Software based or hardware based display controller?

I think you will have great difficulty getting the realtime performance tightly enough controlled to drive such a high-bandwidth display directly in software. In fact I should say I don't think it's feasible.

If you use a big FPGA that can integrate the micro core as well as the display controller (e.g. Virtex4), it will be very expensive. If you use a separate micro with an external FPGA performing only the display functions it will be considerably cheaper, though not exactly a weekend project to get it working.

The cheapest and simplest solution will be to use a micro with built- in display controller. However SXGA is at the upper limit of resolutions typically supported by these parts. You should also be prepared to have a significant performance hit in such a shared-memory architecture because a large proportion of the RAM bandwidth is being eaten by the display DMA.

For anything that specs such a huge resolution, I would automatically go down the PC VGA chipset route.

Are you doing something like a Device Driver ?

I think you are into both hardware and software(Driver) development for displaying high resolution images .

I think, you need not have any RTOS / other OS for this.

FPGA with sufficient RAM, ROM and DMA will be a good choice as you can tune it to your own interest.

Yes, They exist.

Karthik Balaguru