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Can I use two different e5 24xx on one dual socket motherboard or must the CPU's be identical?

HBruijn
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user3447070
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    Why downvoting a completely valid question? Not everyone knows if you can do this or not. – Petr Jun 19 '17 at 08:11

2 Answers2

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Just don't do this.

It doesn't matter what the silly reason or specific circumstance is... Either use one processor or two identical processors.

See: Is it possible to influence the way CPUs are enumerated under Linux?

and: Can I mix two cpus with a different clock speed on a board?

Community
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ewwhite
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    This really isn't as big a deal as you make it seem. Intel even documents this, and lists which CPUs support it: http://www.intel.com/content/www/us/en/processors/xeon/xeon-5500-vol-1-datasheet.html – zymhan Feb 26 '16 at 13:01
  • But there's no _good_ reason to do it. – ewwhite Feb 26 '16 at 13:02
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    No one asked if it was a good idea. They just asked if it was supported. And it is. – zymhan Feb 26 '16 at 13:03
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    I give you a good reason to do this: you have 2 different CPU's and you don't want to throw one of them to dustbin. – Petr Jun 19 '17 at 08:13
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    Has anything changed since 2014 by any chance? Are the new Scalable Xeons better for mixing different models of them? At least, the operational frequency and voltage seems to be adjustable as far as I can tell (SpeedStep feature). – user2173353 Mar 20 '20 at 12:42
  • @user2173353 Why would you want to do this? – ewwhite Mar 20 '20 at 16:01
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    @ewwhite Because you might buy a server model with only one CPU installed and then want to add a second CPU from an other model that isn't identical. Or because you don't have the budget to buy an identical CPU. It could be many things. It would be handy to not have to match the processor exactly. But if it causes so many problems, maybe it is not worth it. I was just wondering if anything had changed or is expected to change in those problems. Because, being able to mix processors without issues would be a nice feature, I think. – user2173353 Mar 23 '20 at 08:28
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Yes, you can. Intel says in their Xeon Datasheets that you only need to match the:

  • Intel QuickPath Interconnect frequency
  • core frequency
  • power segment
  • internal cache sizes.

Also, they state "Mixing components operating at different internal clock frequencies is not supported and will not be validated by Intel. Combining processors from different power segments is also not supported."

http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-1600-2600-vol-1-datasheet.html (page 165)

http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v3-datasheet-vol-1.html (page 28)

http://www.intel.com/content/www/us/en/processors/xeon/xeon-5500-vol-1-datasheet.html (page 25)

zymhan
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  • But why would anyone do this? You're overlooking the practicality, supportability and business reasons that argue against it. – ewwhite Feb 26 '16 at 15:23
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    @ewwhite I'm not overlooking those reasons, I'm just leaving them up to the reader to take into consideration. – zymhan Feb 26 '16 at 15:29