I just knew Gnash is 100% of all YouTube videos should work, its true. Also true for Flash Ads. I dont know if its about my hardware, drivers, or libraries, its performance is worse than Adobe Flash 64-bit. Yes, you can spank me, I am still using Adobe Flash 64-bit. I was aware Adobe decided to hold their support for 64-bit and I did not try to switch to 32-bit with nspluginwrappers help. I was risking myself.
Anyway, I had tried everything I could with ~/.gnashrc. I had tried every combination for hwaccel and render. I even tried vaapi, even I knew its purely meaningless since my ATI X1400 is not supported, I was desperate.
Here is some numbers. YouTube 480p using Adobe Flash 10.0 r45: 20-25%, 40-45% in fullscreen. My processor is a dual-core, so 45% means it uses almost one cores processing power. 360p using Gnash 0.8.8: 40%, nearly 100% and very laggy in fullscreen. If I use xv in mplayer for a 720p video, its around 20-25% in fullscreen.
This is my second try of Gnash, first time was probably a year ago, it didnt work out last time. Next time I try Gnash, it will be version 1.0.
I hope its just configuration thing, though I dont think so, but if you have same video card and it works smoothly for you, please tell me about your settings.