Originally Posted by os2wiz
So why are my 4 Flare X DDR4 3200 DIMMS now running slower at 2133 with bios 1.4 than the 2400mhz it ran at with 1.3 and all earlier bios versions?. I give zero veracity to the claim of 4 dimms running at 32000mhz. Especially since the claim was four 16GB dual ranked dimms on a Crosshair VI. I still doubt the Gigabyte users claim. It is totally inconsistent with what I have heard unless MSI has not developed their bios code properly. Something isn't right. I have seen or heard no such claims on the Titanium for 4 dimms. I would not be surprised if the claims on other boards are validated by others that MSI has once again fallen short with their bios team.
It's a lot more complicated than it used to be "back in the day".
Even though there are ony a handful of actual IC's used, as Mega Man had mentioned there are differences in the actual DIMMs. The DIMM store tables with recommended settings but those are based on the Intel memory architecture. What's the difference? I cannot say definitively, but line impedance, frequency, voltage, and trace length all have an impact. Mismatched impedance will cause signal reflections, trace differences impact signal transit times, etc.
AMD is modifying their code to correct for differences between the given DIMM data and their actual requirements (at least that is my understand of this). The latest update may by misreading your DIMMs identity or have a mistake in it's "translation". The BIOS has more controls enabled that we can manually set to override some of these values, such as impedance, but without technical specs it is all guesswork and a PITA.
I would suggest that if a BIOS updates makes things *worse* for you, that you submit a service ticket to make the manufacturer aware. Don't expect a "fix" as a response, but at least they pass it along to the dev team to look into.