On 01.07.2008 01:55, Erwin Rol wrote:
> On Tue, 2008-07-01 at 01:26 +0200, Tomas Carnecky wrote:
>> Erwin Rol wrote:
>>> Hello all,
>>> 
>>> I am looking for a solution where I can connect two TFT's of
>>> 1440x900, and display different images on those TFT's.
>>> 
>>> Most Intel chipsets support two independent outputs, but it seems
>>> that the internal framebuffer is the limiting factor here. I
>>> would need 2880x900 or 1440x1800 (the layout is not important).
>>> 
>>> For example, do I understand correct that for example the Intel
>>> 915 chipset does support two outputs of 1440x900 (or even
>>> larger), but that the internal framebuffer only can be 2048x1536?
>>> 
>>> 
>>> I checked several Intel chipsets and they all seem to be
>>> "limited" to 2048x1536. Are there Intel chipsets that can do for
>>> example 2048x2048, so it can fit a 1440x1800 resolution?
>> $ xrandr Screen 0: minimum 320 x 200, current 1920 x 1200, maximum
>> 4096 x 1440 ...
>> 
> 
> Weird the datasheet mentions a maximum resolution of ; - Supports
> flat panels up to 2048x1536 @ 60 Hz or digital CRT/HDTV at 1920x1080
> @ 85 Hz
That's not really "framebuffer" size just what the ramdac (in case of
analog) or single-link tmds is capable of.

> 
>> This is on a i965 chip. But I'm sure the vertical resolution could
>> go much above the 1440. In any way, 2048x2048 is only the
>> limitation of the 3D engine, if you don't need OpenGL (compiz,
>> games etc), the limit is much higher. And i965 has the 3D limit at
>> 8192x8192, only older chips have the above mentioned 2048x2048.
>> 
>> tom
> 
> Is the some list somewhere with what the Intel Graphic chips can and
> can not do ? Like maximum 2D/3D/video-overlay resolution, maximum 
> framebuffer size, etc. ?
Older (and some not so old) intel chips (everything up to gen 3.5, i.e.
not gen4 (i965) based can do 2kx2k for 3d (both textures and drawing
rectangle), and gen4 can do 8kx8k (textures and drawing rect). According
to the comments in i830_exa.c all these chips can do 2d operations to
larger resolutions than you'd care (32kx64k - I think you had some
trouble allocating enough ram for this :-)).
Textured video source size is obviously limited to what the 3d texture
size is (but driver limited to 2048x2048), overlay source video size
would be 2048x2048 (i915 and newer) but driver limits this to 1920x1088
due to allocation problems.

Roland