>(a) Windows 2000 reports a dual CPU system as having _four_ CPUs. This of >course gives concerns about how to optimise distribution of tasks across the >virtual CPUs, given that it is wasteful to have 2 virtual CPUs in the same >physical chip busy whilst the other physical CPU is idle.
Under Windows NT, 2K and XP, the primary CPUs come first, then the virutal cpus. IE on a Dual P4 Xeon, the primarys are 1 & 2, and the secondarys are 3 & 4. 3 is the secondary of 1 and 4 is the seconary of 2. This scales with the number of CPUs installed. >There is also a >software licensing issue for the many commercial products (including Windows) >which are licensed on a per-CPU basis. (Remember that Windows XP Home Edition >supports only one CPU, whilst 2000/XP Professional support only two CPUs.) Both Windows 2K and Windows XP ignore the virutal processors in regards to CPU licensing. Here is a story where someone actually did some benchmarking with hyperthreading http://www.gamepc.com/reviews/hardware_review.asp?review=ppso&page=1&mscssid =&tp= _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
