RAM frequency always resets

[Zer0mavrick]

I recently bought 2 sticks  of t force xcalibur rgb ram that is rated for 4000mhz 18 20 20 44 at 1.35v. My gigabyte z390m gaming motherboard (also have i7 9700k) pretty much refuses to run anything over 3600mhz... it just always resets the ram to 3600 when using xmp. When going manual I can boot to windows but its NEVER stable no matter how much I change my SA and IO. I just get errors out of the wazoo.even though this board is rated up to 4233. I've been told it's due to it being t topology. So I've decided to just work with 3600 and tighten the timings, it's at 16 16 16 32 1t now, but I want to go lower, but the motherboard just drops the ram frequency to 3200 anytime I make changes past 16.. am I doing something wrong?

[Jurrunio]

3 minutes ago, Zer0mavrick said:

When going manual I can boot to windows but its NEVER stable no matter how much I change my SA and IO.

That's the reason, it's just not stable (tho usually motherboards load up the previous stable settings instead).

[porina]

Ram-CPU-mobo compatibility is never 100% once you go above the supported speed of any single part. The higher you go, the more risk there is it doesn't work together. Not a lot you can do about it, apart from run slower or try totally different ram.

 

Does the ram have multiple XMP profiles? I have Kingston HyperX 4000 ram with 3600 and 4000 profiles. Both seem to work, but in actual benchmarks in different workloads I get better performance from the 3600 profile. Maybe because of tighter timings. That applies to both Intel and AMD systems I tried it on.

[Zer0mavrick]

That's  what I said in my previous comment. I've been trying to tighten timings and use 3600mhz because xmp and manual dont work. That's why I asked why it changes my ram frequency to 3200 when i go beneath 16cl

[Zer0mavrick]

4 hours ago, Jurrunio said:

That's the reason, it's just not stable (tho usually motherboards load up the previous stable settings

Yeah but this doesnt do previous. Ut either just resets bios or down clocks my frequency 

[Jurrunio]

22 minutes ago, Zer0mavrick said:

Yeah but this doesnt do previous. Ut either just resets bios or down clocks my frequency 

well I guess now it does.

[-rascal-]

45 minutes ago, Zer0mavrick said:

That's  what I said in my previous comment. I've been trying to tighten timings and use 3600mhz because xmp and manual dont work. That's why I asked why it changes my ram frequency to 3200 when i go beneath 16cl

 

Ah yes, Gigabyte motherboard BIOS will do that.

My Z390 Aorus Master does that too.

 

Your memory kit is not stable below tCL=16.

You just need to live with tCL=16, or try another memory kit.

 

The board is rated UP TO DDR4-4233, but the RAM kit that you have, AND the quality of the Integrated Memory Controller (IMC) within your CPU are also factors. CPU IMC = Silicon Lottery.

 

It will try the timings you set, and then will go through a few attempts through the memory re-try / re-learn process.

If it fails, the motherboard will drop the Memory frequency down 1x or 2x (which can be 3000 / 3200 / 3400) so it can boot at least successfully boot into OS.

 

If you REALLY want to get your hands dirty into DRAM overclocking...

It's pretty thorough, and goes deeper than your usually primary timings; it goes into secondary + tertiary timings, etc.

https://github.com/integralfx/MemTestHelper/blob/master/DDR4 OC Guide.md