Two Mint 19.3 Aspires Suffer Near Useless Outgoing Data Transfer Speeds
Both Aspires -- Z1620-UR31P and E1-731-4651 -- are exclusively Linux Mint. Despite being two model years apart with different Intel processors, cards, and internal parts, both have become nearly useless transferring files to connected devices. Since at least Mint 19.2 my numerous USB 3.0 flash drives and two extreme transfer SD cards rarely receive data beyond 12 MBps, and are usually below 8 MBps. Putting that in perspective, it's taken 59 minutes to transfer 20GB to a USB 3.0 flash drive. Sending back to the Aspires brings normal USB 3.0 speeds around 640 MBps and roughly 170 MBps for the cards. Until now, my nearly one year with Mint has been delightfully flawless. But this sudden fault may well force me to dual-boot another Linux distribution. First, however, I'm seeking help finding some common denominator between two fairly different specification Aspires.
For now, I've refrained from such desperate fix attempts as a clean install of 19.3 or trying:
Path: /etc/default
Line to be added: iommu=soft
I'm well familiar with such commands as lsusb -t and lspci -v, but I'm dealing here with two very different external device types. One works through USB connection, the other directly through circuit boards. So rather than share numerous and likely pointless command results, I'm starting with the simple question: where might I begin looking for that "common denominator" among a maze of factors? Although I suspect my problem is a Mint 19 series issue, not an ACER one, I'm perplexed that I'm not finding others here with the same or a similar output-only transfer speed collapse.
