Back in June, we covered the issue plaguing the Western Digital Black SN850 solid state drive, one of the best SSDs out there right now. Fortunately for users, Western Digital has just released a new firmware update that ought to rectify the performance issues the WD SN850 users were experiencing.
In case you missed it, the issue was specific to users pairing the WD SN850 with an AMD X570 motherboard. Despite having been rated for sequential read speeds up to 7000MB/s and sequential write speeds up to 5300MB/s, performance tanks by up to 40% when used on a secondary M.2 slot on an AMD X570 motherboard.
According to Western Digital, the issue appears to be related to the PCIe maximum payload size, a setting that determines the amount of data each data packet transmits through your system. The older SN850 firmware (version 61300WD) seems to have been bottlenecked by a low MPS of just 128 bytes when connected to the X570 chipset’s PCIe lanes. Their new firmware update (version 613200WD) for the SN850 however fixes this, though they didn’t say exactly what was changed by them.
A user by the name of MichaelMros on the ComputerBase forums tested out the new firmware and found that it had indeed fixed the issue. When he connected his SN850 to his motherboard’s secondary M.2 slot, performance speeds improved back to expected levels, compared to the old firmware.
WD SN850 on the new firmware 
WD SN850 on the old firmware
Users of the SN850 SSD will be able to update their drive via the Western Digital Dashboard program. Simply install and open the app, and it should prompt you to update your drive’s firmware. If you don’t have Western Digital Dashboard installed, you can download the Western Digital Dashboard program from the WD SN850 support page.
