Poor Choice RAM?

[Cloudy]

I plan on buying a Ryzen 9900X3D when it comes out, and will be my first AMD CPU. To go with it I bought a 2x16GB TeamGroup T-Force Delta RAM kit, but I am worried about the speed not being "1:1". It is 6400MHz 32CL 32-39-39-84, but many seem to say you should go with 6000MHz instead. Any tips for me? I know there is some luck with the quality of the CPU and what motherboard you run, but I need a video or someone to explain what I should be setting aside from unrelated PBO settings. I have learned so much about overclocking Intel chips, but I really want to learn the ins and outs of Ryzen CPUs.

[Rumpelcrutchskin]

It`s ok. Latency is still good on it and it`s not too high MHz where it could be unstable with certain motherboards. Generally sweet spot for AMD PC is 6000 MHz CL 30.

[A&A]

That "1:1" ratio on Zen 4 and 5 is dead. If you mean infinity fabric:Memory clock speed

[Cloudy]

A&A lähetti viestin:

That "1:1" ratio on Zen 4 and 5 is dead. If you mean infinity fabric:Memory clock speed

So should I be setting the Infinity Fabric Frequency to 2133MHz (1:3 of 6400MHz)
I also saw someone saying setting the tREF setting in Advanced Timing section to 65535... Does that only apply to people who are adjusting all their sub timings manually?

[A&A]

The memory clock speed is half of MT/s as it is DDR. This makes it 3200 MHz.

Infinity fabric default on Zen 5 I think is 2100MHz

Which means it is closer to 2:3 (21/31). Also the memory controller in the infinity fabric has 32b/cycle, while the single CCD is 48b/cycle, which is 3:2. So it's very close like the old school 1:1 ratio in Zen 2 and 3. The difference is that they force the RAM modules to run at higher frequencies.

tREF depends on the dies, so I wouldn't copy and paste bliendly. Even the modules themself can make a change.

[C1REX]

Cloudy lähetti viestin:

I plan on buying a Ryzen 9900X3D when it comes out, and will be my first AMD CPU. To go with it I bought a 2x16GB TeamGroup T-Force Delta RAM kit, but I am worried about the speed not being "1:1". It is 6400MHz 32CL 32-39-39-84, but many seem to say you should go with 6000MHz instead. Any tips for me? I know there is some luck with the quality of the CPU and what motherboard you run, but I need a video or someone to explain what I should be setting aside from unrelated PBO settings. I have learned so much about overclocking Intel chips, but I really want to learn the ins and outs of Ryzen CPUs.

If you lucky then it will work 1:1 with UCLK at 3200. Depends of silicone lottery and motherboard. If not then you can try to manually set to 6000 CL30 (still need a tiny bit of luck as it's not guaranteed).
Not sure about the best video. Buildzoid is probably the best.
https://www.youtube.com/watch?v=kRj7PfWBjUY

Or this guy that talks like a normal person
https://www.youtube.com/watch?v=mYu8s5BCvHI

I personally hate manual RAM tuning so I went with 6000 CL30.
Good news is that 3D chips don't care much about RAM speed. Opposite to non 3D chips that are very sensitive to memory speeds.

[De Hollandse Ezel]

I would not worry about it not being 1:1

I always only care about true latency.

for ddr basicly that is :
(speed/2) / latency
-
so 2800mhz cl14 is exactly equally fast as 8000mhz cl40

the issue now is.. this
-amd chips not always accept higher than 6000mhz speeds.
as it you turn on xmp profile for them.. and system won't boot/crashes

SOME amd chips have known to run stable with 6400mhz (silicon lottery winners) but it is not guaranteed you have one of those.

that said... 9800x3d might have a slighly better chance to work with 6400mhz if you also use the newer X870 and X870E chipsets it should be no issue)

now what will happen if you are unlucky.. well 2 things..
first you will have to turn off xmp.. causing your ram to run much slower
than you manually will have to set volage, mhz and latencies.. to something higher than that but lower than it's xmp profile.. until you reach the best it can run stable..
-
(easiest do do is just write down and enter all values of the xmp profile and only lower mhz to 6000)

this is ofcourse a hassle.. more work than just turn on xmp and be done.
but you also not likely to lower the cl quite as much even if you lower the mhz..
ram is easier to overclock or underclock at different mhz.. but tend to not like run at different latencies than it's made for very much (not say it cannot be done.. just less flexible there)

so than you end up having to run it at 6000mhz but with the same 32cl.
which would make it slower than stock 6000mhz cl30 memory.

it is for that reason + to not have to set timings manuall why not going over 6000mhz is advised.

[_I_]

6400 cl32 is fine, but not all cpus can hit that speed, and even fewer with 4 dimms
but the ram should have a xmp/spd profile for 3000 cl30 that it can fall back to

[Magma Dragoon]

I would stick to 6000 1:1

[smokerob79]

if you already bought it you can run 6000mhz with it but you will have to set the speeds.....6000 is the sweet spot.....

[Cloudy]

De Hollandse Ezel lähetti viestin:

9800x3d might have a slighly better chance to work with 6400mhz if you also use the newer X870 and X870E chipsets it should be no issue)

Because I found an insanely good price I went with an Asus TUF GAMING X670E-PLUS WIFI motherboard

[Cloudy]

_I_ lähetti viestin:

6400 cl32 is fine, but not all cpus can hit that speed, and even fewer with 4 dimms
but the ram should have a xmp/spd profile for 3000 cl30 that it can fall back to

Is it possible if it doesn't work at first I can get it working at 6400MHz 32CL by bumping up the DRAM voltage? It will be 2 DIMM thankfully.

[_I_]

its the cpus memory controller that would need the voltage bump, the ram is ok with the voltage set by xmp/spd profile

[Cloudy]

_I_ lähetti viestin:

its the cpus memory controller that would need the voltage bump, the ram is ok with the voltage set by xmp/spd profile

Noted, thank you