Is the Sonnet expansion card to get thunderbolt 3 outlets , non-thunderbolt 2012 running10.13.6compatible?

I suspect you are referring to one of the following cards -

https://www.sonnettech.com/product/allegro-usbc-pcie.html

https://www.sonnettech.com/product/allegro-usbc-4port-pcie.html

These are USB-C aka USB3.1 Gen 2 cards. They are not Thunderbolt3 cards.

Yes Thunderbolt3 uses the same USB-C type connector but a USB-C port can provide the following -

• Power
• USB
• DisplayPort
• Thunderbolt

It could supply all of these or just some of them. In the case of the above two cards it only provides Power and USB.

As indicated by Grant it is not possible to add Thunderbolt to a classic Mac Pro.

The other possible Sonnet card is this one -

https://www.amazon.co.uk/Sonnet-Thunderbolt-Upgrade-Card-Express/dp/B01MZ9YG8H/

This is a card for upgrading an external PCIe expansion chassis. The chassis would originally have had Thunderbolt2 and this card upgrades it to Thunderbolt3. Since the Mac the chassis would be connected would already have Thunderbolt and since the chassis would also already have Thunderbolt this is possible. Whereas a classic Mac Pro has never had Thunderbolt.

Note: There have been some reports of partial success by using a suitable Thunderbolt add-on card, booting via BootCamp in to Windows, loading a driver, and warm rebooting back in to macOS. See - https://www.pro-tools-expert.com/production-expert-1/2019/3/15/mac-pro-51-cheese-grater-with-thunderbolt-the-impossible-is-now-possible this approach is so limited as to be in the real world a complete waste of time. It does show that in theory it might be possible to get Thunderbolt working after a normal Mac boot but not so that it works during/before booting so it would not work for booting from an external Thunderbolt drive for example, not even in Windows via Boot Camp.

2012 Mac Pro model?

To use genuine ThunderBolt devices, a Mac must have left the factory at least ThunderBolt-capable, and in most cases with ThunderBolt ports installed. The Mac Pro 2102 silver tower is not a member of that club.

The card you are referencing is for a different purpose.

For more info on Thunderbolt 3 on a Mac Pro 5,1, see here. Basically its surrounded by asterisks as mentioned. It works with audio devices using a Gigabyte GC-TITAN RIDGE after first booting Windows 10, then booting OSX afterwards. There are audio guys who make a go out of this, but devices are not hot swappable.

http://blog.greggant.com/posts/2018/05/07/definitive-mac-pro-upgrade-guide.html#thunderbolt

Hi,

No, it's not compatible with Mac which doesn't have Thunderbolt ports.