If you look at the majority of 2008-2010 Macs, you then step down to SATA II and 3 Gb/s data rates and max out at 800 Mb/s data rates for external devices with FireWire-800 ports. In most Macs of this vintage, you’re looking at Thunderbolt 1 as your best option for external devices (in 20 Macs) and are thus limited to bi-directional 10 Gb/s, which indeed is nearly double the 6 Gb/s offered by SATA III and these Sandy Bridge and Ivy Bridge Macs. Many are getting long in the tooth and have limited external upgrade potential or simply can’t even keep up with the best options offered today in terms of approaching optimal throughput for external graphics (also known as eGPU) or getting the most out of blazing fast NVMe storage. Imagine the average 8-12 year old Mac sitting on your desk today. Expansion and I/O Challenges with Older Macs
