If memory is the limiting factor the de-underclocking wont help. In this case he needs to fatten his slug (nasty work) or remove as many as possible running threads from the memory.
De-underclocking will help if timeout due to excessive cpu load is the reason. Watching memory and cpu consumption while acessing the device may help to give an answer here. But IMHO (and at least for a de-undeclocked slug) the memory is often far more the limitation than CPU.