6,1 CPU upgrade - es

[p.l]

hi guys
Looking to upgrade my 6,1 to a 12 core.
Looking at a ES version to save some coin obviously not sure which version.

Would this work? http://www.ebay.com.au/ulk/itm/351618687525

I was looking at cpuworld and it has the same stepping as the SR version.

Would any version work or does it need to have the same stepping?

Thanks for any help in advance

 

[jetjaguar]

Here is the owc blog post where they list all the cpu upgrades

http://blog.macsales.com/22230-owcs-mac-pro-2013-processor-upgrade-compatibility-testing