I have a 2.8 ghz cpu that I can move to another machine given that this one will work.  The site is haveing a sale I wondered if there is a differnce between a 3 ghz cpu and one that is 3E ghz.  Does it allow more threads an how do I know if my board will support such a thing.  Not hyperthearding.Could you give us a link?
I believe the E would EITHER denote hyper-threading or a faster bus.yes, it seems like a good enough of a deal for what I would be useing it for.  http://www.geeks.com/details.asp?invtid=P43000E478&cat=CPU  I wanted to switch the one in my gaming machine with this one.  That's a Pentium 4 socket 478, Prescott CORE.  The E means it supports Hyper-Threading and has an 800MHz FSB, rather than 533, as well as 2MB of L2 cache rather than 1MB.
Be sure your cooling can handle it, those chips run hot  I got a large heatsink but not sure if the board will support it ether since its a prescott http://www.intel.com/support/motherboards/server/se7210tp1-e/This link will give you the supported processors.
Using this list of P4 processors from Wikipedia, you can match that processor on Geeks to four different CPU codes (SL7E4, SL7KB, SL7PM, SL79L), all of which are supported by that board.
Hope this helps.ummmmmmm.......... sadly now cause I dont get any of that an just want to know if it will handle it being a prescott, ALSO I see that it will run a celeron D would that be better to get?  I dont have any thing in terms of heatsink that would probably work with it though just wondered for sake of speed if its good priced as well.  OK ... that board will support that processor, yes.
A Celeron D would be worse in terms of performance.   It would be???  I thought that its the equilvent of a pentium d and the start of daul core?Nope.
The Celeron D is a Celeron with a little more cache ... it's better than an equivalent Celeron but not as good as a P4.
Pentium D was completely different.
The naming is definitely confusing.Just keep in mind where the Celeron came from- as a Low-cost alternative to some of Intel's pentium processors. As such they are also stripped down. I believe that is still true.from what I still know of, I know why do that?