Shortly: AMD and Valve are working on an improved Linux CPU driver that will improve frequency scaling on Zen-2 processors. This should give some more credibility to Valve's claim that the Steam Deck can achieve at least 30 frames per second in all modern games.
When Valve announced the Steam Deck last month, it caused a lot of excitement among gamers who'd been waiting to play their favorite games from their Steam library wherever they want without having to lug around a proper gaming laptop. Even Epic CEO Tim Sweeney thinks the idea is a great idea, but as always, execution is what ultimately decides whether or not it will be a success.
There has been a lot of speculation about how well the console will perform, and the specs are pretty impressive considering the size, at least on paper. Valve says the custom AMD APU paired with 16GB of LPDDR5 memory can hit at least 30 frames per second in pretty much every current AAA game, but the company hasn't elaborated on that.
We can only assume that the Steam Deck's RDNA 2 GPU is likely good enough to run games at low to medium settings on the 800p display (especially with the help of AMD's FidelityFX Super Resolution in games that support it), but the performance sought by Valve may also be the result of additional software optimization work.
According to a Phoronix report, Valve has teamed up with AMD to develop a better Linux driver for the Zen 2 CPU in the new console, which, among other things, should solve problems with scaling the CPU performance.
The main reason for this development effort is that the current ACPI CPUFreq driver is "not very performance / energy efficient (efficient)" for modern AMD platforms.
In other words, the new driver enables the processor in the Steam Deck to quickly boot up to a higher power state when needed and get better performance per watt. This is important because the power budget for both the CPU and GPU is relatively limited at 15W.
We'll hear more about AMD's new Linux CPU driver in September as the company is expected to reveal more details at the X.org Developer Conference (XDC).