I also use an Addonics mSATA 4 bay card with a single Samsung 850EVO hard drive and I am able to get over 460MB/s in R/W on that drive. I use a Sonnet Tempo SSD Pro card with Intel DC S3500 600GB hard drives in RAID mode and get speeds close to 850MB/s. 4°) connected to an added PCI card : depending on the cards, you can achieve up to 450MB/s for a single drive, and up to 900MB/s for 2 SSD's in RAID 0 mode. 3°) using the external port, but those are really limited : 480mbps for the USB 2.0 ports (60MB/s max, but more about 35-40MB/s real) or FireWire800 (about 100MB/s max, about 65 - 75 MB/s real) In real life, you can depend on about 250 - 280 MB/s. Maximum available speed is about 370 MB/s, but again : that's theory. 2°) in one of the 4 dedicated HDD bays : those have each a 3gbps SATA bus. That means you'll have a maximum of 180MB/s theoritiacal speed, which means a real life speed of about 130Mb/s. 1°) as a replacement in the optical drive bays : those are on a 1,5gbps SATA bus.

So there are several ways you can have your SSD : Even if you do not mention it, I assume you have a Silver Mac Pro, and not the black round one.

Apple mac mini mid 2010 write speed