Try making the transition bandwidth on your filters a little wider
(like double their current width)--this will make the FIR filters
> CPU scheduling is generally the responsibility of the operating system
> kernel, *NOT* Gnu Radio. What Gnu Radio does is schedule
> blocks to threads, and the execution of those threads, and CPU
> assignment is up to the kernel. In general, the kernel does a good
> job of CPU scheduling.
> Your problem is probably that your flow-graphs aren't optimal in some
> way, and thus take more system resources than they should.
Yes, I do not why it takes a lot of resources alhough I can see with gkrellm application that my CPUs are about 50-60%, so it is not so bad.