Drive performance is dependent upon platter diameter, areal density and rpm. A 5400 rpm drive with an areal density 1.33 times that of an older one will deliver the same theoretical transfer rate as a older 7200 rom or even 10,000 rpm drive. Same for 2.5 versus 3.5" drives....the speed of the 3.5" drive at the outer edge is almost twice that of a a 2.5" drive.
A 2018 drive might be expected to have an areal density of 1,100 GB / in ^2 One from 2016 would have an expected areal density of 800,000 .... so:
1,100 x 5.4k rpm = 5,940 ... newer, slower rpm drive could deliver data slightly faster than older higher rpm drive
800 x 7.2k rpm = 5,760
Now that's based upon the state of current technology and what's possible .... drive manufacturers are not necessarily jumping on setting up new HD designs everytime available technology gets bumped and areal density info is oft hard to some by. Also what's being offered for sale deoends more upon user impact than "benchmarks" ... if a storage subsyetem's ability to deliver data is greater than the user's ability to manipulate it, then it's basically useless. We have seen this in the laptop market where performance of 2.5" drives have recently (last 2-3 years) been dropped to 5400 rpm for power savings which mean more to the portable user who is not sacrificing expected performance compared to older 7200 rpm drives because the newer drives deliver higher areal density.
Guys, is it a good idea to get one of those 64GB Kingstone ssd's & install the OS on it ??
No. We've never installed less than 120 GB and most of thoise come back with users asking to "Clean up C cause it's full".
Due storage manufacturer's decision in the 1990s to artificially inflate drive size by redefining a GB to 1,000 MBs instead of the real 1,024, that 64 GB only fits 59.5 GB of files..... leaving the recommended 15% free to maintain performance and reliability, you're left with only 50.5 GB of space. Do not recommend anything less than 250 / 256 GB
BTW, regarding the initial post, when you say "connected", we talking internal SATA or external eSATA ?