As far as ASRock is concerned, there’s a significant difference in RAM support depending on whether you’re fitting a 200K or non-K Core Ultra. On the Z890 Taichi, processors that don’t support overclocking get less memory support!
Z890 Taichi: 7200 MT/s DDR5 only for non-K Core Ultra 200!
As you can see from the QVL (Qualified Vendor List) for the card in question, there is a significant difference in RAM speeds depending on the type of processor. For example, if you have an overclockable Core Ultra 200, a K model, you’ll find memory kits that can reach 9066 MT/s. In contrast, with a non-overclockable processor, a non-K model, RAM speed support drops to 7200 MT/s.
While the difference between the two types of processor is significant, it shouldn’t be too noticeable for the user. In fact, unless you’re using your PC in a very specific context where memory frequency plays a crucial role, the sweet spot in terms of memory frequency is around 6000 MT/s, since this is where you’ll find the best performance/price ratio in terms of RAM.
It’s also worth remembering that this type of top-of-the-range boards is generally used fornoverclocking, with a number of dedicated features. Logically, this is not the type of board that is intended for non-K processors. In fact, for your information, the Z890 Taichi OCF offers an even greater difference between Ultra K and non-K Core: 9600 MT/s vs. 7200 MT/s.