Well, if you were memory bound on the chip and prime95 wouldn't give up the bus space, then I expect the cpu usage would drop. The exact particulars of how windows decides what time to give what thread are not well known, but it is unlikely that the search and replace would use much memory - it replaces items as it goes. Unless you mean system ram, which prime95 would not give up, then yeah, all signs point to yes - cpu memory would be allocated to the thread with current priority on the related cpu. Ram shouldn't come into play for a s/r - the OS itself would be stuttering if you couldn't free up that much memory on demand.

What I meant was if Prime95 was using up all the memory [I]bandwidth[/I], not the memory itself.

If my RAM can provide 20 GB/s of bandwidth and Prime95 wants 25 GB/s and Word wants 10 MB/s, does Word have to fight tooth and nail for it, or does Prime95 give up the [I]bandwidth[/I] like it does CPU cycles?