Memory CAS latency question

[JoaoPires95]

Hello, and thank you in advance! I have an ASRock B350M motherboard, ryzen 1200 processor and 2400mhz CL15 G.skill aegis 2x4gb kit of memory. When I set the 2400 XMP profile the CAS latency is 15 in my bios but when I bump the ram voltage and the XMP profile to something higher than 2400, for example XMP 2800 @ 1.35V the CAS latency goes from 15 to 16 without me touching it and I can't seem to understand why. If I try to change it back it just ignores it and boots CL16 anyways. Can you help me figure it out? Thank you again!

[stealth80]

5 minutes ago, JoaoPires95 said:

Hello, and thank you in advance! I have an ASRock B350M motherboard, ryzen 1200 processor and 2400mhz CL15 G.skill aegis 2x4gb kit of memory. When I set the 2400 XMP profile the CAS latency is 15 in my bios but when I bump the ram voltage and the XMP profile to something higher than 2400, for example XMP 2800 @ 1.35V the CAS latency goes from 15 to 16 without me touching it and I can't seem to understand why. If I try to change it back it just ignores it and boots CL16 anyways. Can you help me figure it out? Thank you again!

its normal - the ram is rated 2400mhz @ CAS 15, if you increase the speed it will loosen timings to achieve the speed

[JoaoPires95]

10 minutes ago, stealth80 said:

its normal - the ram is rated 2400mhz @ CAS 15, if you increase the speed it will loosen timings to achieve the speed

Thank you for your awnser! But am I not supposed to be able to tighten the timings if I feel like it, even with the faster speeds?

[stealth80]

11 minutes ago, JoaoPires95 said:

Thank you for your awnser! But am I not supposed to be able to tighten the timings if I feel like it, even with the faster speeds?

no because you used XMP, the timings are set from a defined table stored on the memory itself. If you want to adjust timings then you need to go into manual ram overclocking, manually set the speed then set the timings manually

[JoaoPires95]

1 hour ago, stealth80 said:

no because you used XMP, the timings are set from a defined table stored on the memory itself. If you want to adjust timings then you need to go into manual ram overclocking, manually set the speed then set the timings manually

I tried manually overclocking with ryzen master software and the CAS latency also changes automatically from 15 to 16 whenever I go past 2400mhz speed. I set it to 2666 CL15, it asks me to reboot and when it does so I open Ryzen Master again and it's set to 16. Really odd.. any solution? Thank you!

[stealth80]

50 minutes ago, JoaoPires95 said:

I tried manually overclocking with ryzen master software and the CAS latency also changes automatically from 15 to 16 whenever I go past 2400mhz speed. I set it to 2666 CL15, it asks me to reboot and when it does so I open Ryzen Master again and it's set to 16. Really odd.. any solution? Thank you!

you need to do memory overclocking in the bios