PC Processors

[MADZyren]

I am thinking about new 7700X and X670, but have hard time choosing memory.

I know AMD recommends 6000 as sweet spot or something like that, with AUTO:1:1 settings

Some reviewers use faster than 6000MT/s kits

Anandtech said this "...if memory speeds exceed 3000MHz (DDR5-6000), then the memory controller will fall to 1:2 with the memory frequency, which will incur a performance hit."

But is that a hard, built in limit, or is it like with 3000-series, where Infinity Fabrik can go to 1800MHz for DDR4-3600 kits, perhaps 1866 to run DDR4-3733, but more only with luck?

So is there a chance, Ryzen 7700X can run 1:1:1 with sticks running faster than 6000?

[markus7912]

The Infinity fabric have a maximum stabil frequency 2100 Mhz and it is runing in asynchronous mode. The AMD love recommend the most expensive Rams , but if you buy DDR5 5200 CL36 the difference is not significant. If you will buy the most expensive DDR5 6000 CL 30 ... its your choice. The difference is minimal. AMD EXPO and Intel XMP compatible rams works fine. You dont lose much if you dont spend 100 -120 USD extra.

Here is a test you need to decide you buy a cheap DDR5 or the most expensive:  https://www.youtube.com/watch?v=OR54YZMZ0mc

[MADZyren]

Not looking for best bang for buck, but want to try pushing things to their limit. Not sure what I'll buy this time though, but if you get a fast DDR5 kit from the beginnig, you can use it on future builds. (if you got DDR4-3200 - 3600, you could use it till the end of DDR4, but if you got 2400-2800, you likely wanted to get something faster on the way).

DDR5-6000 runs at 3000MHz, but IF is only 2000MHz?

So

edit: DDR5-6300 : 3150MHz : 2100 MHz would offer lower latency and more performance, but according to Anandtech, then the memory controller would drop to 1575MHz? :edit

Unfortunately 64 Gb kits with reasonable clockspeeds an latencys are not available, atleast yet.

[markus7912]

According to Gamers Nexus ( Tech Jesus ) the ratio for the infinity fabric is AUTO : 1 : 1. If you use DDR5 6000 The Motherboard knows the best Infinity fabric clock is 2000 Mhz for you. If you use slower DDR5 then it will be automaticly adjusted for the best frequency.

This video help to understand: https://www.youtube.com/watch?v=ZzhxW7uu9EI

0:4.47 have an oficial AMD example.

The problem is in the nex 6 months we see a lot faster DDR-7200 maybe even DDR5-8000 too. You lose Money for no reason. If you will more performance buy 1 tier higher CPU with the cheaper Ram.  Im Ok whatever you decide its your Money.

There is something from Buildzoid: "If you have 4 DDR5 slot, but you occupy only 2 the other 2 free slot can make interference, and for this high frequency moduls it can be a Problem."

I also ordered the Gskill F5-6000J3038F16GX2-TZ5N but im not sure do i will pay 2X price for the X670E - I or for the B650E - I. The Raptor lake is also a considerable option With a much cheaper Z690 or Z790 DDR5 Mobo. For me 2 DDR5 slot is enough.

Im not buying anithing until i did not see the full picture and a Value build.

[battyus]

Based upon all the articles so far out there, I've opted to get the F5-6000J3038F16GX2-TZ5NR kit from G.Skill, which offers 6000MHz in the Expo profile. It is "only" 32GB, but I've figured it will be good for a start until the platform gets more mature. So far it runs on 6000MHz, so I am satisfied with it.

I'm waiting for the 64GB kits to be available, and maybe the 6000 "sweetspot limitation" will be broken too in the future.

[MADZyren]

With more information now, I would like to narrow the question if anyone knows, is the memory controller 3000MHz limit a hard limit, making DDR5-6000 the fastest clockspeed option without memory controller falling to 1:2 speed?

[goodplay]

If you want more solid info., check out some OCers forums. 

[markus7912 · Accepted solution]

Maybe you find the right answers here:

https://videocardz.com/newz/amd-confirms-ryzen-7000-memory-sweet-spot-is-ddr5-6000

[Anonymous]

all true super computers are starting from CAS 0 and below ..

INFINITY FABRIC means that RAM and CPU arent the same clock speed fixed so lets you gain more flexibility and asynchronous compute.. things like freesync which need a true super computer to begin to function as intended and was invented as optical technology for the 60s from AMD like ethernets and fibrechannel and optical internet .. which requires sub 0 nanosecond ping times.. which intel and nvidia still use CAS58 DDR5 and fake all their specs and timings and are the nastiest turds in the universe. For infinity fabric to work best have it perfect 1/4 or 1/2 or 1:1 or whatever ratios of mhz and fabric weave. its sorta like half duplex full duplex networking with multilayer adsl filtering like subscattering.. remember when AMD technology makes a dialup model into ADSL/VDSl/CABLE/optic fibre in the 60's or whatever? and you can make it fast as you want by adjusting the asynchronous compute and compressonator and cache (infinity cache infinitely) or compressonator and stuff? they call it DOCSIS. thats the part of the better than true super computer RYZEN stuff they let you use nowadays and pretend AMD didnt always have it.. but no optical and satellite communications and stuff always existed.. they pretended that it took ages for light to travel around the world and have delays chatting on phone calls and stuff noobs.

DDR5 is like CAS50 something.

disable FAKE XMP that has more latency each year.. DDR3 was CAS1-4 you could set it to CAS1.

set what the XMP wanted for in voltages manually and lower the mhz low as it will go.. disable geardown mode and use command rate 1T.

use lowest latency you can stably boot with and runs faster with a bench mark or stress test no crash with manually adjusted secondary memory timings which maybe needs you a bunch of trial and error reboots and clear cmos jumper pins on the board to figure out. use samsung factory timings as reference and try programs like typhoon burner that let you custom edit XMP profiles or flash all the cheap ram to become the expensive ram or the other way around and force them to not work for AMD computers or partially uncripple them...