7" Display - Qt Graphic Performance

Hi!

I use kernel 2.6.29 from git://repo.or.cz/linux-2.6/mini2440.git and
Qt4.5.3. Everything works fine on my T35 and on the A70 Display with one
restriction: Performance! As a sample, Qt's FluidLauncher Demo runs smooth
on the 3,5" Display but leaks and hacks on the 7" Display. 

Whats our opinion why the Performance difference is so big?
 - The 7" Display handles five times more Pixel information than the 3,5"
 - The 3,5" Display uses faster Response Timings (seen in Kernel Source)
 - Another Idea?

Big question is: Is that problem solvable?

with best regards
Kurt

Hallo Kurt,
does you 7"LCD works fine including touch screen? I have compiled OE
including QT4.4.3 and QT4.6 on 7"LCD but all fonts are very small and touch
screen works strange. It is properly calibrated via ts and also ts_test
works fine but immediately when I start QT application it works strange. I
suspect maybe wrong DPI is being calculated by QT. 
I was not able to find anything about this issue...
thanks, vlado

Im in the same situation, my 7" has very abd performace too.. any solutions
on that one?

Hi,

Yes i had same problem too. I should point that driving 7" will take 5
times more bandwith than 3.5" so this performance issue is normal. On the
other hand 2440 boards have 100MHz SDRAM. I think this is the bottleneck of
2440 boards. I've overclocked my board. While running rams with 133MHz,
I've get better performance. (According to the datasheet RAM can run on
133MHz. So this is not really an overclock. There's no risk.)

I've also realized that old Qt versions' performance is better. Qt 3.5.x
bundled with Qtopia 2.2.x works faster than new Qt versions.

Best regards