> I am using Casio E-125. When can we see a significant speed boost? Thanks.
>

I hate to say it, but if you have an E125 you should probably be running the mameboy build instead of mamece3.

For example:
Galaga on MameCE3: 7 fps in attract mode
Galaga on Mameboy: 20 fps in attract mode

My E125 is overclocked to 200mhz, but even on a stock unit mameboy would be faster. And, as a side note, Mamece3 runs about 1fps faster on my Ipaq 3835 than it does on my E125.