Is the stepping number match necessary for dual Xeon E5-2650 v4 on a SuperMicro X10DAX?

[Xstep2]

I bought a SuperMicro X10DAX in 2017 and have been running it with one CPU. I would like to add the 2nd CPU, there are plenty on ebay but none of them list the stepping number in their description. I vaguely remember dual CPUs have to match stepping numbers to be compatible but I couldn't find any reference to a stepping number in the X10DAX manual. I spent some time on the intel website and can't find a for sure answer in the massive amount of information. 

If this stepping number is important why wouldn't information about it be documented and clear?

I have an Intel Xeon E5-2650 v4 ~ ES QHV6 ~ { CPU STEPPING = 0 } { CPU Family = 6 } { CPU model = 4F }

[n_scott_pearson]

ES QHV6? That's an engineering sample. You shouldn't be using it for anything critical. ES processors will have errata that are not necessarily corrected by available microcode updates. As well, once they go production, many BIOS do not install microcode updates for ES (or PP) processors.

Find a processor that is compatible with your motherboard and purchase two of them.

...S

P.S. In the future, these kinds of queries may better be placed in the Servers forum. You will get a more-appropriate mindset for server-specific issues there.

[Xstep2]

Everything seems to have been working rock solid since 2017. Is there anything else I should be concerned about? I'm not sure what microcode updates would do. Is that a security issue or is it more like drivers or a bios where an upgrade would only be necessary for new features? I've been looking at replacing the processor{s} with one or two of the higher end Intel Xeon Processor E5 Family CPUs but still have the problem of is it better to upgrade to Supermicro X11 LGA3647 or invest and max out the older equipment.  Either way, I would still like to know where to find information about dual CPU compatibility requirements, if there are any, so I guess I will post this again on the server fourm.

[n_scott_pearson]

Microcode updates address errata in the processor. This may be fixes for errata in previous microcode versions or workarounds for errata in the silicon. Without these updates, errata remain exposed and hitting any of these errata will yield aberrant behaviour. You may get lucky and never have this happen. I still consider it to be a ticking time bomb.

Whether or not you want to take a chance with older or default microcode, I would only do so in a single-processor configuration. If you are thinking about using a dual-processor configuration, I still recommend replacing this ES process in the process.

...S

[Xstep2]

Well, I think I may have been been lucky but why double those chances, right, bombs are bad. It's still pretty weird that it's hard to find information about dual CPU compatibility.