I'm waiting for Excel to finish a recalculation and I notice that the CPU usage as reported by Task Manager occasionally spikes to 51% or 52% on a Pentium 4 with hyper-threading. How is a single-threaded application like Excel 2003 doing this?
Is it just a rounding/estimation error on the part of Task Manager? Or is it something to do with HT allocation i.e. I wouldn't see this happening on a genuine dual-core or dual-CPU machine?