WOW, I had no idea that the external Thunderbolt 1 speed was faster than the internal SATA speeds of the Mac Mini mid2011... I just assumed that because Thunderbolt 1 was external it would be slower than the internal SATA speeds.
Can anyone please confirm this? I've been looking online for an article but I can't find anything comparing speeds of an external HDD connected via Thunderbolt 1 and an internal HDD connected to the Mac Mini mid2011's SATA cable?
I do own a Mac Mini 2011 connected to a FireWire 800 hard drive and a Thunderbolt 1/2 hub that connect to a USB 3 USAP hard drive NexSTAR dock which roughly gives me 6Gbps xfer speeds out 10.
On the Mac Mini 2011 with an internal Kingston 240Gb SSD = 226MB/s read and 100MB/s write
On the Mac Mini 2011 with a Firewire 800 5400RPM hard drive = 60MB/s read and 55MB/s write
On the Mac Mini 2011 with a Thunderbolt hub connected to 7200RPM drive = 100MB/s read and 100MB/s write
On the Mac Mini 2011 with a Thunderbolt hub connected to 480GB SSD USB USAP = 480MB/s read and 400MB/s write
So all in all, an SSD drive connected to a Thunderbolt hub on the Mac Mini 2011 smokes not only the internal SSD, but also anything else that could connect to the 2011 Mini.
I multi-boot this Mini 2011 as it is my network server for all my Macs, PCs and Linux machines, and because the StarTech Thunderbolt Hub also comes with an extra Gigabit ethernet and HDMI port, I use the Gigabit ethernet to connect to my PowerMac G5 as my secondary server to the Mini. Anything through Thunderbolt is just super fast and great, including ethernet which doesn't seemed to be slowed down by any major activities while the Mini 2011 is serving other computers!
If you are going to go the Thunderbolt route, I suggest that you get a Startech hub. I got one pretty cheap from a recycling place where I worked, only $10, but usually retails around $80 used. They are much more expensive when you buy them new, but now they shouldn't be because Thunderbolt 1/2 are obsolete. Thunderbolt 3 and soon 4 are current. Getting a hub gives you multiple USB 3 ports which makes the Mini 2011 almost like the Mini 2012. USB 3 with USAP is fast enough for boot and write as you could see with my SSD connected to the Thunderbolt HUB. Even my Mac Pro with the Caldigit 3 PRO esata and USB3 PCIe card couldn't match its speeds compared to my Mini 2011 with Thunderbolt. So yes, Thunderbolt is fast.
Hope this helps.