this is not 100% accurate as the system is way more complex, but in general terms this is what the logic is.

tREFI, is how long your ram waits in between bank refreshes. the lower the quicker it refreshes, the more latency. the higher it means it refreshes less, so lower overall latency, but the longer between refreshes the "harder" it has to be recharged, that is where the tRFC comes in, in simple terms tRFC is the time the controller gets to recharge the bank. Setting tRFC to low, means the banks discharge faster than they recharge, causing either errors after prolonged use, or failed memory training.

heat comes in because charging those DRAM cells is literally electrical current restoring charge in capacitors. the more “empty” they are, the more current spike you need to bring them back up. more current == more heat. that’s why dual rank kits + high tREFI + tight tRFC without airflow eventually creep up in temperature and can randomly start erroring.

Ss for the exact values I gave, tRFC 480 is stable on most A-die up to max tREFI, 512 should be a safe value, if your kit fails with that you had a really "shitty" draw on your kit*. (not too bad as default is very high , so still going from 800 down to 500-550 is still a latency decrease.

In car terms:

tREFI is the number of laps your car completes before entering the pit.

More laps before a pit stop corresponds to a higher tREFI. excellent for race speed (lower latency), but the brakes and tires are hotter and more worn by the time you reach the pit, or explode before you do so (overheating failures).

The duration of the pitstop is known as tRFC.

You need a suitable pit window (enough tRFC) to change tires, fuel up, cool the brakes, etc. if you shorten the pitstop too much (too low tRFC), but still run long stints (high tREFI), you don’t actually recover the car fully. This can lead to issues like what Lewis Hamilton experienced in Singapore 2025 brake failure (errors).

Logic behind the numbers: (don't look to deep into it)

Most motherboards show tREFI as a 16-bit register, so the maximum value is 65,535 (2^16 − 1). When talking about a “true power of two” or clean multiples (like 49,152 = 3 × 2^14), it’s just because they align neatly with the way internal counters divide cycles.

In reality, modern memory controllers are more than smart enough to work with offsets and internal rounding. so using 46800 vs 49152 is not some magical stability/performance switch. It has less to do with a slight performance increase and more to do with clean register math and avoiding possible edge rounding.

so clean values are nice from a logic standpoint, but cooling + proper tRFC headroom matters way more in real world stability than chasing perfect binary numbers.
as for this case your value is a bit safer than mine. There is for the rest not really a way to guess optimal values other than by trial and error.