@Torkyo,
Your 4350 is too weak to do frame delay at interlaced super resolutions (e.g. 2560x480 requires a huge bandwidth). In my experience the bare minimum to support that is HD 6xxx and above. Others (cools) have had success with some 4350s anyway.
The solution is to edit user_modes_super.ini and remove the anything above 288p, then add some normal 4:3 modes to the list such as 664x496@60, 688x512@60, 704x528@60 (the resulting refresh will be lower, depending on your monitor preset).
You may still see some static tearing on the top of the screen. If that's the case, use -vsync_offset as suggested above, but start with much lower values, e.g. 16 and go increasing that in steps of 16, for instance (schmerzkaufen uses lcd).
Thank you very much,
Luckily I don't go interlacing as I got a good Hantarex Polo Star tri sync monitor and I've been able to set up the screen very well also for vertical games, many runs at 16200 kHz, other 25 and 31kHz without to interlace.
I did't realise that the video card had a rule in the frame delay matter! I was thinking that everything was over CPU shoulders...
Anyway now I understand why in games like Shienryu (320x240) it is impossible to me to use frame delay. it isn't a matter of CPU, it is the GPU!
In game like Raiden (256x224 59.60 Hz switcher 2560x256P 59.60 Hz 16211 KHz) I could keep frame delay set to 8 without stuttering or slowdown. the game is perfect apart that static tear on the top of the screen. This is the same for the most of my favourite games: without that static tear the game would be perfect with frame delay set to 8 and even 9 (Slap Fight/1942/1943/Psychic/Gyrodine/Road Fighter/ etc).
Shienryu to me runs perfect without frame delay with a switcher resolution of 2560x496P 59.765 Hz 31.556 KHz but as you can guess, even if I set frame delay to 1, the game severely stutters and have slow downs.
So far the only way I found to reduce a bit the input lag for vertical games is to use the D3D9EX groovymame patch but there is a tangible difference (in terms of input latency) between D3D9EX and a good Frame delay set to 8. there is more than frame, 1,5 in my tests.
So thanks for your suggestions, I'm going to edit user_modes_super.ini the way you suggested and try to fix also the static tear using the -vsync_offset although I don't know at all the -vsync_offset option.
I let you know my progress.
thanks