Why chose Xeon® E5-2643 over i7-2600K

Why would someone chose a Xeon e5-2643 @ $885 over a i7-2600K @ $300 when the i7 has a higher passmark rating?
LVL 86
David Johnson, CD, MVPOwnerAsked:
Who is Participating?
Gary CaseConnect With a Mentor RetiredCommented:
Well ... first, the Passmark ratings are close enough that there's not going to be an appreciable performance difference  (8271 vs 9073).

The Xeon's are much more "industrial strength" CPUs => designed for far more memory, with a much more reliable memory subsystem using registered ECC modules instead of the unbuffered RAM used in desktop boards.    For example, the E5-2643 supports up to 750GB of RAM at a bandwidth of 51.2GB/s with 4 memory channels;   compared to a maximum of 32GB of RAM with a bandwidth of 21GB/s and only 2 memory channels for the 2600K.    And a 2600K with 4 installed modules will be much less reliable than any number of installed modules on a Xeon using registered modules.

There are other features that server-quality motherboards have as well -- notably better system management and monitoring features that you likely won't use if you're simply building a desktop system.

Another consideration is that motherboards that support the E5-2643 will also support the 8-core E5 series Xeons -- e.g. the E5-2650/60/70s ... the E5-2670 scores 15565 on Passmark.    So there's an easy upgrade path to even more performance.

Bottom line:   Given a choice, I'd always use registered modules instead of unbuffered RAM.   However, due to the cost factors, I generally recommend the following:   If you're happy with the amount of RAM that one module/channel will provide, it's fine to use a desktop board with unbuffered modules.     For this question, that would be 16GB of RAM with the 2600K  (using 2  8GB modules).    If you want more memory, consider using a server board that supports registered RAM, or build an X79 based system with quad channel memory and use 4  8GB modules to get 32GB.    If you really want to install 2 modules/channel, at least buy a board with ECC support and use ECC modules -- an unbuffered ECC module isn't nearly as good as using buffered modules;  but at least it will self-correct single-bit errors.
Brad BouchardInformation Systems Security OfficerCommented:
Because the Xeon is designed for a server vs the i7 which is designed for desktops and their voltage.  The voltage as well as the load of the Xeon will hold up longer in the end.  There are also heat issues to consider when you think of Xeons.
David Johnson, CD, MVPOwnerAuthor Commented:
They are both 95W TDP products? Xeon's run hotter? I still can't see why I'd pay 3x the price for about 2/3rds the passmark performance? I must be really missing something here.. They are both sandybridge processors... I can't see paying $600 for the word XEON..
Gary CaseRetiredCommented:
"... They are both 95W TDP products? "  ==>  No, the E5-2643 is a 130w TDP CPU.    Interestingly, it's 8-core "big brothers" are lower power units -- the E5-2650 & 2660 are 95W, and the 2670 is 115W.

Also, the PassMark is a lot more than "2/3rds the performance ==>  8271/9073 ~ 92%

You're not just paying for the word "Xeon" :-)     I agree that for a desktop system with no more than 16GB of RAM a good 1155 board and a 2600K is a great choice.    But for the reasons I noted above, there ARE times when you want to be a more robust system that can handle a lot more memory -- THAT is what you're paying for when you use Xeon-based hardware.
David Johnson, CD, MVPOwnerAuthor Commented:
This all started me thinking when I was looking at a question about an hp workstation in the 2-3K range and when I looked at the build out and started comparing specs I was totally lost at the apparently extremely high price of these workstations, a desktop with much better hardware could be built for $1,500.. Thanks for the enlightenment.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.