Test: HDDs speed under USB 2.0 vs. USB 3.0 vs. SATAII

[Fli]

I was testing the speed of the HDD (this time it was Exos X16 ST16000NM001G-2KK103 16TB (https://ssd.userbenchmark.com/SpeedTest/893643/ST16000NM001G-2KK103)) under different interfaces.

First test is SATAII
second is USB 2.0 external HDD enclosure
third is USB 3.0 external HDD enclosure Axagon ADSA-ST, 2x SATA 6G connected to a USB 3.0 hub Axagon HUE-S2BPhttps://i.postimg.cc/MqNFtYFq/Exos-X16-16-TB-Crystal-Disk-Mark-SATA2-vs-USB2-0-Dock-vs-USB3-0-Dock-And-Hub.gif

just 2 tests per interface

LEGEND:
SEQ = simple writing or reading (important for the drive that is working with large files)
RND4K = random small 4KB "file" reading/writing (important for system drive with tiny small operations)
Q32T16 - 32 queues and 16 threads (multithreading)

HOW I READ THE TEST RESULT:
SATAII vs. USB 3.0: sequential speeds (SEQ) are the same. Interesting is the difference in random 4K values (RND4K), i am unsure if this is just erroneous test.
USB 3.0 vs. USB 2.0: sequential speeds (SEQ) are significantly different as expected, but the the single threaded random 4K values seems quite the same, but the multi threaded 4K is half or even slower for USB 2.0.

MY SUMMARY:
Best is SATA interface, though in my test USB 3.0 had higher random threaded 4K writing.510

[RuskinF]

Single hard drives (USB 2.0 or 3.0) don't even approach the maximum transfer rate of SATAII. You should look at the latency times.

But whatever you do, don't buy a prefab external hard drive. They almost always have slower drives than normal internal drives.