I have x570 mobo, Asus Crossfire VIII Hero ( non-wifi ) 3003 Bios, AMD latest shipset.
I have Samsung 980 PRO 500TB ( C: )
& also Samsung 930 PRO 1TB (D:)
I did all the troubleshooting I could for the 500GB deleting all trash and moving all big installs to the 1TB to see if its was an issue I found online of it 'being too full'.
Its slow 1000-1600 MB/s Write vs the 1TB is 5k+.
Both ports are Gen 4 PCIE.
Both have same firmware.
Both are nominal temps.
Do Samsung support folks review these boards?
Same issue here with a 500 GB 980 Pro as boot drive, Ryzen 9 3900X with latest chipset drivers on a ROG Strix B550-F. Don't even know if this will ever be fixed... a driver and firmware updates would be nice, Samsung...
FWIW, this topic has been discussed in certain places (one of them being the European equivalent of this web site). Here are some links to them:
In a nutshell, the primary problem appears to be related to the cache getting filled up (which causes the write speed to plummet) and taking a long time to get reset or flushed or cleared or [insert appropriate technical term here]. Some people report things clearing up after a bit of time leaving the system on but unused while others report it more-or-less never clearing itself up. Not sure what to make of it myself, since Samsung doesn't appear to be eager to address / explain the situation in an up-front manner.