Physical Differences between Pentium 4 and Xeon?

[JihadJim]

Background: My dad is thinking of building a dual Xeon 2.8 computer to do some heavy mathematical analysis type stuff. (I'm hoping of using it for games). I know about the 2.4C and all, I've told him. Saving money doesn't seem to matter that much to him.

I know Xeons are used for the server/workstation market. P4's, while some have hyperthreading, are more meant for home use.


My dad is just curious what's the physical difference between the two...what makes the Xeon 3.06 533mhz fsb twice as expensive as the P4 3.06 533mhz fsb? I think he said he remember hearing somewhere that P4's are just Xeons with some disabled features, but that doesn't make much sense. I've heard some info, that Xeon's have more L3 cache.

Thanks.

 

[Optimist]

I'll go out on a limb here and let someone correct me. In terms of cost (to Intel) I don't think there is much difference between the two CPUs. But what matters is that, unlike AMD, you have to have the Xeons to run in a multiple processor setup (although a single Xeon will run alone).

Heh, I have a question for the experts. I never here the newer Xeons called P4 Xeons like the older ones were called P3 Xeons. Why not? Have I really misunderstood the technology?

 

[TerryMathews]

Some Xeons have more cache. The big selling point, however, is that the Xeons support multiple processors. They have two CPU_ID pins, allowing for a total of four processors on one northbridge, whereas the P4 has no CPU_ID pins, so it can only be a uniprocessor platform.

Aside from that, not much. As I understand it, the Xeon has no extra instructions. So, if your dad is not building a dually, or buying a chip with more cache, he's just throwing money away.

 

[smahoney]

With the release of the Pentium 4, Intel decided for several marketing related reasons to change the naming of the Xeon series from "Pentium X Xeon" to just Xeon. This was a move geared to the diverging technologies that will be used in future Xeon designs and the introduction of the Xeon MP processor with its L3 cache and the Xeon DP for dual processor configurations.

From a technical perspective the Xeon DP with 533MHz bus at 3.06 is very close to the P4 3.06 533MHz FSB chip. Outside of Dual Processor capability there is almost no known specific difference between the two other than the ability of the Xeon to address more than 4GB of RAM in very specific circumstances that require OS and Application support (Windows 2000 Advanced Server with Exchange 2000 or SQL Server will address 8GB of memory with a Xeon CPU and Intel memory extensions) - This will start to change with the Prescott releases. The Xeons are set to only go to a 667MHz FSB and not the 800MHz FSB. There are rumors of a larger L2 cache for the Prescott version of the Xeon but that hasn't been confirmed.

The Xeon MP for four or more CPU systems has a completely different pinout than the Xeon DP and an Integrated L3 cache and runs at a slower FSB adn has an integrated L3 cache with as much as 2MB of cache.