“A small L3 hurts Renoir, but Van Gogh sees a special level of pain because LPDDR5 latency is abysmal. Even servers these days don’t take 150 ns to get data from memory.”
The Steam Deck’s chip has four Zen 2 cores, 4 MB of L3 and a shared 16 W budget. When the GPU runs flat out, the CPU drops to 2-3 W and phone-class clocks. Valve’s default Linux governor makes the L3 all but vanish in latency tests, while Windows shows it fine. Valve sells a gaming PC and ships power settings that hide its own cache.