OC Workbench has posted another ECS K7S5A FAQ
For those who wish to overclock your ECS K7S5A and found no easy tool to do that, our forum contributors have writeen a utility call CHFSB which modifies parts of CMOS to overclock your system.Read more
They have also written a FAQ on how this utility can be used and provide some technical information on how they reversed engineered.
Users have tried it and it works.