with Big Sur, it’s over. Up through 10.15.7 Catalina, I would go into recovery mode on the Mac, and disable System Integrity Protection, by typing into terminal “csrutil disable” and reboot the Mac. Then I could load Sonnet Twin 10G and Promise SanLink2 drivers. But with the introduction of Big Sur 11.x, that no longer seems to work. Apple has become very very aggressive about not allowing old “obsolete” hardware to work – probably because they want you to buy a new Thunderbolt 3 computer ! (no crying about how your 2013 Mac Pro is still working perfectly fine – Apple won’t have your tears !). So the only thing that is working on the old T2 computers is the Sonnet Solo 10G T2, which is $199, (I think it just went up in price) – and you will get HALF the performance that you got on a Twin 10G or SanLink2 – because it’s buss powered, and a T2 port can’t supply enough power to allow it to run at full speed. For a Thunderbolt 3 computer – the SanLink3, Promise Solo 10G T3, or the QNAP QNA-T310G1T will work at full speed – and those are buss powered (but you are now on a new Thunderbolt 3 computer).
Listen Mel – you can’t win. You are going to have to buy new Apple computers. I don’t care if you don’t have the money. Tim Cook doesn’t give a damn if you and your family starve – he wants you to give him YOUR money, and buy a new computer. It’s 2021, and he needs a new helicopter !
either I was not clear (I often am not !) – or you did not understand my post. Those 3 products you list are for Thunderbolt 3 computers, not a 2013 6,1 Mac Pro that uses Thunderbolt 2. If you have Big Sur running on a 2013 6,1 Mac Pro, the ONLY product you can use is the Sonnet Solo 10G T2 (thunderbolt 2). You cannot use one of the T3 products, and stick a T3 to T2 adapter on it – there is no enough power on a T2 port to power any of these T3 adapters.
If you have new Thunderbolt 3 computers, I would recommend the QNAP QNA-T310TG1T for $183. It’s just plugs in and works on a Thunderbolt 3 Mac running Big Sur. No drivers to install. And you better start to realize that no matter how perfect your 2013 Mac Pro is – you better start thinking about the reality that you are at the end of the road with this product.