Late 2009 iMac 21." External SSD very very slow
I recently purchased a Samsung T5 500GB SSD, to use as an external startup, running High Sierra, but didn't notice any boot up speed gain, ran Black Magic and the results are poor, see attached, I ran Black Magic on the HDD just to check and results were as expected (good for the HDD), so tested the T5 on my MacBook Pro and the results were optimal, is there something I'm missing on my iMac setup ??