# Problems with getting stable 3800mhz RAM with Ryzen 3900X and timings to check



## Gegu (Sep 25, 2020)

Hello.

The platform I have is:

- Ryzen 3900X (chip from this year, bought few months ago) undervolted by - 0.1V
- ASUS Crosshair VIII Hero WiFi motherboard with the latest bios
- RAM DDR4 32GB (4x8GB) G.Skill Tridentz Neo 3800mhz CL14 1.5V

I have problems with maintaining stability on 3800mhz memory clock. Well, sometimes the PC boots properly with the XMP profile turned on (but always the second time it turns on, rarely the second time), and sometimes it tries to turn on several times, but eventually it doesn't turn on with the XMP profile and then the RAM has 2133mhz clocking.

Memory voltage according to XMP profile is 1.5V. However, the motherboard registers 1.496V at this value, so I have to set the memory to 1.51V for the motherboard to register the full 1.5V

For the XMP profile to work sometimes I have to set the FCLK value in bios manually to 1900mhz - setting the auto option causes pc to have even more problems with boot.

If I can already boot a PC with XMP profile enabled, then Infinity Fabric works well in 1:1 mode.

After reducing the memory clock to 3733mhz and setting the FCLK manually to 1866mhz everything works very well - the computer boots immediately, there are no problems and the memory always works.

Do you have any idea what I could do with these memories to make them work well with XMP profile turned on? Maybe some options in BIOS? Or am I just not lucky and my chip is not stable at IF 1900mhz?

By the way, I'm asking you to judge the timings - I've been reducing it based on DRAM Calculator and some knowledge from the Internet, but I don't know about it and maybe there are some values to correct.


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## Tatty_One (Sep 25, 2020)

What are your VCCSA and VCCIO set at?  Some boards just don't play as nice with all 4 RAM slots populated, if those voltages are set at auto in the Bios sometimes manually tweaking them upwards a little can help, if they are auto the Bios should tell you what voltage it is actually giving them...……. however for 24/7 operation you should try to stay under 1.25v …. well I do!


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## Gegu (Sep 25, 2020)

Tatty_One said:


> What are your VCCSA and VCCIO set at?  Some boards just don't play as nice with all 4 RAM slots populated, if those voltages are set at auto in the Bios sometimes manually tweaking them upwards a little can help, if they are auto the Bios should tell you what voltage it is actually giving them...……. however for 24/7 operation you should try to stay under 1.25v …. well I do!


thanks for help - i will check it and try change if they are on auto


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## sneekypeet (Sep 25, 2020)

If you feel that it is the Infinity Fabric causing the issue, manually set it to 1600 and see if the RAM runs without issue.

Also, if it wont run with XMP, it is highly unlikely that lowering the timings is going to magically fix things (IE the screenshot of 14-13-13 timings).

I believe what you are looking for from @Tatty_One is called SOC.


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## Gegu (Sep 25, 2020)

sneekypeet said:


> If you feel that it is the Infinity Fabric causing the issue, manually set it to 1600 and see if the RAM runs without issue.
> 
> Also, if it wont run with XMP, it is highly unlikely that lowering the timings is going to magically fix things (IE the screenshot of 14-13-13 timings).
> 
> I believe what you are looking for from @Tatty_One is called SOC.



I set it to 1833 and it is running without issue, only 1900 1:1 IF is causing boot problems - sometimes is booting with XMP and working, sometimes not. I tightened timings not for fixing it, only for fun


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## sneekypeet (Sep 25, 2020)

Gegu said:


> I set it to 1833 and it is running without issue, only 1900 1:1 IF is causing boot problems - sometimes is booting with XMP and working, sometimes not. I tightened timings not for fixing it, only for fun



Seems like you have your answer already then. With my 3900X I do not have to change anything to get 1900 IF stable. And I am on the same motherboard. I would hazard to guess you may be banging your head against a hard wall trying to get 1:1 at that speed.

You do realize that you can also set 3200MHz ram speed, and then try to test the IF on its own to see where it tops out? They do not have to be linked to test to see if they run.


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## Gegu (Sep 25, 2020)

Tatty_One said:


> What are your VCCSA and VCCIO set at?  Some boards just don't play as nice with all 4 RAM slots populated, if those voltages are set at auto in the Bios sometimes manually tweaking them upwards a little can help, if they are auto the Bios should tell you what voltage it is actually giving them...……. however for 24/7 operation you should try to stay under 1.25v …. well I do!


