Also after updating the dbcache setting still ridiculously slow like .09% per hour. Like 10 times too slow.
That new setting is fine.
Setting the database cache to 16GB while having 8GB of RAM is bad for your SSD since your system will be relying too much on page file.
Bitcoin Core use almost all of the allotted dbcache (
about 15GB with your previous setting) to save the UTXO set to RAM before writing it on disk.
Since more than half is being moved from/to disk as page file, plus the data being dumped to the data directory,
your SSD must had been on a lot of strain before that could make IBD slower. (
apparent on HDD, not much on SSD)
How about your peers?
try: bitcoin-cli getpeerinfois it populated with nodes with bad connections? Peers keep disconnecting?