What Should I do to Increase Peformance of my W810?

I have it work on 4GB memory stick and was full. But it has the 'damn' lag time. if i've try to playing high quality video, it's cannot accomodate. but in same condition (i mean playing high quality video), other and newer sony ericsson phones can do it.
how to increase peformance on my W810? in order it's not going slow and have good peformance on it (both).
should i change the processor? is it possible?
i get bored with the 'standard' peformance like this
sorry for my bad english:(

you can't increase it's perfomance more than that. even the K810i which i own lag time when opening high quality videos