I plan to buy SEVERAL used computers for my small BUSINESS. I am a little confused on which processors are faster than the others in general terms. How would you rank Pentium 4, Pentium D, Pentium 4HT, Duo, and Quad processors. Example: is a duo processor speed of 2.2 faster than a Pentium 4 3.4? Thanks for the help. The advantages of dual core processors are their ability to multitask more efficiently than single processors.  While the clock speed of a single processor may be faster than that of a dual core processor, the dual core has its advantages.A Dual Core CPU can be both faster and slower then a P4, because a Dual Core CPU is in effect, 2 CPUs in one, however, what can happen is a program can be older, and only utilize/use one core, so then you have it running at 2.2GHz, whereas the p4 would offer 3.2GHz


However, this being said, for office/business work, EVEN a 2.0Ghz P4 will be more than plenty to run Word/Excel/Emails.
The more important thing is the AMOUNT of RAM that is in them, you will wast at least 512MB for XP and 1GB for Vista.

Also, unless they are all the same price, (for some weird reason, Dual Core CPUs/motherboards are more EXPENSIVE), the P4 Machines will most definitely be cheaper.