Changed cpu and now ram is unstable

Griff7520 · 4 Apr 2023 at 19:48

Just changed from a 12100f to a 13400f on my B660M-A Msi board and now my Ram will not run at 3600. Before the change The ram which is 8-pack team group 3200 cas 14 kit was happily running at 3600 with 16 timings, With the new cpu it will not run over the stock 3200 speeds. Any idea why the cpu will not run the ram as before. I also noticed in the timings in bios the tRCDW is reading as 0, any ideas whats happening here or is it just a case of getting a poor 13400 cpu

thanks

momo56 · 4 Apr 2023 at 20:19

Have you updated the bios and intel management engine drivers ? I remember this being an issue on release for z690 and 13th gen.

Griff7520 · 4 Apr 2023 at 20:23

all ready on latest bios and dont know about drivers.....not something i install....will do it and see if it helps

Griff7520 · 4 Apr 2023 at 20:39

tried to install drivers from website but it said the drivers I had all ready were newer...so had the latest afterall

Dg834man · 4 Apr 2023 at 21:54

Reset bios to factory defaults then enable xmp again

nutsnut · 4 Apr 2023 at 23:33

New CPU may have a poorer imc.

Griff7520 · 5 Apr 2023 at 01:57

nutsnut said:
New CPU may have a poorer imc.

think your right....managed to get it to 3400 cas16 17 17 17 and its running ok....but it wont do 3600.....so leaving it at that for now....

tamzzy · 5 Apr 2023 at 06:43

3200 c14 would probably give better performance than 3400 c16 no?

Griff7520 · 5 Apr 2023 at 10:54

the latency is higher but the reads/writes are a bit better at 3400

tamzzy · 5 Apr 2023 at 12:53

Griff7520 said:
the latency is higher but the reads/writes are a bit better at 3400

What you said is true. Depending on your use case though, the lower latency may be a bigger benefit than absolute throughput.

Griff7520 · 10 Apr 2023 at 12:20

after doing a bit of research on Youtube I found out that locked alderlake/Raptorlake cpus will not run 3600 speeds in gear1 but it will run in gear 2. I tried this and it is correct, managed to run at gear 2 at 3600 and it booted first time. Obviously the bandwidth was better but the latency went from 62 upto 80 from the 3400 speed. So i put in 3500 at gear 1 and again the pc booted first time and it is an improvement over 3400 in both bandwidth and latency so looks like its the sweet spot on this cpu. Hope the info helps.