xmp 4000mhz does this make any sense to you guys?

[chrisryan01]

got a new ram kit today 4000mhz cl18 for Ryzen. set my xmp looked at my settings and my speed is right but every time i try and match my IF my Nb frequency gets set to this... in Ryzen master it shows mem clock at the right speed but the IF at 1800. but cpu z shows 998 mhz lol I'm confused af

help would be dope... i try to mainly set my IF to 2000 to match and it doesn't boot. 

 

my specs

b550 aorus master 

ryzen 5 3600

16 gb ddr4 4000mhz c18

3080 xc3

 

 

[Guest]

First list system specs.

Then ask questions. 

[Grabhanem]

Ryzen can very rarely do more than 1850-1900 on Infinity Fabric. My guess is it's just not stable at that speed.

[chrisryan01]

1 minute ago, ShrimpBrime said:

First list system specs.

Then ask questions. 

im sorry kinda new to this page, 

 

b550 aorus master 

ryzen 5 3600

16 gb ddr4 4000mhz c18

3080 xc3

 

[svmlegacy]

Infinity fabric is getting divided by 2 either because of instability (Most CPU's can't hit 2000 IFck), or automatically ( unless set for 1:1 ratio, it gets divided by 2 for speeds > 3600 MT/s)

[chrisryan01]

2 minutes ago, Grabhanem said:

Ryzen can very rarely do more than 1850-1900 on Infinity Fabric. My guess is it's just not stable at that speed.

yeah it runs stable at 1900, and when i set it to that it shows up correctly in cpu-z

just never seen  Nb frequency get set to 933. just didnt know if that was normal for a 4000mhz kit or what. 

ill just run it at 1900/1900 then. thanks for the info 

[chrisryan01]

4 minutes ago, svmlegacy said:

Infinity fabric is getting divided by 2 either because of instability (Most CPU's can't hit 2000 IFck), or automatically ( unless set for 1:1 ratio, it gets divided by 2 for speeds > 3600 MT/s)

i got you man thanks for the info. never tried to run a 4000mhz kit before. xmp loads fine but IF is tricky. thanks for the info tho. just gonna ruin it at 1900/1900

mainly got the kit so i have a high frequency kit for zen 3 when it comes out to play around with. i got a 3200 c16 kit as well thats 32gb

[boggy77]

If if runs at 1900, try to run ram at 3800 and tighten rimings

[chrisryan01]

2 minutes ago, boggy77 said:

If if runs at 1900, try to run ram at 3800 and tighten rimings

okay thank you, im good with everything els pc related besides mem oc lol. so im learning now. i got it at 1900 with 18-22-22-42 at 1.35 

gonna do some reading up and learning and tighten my timings later. thanks for all the info tho guys!!

[Cyracus]

Ive seen tests showing overcoming the desync penalty at 3933/4000mhz+. Up to you to decide if testing is worth it. This guide has been useful to me https://github.com/integralfx/MemTestHelper/blob/master/DDR4 OC Guide.md#recommended