I have performed a series of drive speed tests with different drives, different connection ports and I have been unable to replicate the reported improvement in performance with or without a Thunderbolt monitor. Tests were conducted using
Stibium from
The Eclectic Light Company (If you haven't checked them out they have an amazing number of useful free utilities.) Admittedly I could have run more trials in each configuration and there are innumerable other potential configurations that might have made a difference but here are my
test results. Contrary to the reported results that started this thread, the only performance improvement I found was a modest 10%
increase in the write speed by disconnecting the Thunderbolt Monitor which, of course, contradicts the findings reported in the article and seem more intuitive to me.
I was disappointed in the performance of one of my OWC drives and puzzled by the miserable performance of another when connected via a USB 3.1 gen 2 port. Note also that despite the reports of poor performance of HDs formatted APFS these tests found no significant difference. My belief is the USB 3.1 gen 2 port is the limiting factor not the disk format. I am adding a To Do to my list to check the connections and configuration of that particular hub. One final note: the performance of the Samsung Thunderbolt 3 SSD is exemplary (exceeding the theoretical max throughput of Thunderbolt 3 or 4) but under load if I used it as a coaster my coffee would be nicely warmed all day long — those drives do run hot. The enclosure is solid plastic and does not make a good heat sink where as the OWC SSDs have a metal enclosure which acts as a heat sink to keep them cool. I don't know what the long term implications of heat are on SSDs, but intuitively I am happier with the cooler drives.
