Getting 1:1 infinity fabric

[JackMaro]

Hi’ I’ve seached all over the web, about Ryzen 3000 and which RAM that works well with the the processor. I found this thing called “Infinity Fabric” which is some thing AMD uses to determine “the sweet spot” in terms of RAM frequency and Cas Latency as far as I’ve understood.

 

I saw this picture AMD released for their Ryzen 3000 series, where it said that the best price/performance spot was 3600MHz and CL16. 

 

 

So I went at bought these g.skill TridentZ neo DDR4 RAM (F4-3600C16D-32GTZNC) with CL16-19-19-39 1,35V. It specially says on the box, that they are “engineered to provide premium performance for the latest AMD Ryzen 3000 series on the X570 chipset platform”

 

 

 

I have a Ryzen 9 3900X CPU and Asus Rog Strix X570 F-Gaming MOBO.

 

NOW I’ve updated the BIOS and suddenly options appear, like FCLK frequency. But I don’t know what i should fiddle with, I don’t want to kill the electronics.

 

Under the tab “Ai Tweaker” (inside the bios)

 

• Memory Frequency is set to ‘Auto’ and it says the target DRAM (which I guess is RAM/Memory) frequency is ‘2133MHz’. I can in here (the BIOS) set the Memory Frequency to some values between ‘DDR4-1333MHz’ and ‘DDR4-6000MHz’ instead of ‘Auto’ (3600MHz is one of them).

 

• FCLK Frequency (which is something to do with infinity fabric I think) is set to ‘Auto’ as well, where the Target FCLK Frequency is ‘1200MHz’. Like the Memory Frequency can I instead of ‘Auto’ set some values. Here between 666MHz and 3000MHz.

 

• Target CPU speed is 3800Mhz (it has gone over 4,2 MHz, when using the computer though - I don’t know if it has something to do with “AI Overclock Tuner” or “Perfermance Enhancher” being set to ‘Auto’).

 

• It says DRAM voltage is 1.2V i don’t know if it has to be 1.35V as it says on the TridentZ neo box. But I can’t change it - it’s not an option to change ‘auto’.

 

Under a sub folder “Ai Tweaker\DRAM Timing Control”

 

• The DRAM CAS# Latency is 15CL and is set to ‘Auto’ - can’t change it.

 

I’ve noticed that Increasing the DRAM frequency to 3600MHz increase this to like 25CL or something. (Which is what I don’t understand, when the RAM says it can do 3600Mhz and CL16 - specifically for the Ryzen 3000 Series in order to get infinity fabric 1:1)

 

Don’t know if I have to check’ something, if I am to change these ‘auto’ values.

 

What should I do, in order to get maximum out out my RAM?

[.Apex.]

7 minutes ago, JackMaro said:

I’ve noticed that Increasing the DRAM frequency to 3600MHz increase this to like 25CL or something. (Which is what I don’t understand, when the RAM says it can do 3600Mhz and CL16 - specifically for the Ryzen 3000 Series in order to get infinity fabric 1:1)

You need to look for XMP/DOCP to get your RAM running at the advertised 3600Mhz CL16 speeds, and the infinity fabric should clock 1:1 automatically with the RAM as far as I know.

 

Since you have an ASUS board, the XMP/DOCP profiles should be in Easy Mode once you get into BIOS in the middle left.

[JackMaro]

3 minutes ago, _Syn_ said:

You need to look for XMP/DOCP to get your RAM running at the advertised 3600Mhz CL16 speeds, and the infinity fabric should clock 1:1 automatically with the RAM as far as I know.

Ok, i'll Quickly look at the BIOS, and try to find XMP or DOCP

[JackMaro]

6 minutes ago, JackMaro said:

Ok, i'll Quickly look at the BIOS, and try to find XMP or DOCP

Thanks so much! I couldn't find the XMP profile, because i didn't know about D.O.C.P. 

After googled a little bit, i found that D.O.C.P option was available under AI Overclock Tuner. After i set it to D.O.C.P, it notified me about FCLK and 1:1 and changed it all, so it was propper 1:1. Thanks!

 

[JackMaro]

23 minutes ago, _Syn_ said:

You need to look for XMP/DOCP to get your RAM running at the advertised 3600Mhz CL16 speeds, and the infinity fabric should clock 1:1 automatically with the RAM as far as I know.

 

Since you have an ASUS board, the XMP/DOCP profiles should be in Easy Mode once you get into BIOS in the middle left.

I guess, the NB Frenquency has to be doubled right? If so, then it should run 3600Mhz and CL 16 .... Hurray!

 

[.Apex.]

19 minutes ago, JackMaro said:

Thanks so much! I couldn't find the XMP profile, because i didn't know about D.O.C.P. 

After googled a little bit, i found that D.O.C.P option was available under AI Overclock Tuner. After i set it to D.O.C.P, it notified me about FCLK and 1:1 and changed it all, so it was propper 1:1. Thanks!

 

DOCP is also found on the main BIOS screen, it's AMD's implementation of XMP but some AMD boards use XMP naming scheme so that's why I mention both of them, it gets confusing but they're basically the same.

14 minutes ago, JackMaro said:

I guess, the NB Frenquency has to be doubled right? If so, then it should run 3600Mhz and CL 16 .... Hurray!

Yes it's all running correctly you're welcome

[mr mans]

Hey where do I check if I have my infinity fabric at 1:1? I've got the XMP profile running for my 3600mhz/CL16 memory on my Asrock X570 board. Is it just automagic?

[djgarygillespie]

I'm wanting to buy an 3900x (maybe the 3950x), I've never overclocked my memory in the past and I'm not sure which kit to buy for this Infinity Fabric.

I'm going to get one of these kits:

 

G.SKILL Trident Z Neo DDR4 3800 (PC4 30400)
Timing 14-16-16-36, CAS Latency 14, Voltage 1.5V

or

G.SKILL Trident Z Neo DDR4 3600 (PC4 28800)
Timing 14-15-15-35, CAS Latency 14, Voltage 1.45V

 

Should I go with the 36000 to keep Infinity Fabric 1:1, or go with the 3800 kit and the ratio would go 2:1?  From what I can tell you don't want a 2:1 ratio.
If I go with the 3800 kit is there a way to make it to 3600 and change the Timings, is that what DRAM Tool would show me?

 

I'm a noob and thanks for the help Gary.

[jellowiggler]

Stick with the 1:1 ratio and 3600.  Go with low CAS latency like 16 if you can.

 

Over 3600 is diminishing returns on Zen 3.

[infigo]

On 1/18/2020 at 4:27 PM, JackMaro said:

I guess, the NB Frenquency has to be doubled right? If so, then it should run 3600Mhz and CL 16 .... Hurray!

 

One thing I see that is the same "issue" that I have. Very common with that kit. The bank cycle time (tRC) should really be 58...not 85.

Apparently that kit is read the tRC wrong on many motherboards when setting xmp/docp.

Not a huge thing but you can go into bios and change it manually. 

[Shadowarez]

i just built a new amd rig asus Dark Hero x570 amd ryzen 9 5900x and this gskill kit 32gb 3600 cl 16 

what has me wondering if im running fab clock at 1/1 is fsb:dram shows 3:54 

 

 

[Shadowarez]