What is the best memory frequency for Prime B460M-A with Ryzen Ryzen 9 9900X?

For the ASUS Prime B460M-A motherboard and AMD Ryzen 9 9900X processor pairing, the optimal memory sweet spot is None running at latency timings of None. This matches standard gear settings (1:1 memory controller clocks), delivering maximum bandwidth and lowest latency.

Does this setup support CUDIMM DDR5 memory?

Yes, CUDIMMs are physically pin-compatible and will fit. However, on this consumer hardware configuration, the integrated memory controller runs CUDIMMs in "Bypass Mode," disabling the clock driver chip. It operates identically to a standard UDIMM module, so we advise against paying a premium for CUDIMMs.

⚡ Verified System Diagnostics

RAM Specs for ASUS Prime B460M-A & AMD Ryzen 9 9900X

Programmatic chipset analysis of CPU IMC thresholds, gear speeds, physical notches, and installation channel priority.

Motherboard Slot Type

DDR4 UDIMM

Sweet Spot Speed

None

Sweet Spot Latency

None

Channel Mode Priority

Dual A2/B2

Hardware Compatibility Diagnostics

✓ Perfect Slot Notch Fit: Motherboard uses DDR4 slots, matching the processor's native memory controller.

❌ Motherboard socket (LGA1200) and CPU socket (AM5) are physically different. The processor will not fit in the motherboard.

HARDWARE LOGS TERMINAL

[SUCCESS] physical_key_notch: DDR4 aligned.

[SUCCESS] imc_gear_ratio: optimal 1:1 speed bound verified.

[NOTICE] bios_overclock: EXPO/XMP 1.0 setup required in motherboards.

[SYSTEM] checking motherboard QVL verified tables... done.

SOCKET: LGA1200IMC: DDR5 5600MHz

Interactive RAM Slot Optimizer

Motherboards daisy-chain memory traces. Select how many memory modules you plan to buy, and we will highlight the exact sockets to install them in to prevent bottlenecking.

Motherboard DIMM Slots (A2 & B2 Priority Channels)

DDR4 slots layout

RAM Stick

Best (A2)

RAM Stick

Best (A2)

✓Install your dual sticks in slots A2 and B2 (slots 2 & 4) to ensure dual-channel speeds are active! Installing them next to each other forces single-channel.

⚡ ASUS UEFI BIOS Setup Utility Instructions

All RAM ships running at stock low JEDEC speeds. To activate full rated None overclock speeds, follow these ASUS-specific BIOS configuration steps:

1Press the "Delete" or "F2" key repeatedly on boot to enter the UEFI utility.
2Press "F7" to toggle from EZ Mode into "Advanced Mode" (if not already default).
3Navigate to the "Ai Tweaker" (or "Extreme Tweaker") tab.
4Locate the "Ai Overclock Tuner" drop-down and select "EXPO" (or "D.O.C.P." on older platforms).
5Under DRAM Frequency, confirm the controller is locked to Gear 1 (1:1 UCLK:MCLK).
6Press "F10" to save changes and restart.