Do you mean both VDDP voltage options? I cant find in bios anything named VCCSA and VCCIO


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## sneekypeet (Sep 25, 2020)

Gegu said:


> Do you mean both VDDP voltage options? I cant find in bios anything named VCCSA and VCCIO



See the end of post #4


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## Gegu (Sep 25, 2020)

sneekypeet said:


> See the end of post #4


 Yea, right  But isnt SOC related somehow to CPU?


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## sneekypeet (Sep 25, 2020)

Gegu said:


> Yea, right  But isnt SOC related somehow to CPU?



yep...

*"SOC voltage* is what drives all of the *System on Chip* devices, such as the I/O controller, Memory controller, etc. When you are overclocking you should set *SOC* to 1.1v, and you can increase that *voltage* up to 1.2v or 1.25v depending on who you listen too (AMD has not released any guidance around max *SOC voltage*)."

^^ borrowed from reddit.


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## Gegu (Sep 25, 2020)

sneekypeet said:


> yep...
> 
> *"SOC voltage* is what drives all of the *System on Chip* devices, such as the I/O controller, Memory controller, etc. When you are overclocking you should set *SOC* to 1.1v, and you can increase that *voltage* up to 1.2v or 1.25v depending on who you listen too (AMD has not released any guidance around max *SOC voltage*)."
> 
> ^^ borrowed from reddit.


Thank you for answer, im bad in OC so im asking


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## Taraquin (Sep 25, 2020)

If 3733 work well I would stick with that, there is very little gain from 3733 to 3800. 1.5V is a bit on the high end on the ram. As for timings, why not use the fast preset i dram calc and tune further? Some of your timings now are far from optimal speedwise. tRRDS and tRRDL should be 4 if possible. tFAW is derived from tRRDS and is always tRRDS x 4, minimum effective value is 16. tWR should be 10-12.


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## Tatty_One (Sep 25, 2020)

Gegu said:


> Do you mean both VDDP voltage options? I cant find in bios anything named VCCSA and VCCIO


Yeah apologies, I was talking in Intel speak


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## Gegu (Sep 25, 2020)

Tatty_One said:


> Yeah apologies, I was talking in Intel speak


Thanks - I tried changing SOC voltage, but it didnt help. What voltage for both VDDP options would you recommend for better RAM stability?



Taraquin said:


> If 3733 work well I would stick with that, there is very little gain from 3733 to 3800. 1.5V is a bit on the high end on the ram. As for timings, why not use the fast preset i dram calc and tune further? Some of your timings now are far from optimal speedwise. tRRDS and tRRDL should be 4 if possible. tFAW is derived from tRRDS and is always tRRDS x 4, minimum effective value is 16. tWR should be 10-12.


Thanks, ill aplly that


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## Tatty_One (Sep 25, 2020)

Gegu said:


> Thanks - I tried changing SOC voltage, but it didnt help. What voltage for both VDDP options would you recommend for better RAM stability?
> 
> 
> Thanks, ill aplly that


What is auto setting them to?


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## sneekypeet (Sep 25, 2020)

Tatty_One said:


> What is auto setting them to?



SOC should be like 1.08v. Never needed more than 1.18v on my C8H, but my IF can run 1900 without the need to bump it. This is why I feel the OP hit a hard wall, and that lowering ram for 1:1 without dropping the IOH to half its speed in the attempt might be the better solution as taraquin put in his post.


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## Gegu (Sep 25, 2020)

Tatty_One said:


> Yeah apologies, I was talking in Intel speak


Unfortunatelly uppering this values didnt make my RAM run on 3800mhz - ive tried many settings. I think that ill stay with 3733, its not bad to be honest


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## Sround14 (Sep 30, 2020)

Gegu said:


> Hello.
> 
> The platform I have is:
> 
> ...



Hi, I feel your pain . Not sure if you can help me as I have the same/similiar issue. I have the crosshair hero viii but standard version none wifi and everything was running fine until I did the latest bios update to 2206. I had some crucial ballistix 3600mhz and docp was enabled and working great. After the bios update I could not get this to run at all and just thought it was something to do with the ram so decided to upgrade to the same g.skill 3800mhz cl14 that you have. If I enable docp it just throws a fit and get a black screen. It did launch once, the firsttime but after that it stopped so had to reset bios. I can only seem to get this machine to boot at the bog standard 2133mhz. I dont suppose you can send the screenshots of how you have it setup to run at 3733mhz at 1:1. I have the same 3900x cpu as well and rtx 2080ti gaming z card. I am a complete noob at this but want a real competitive machine. But I am just completely stuck on getting ram to work at a decent speed on this board with the latest bios update. Wish Id just left it at the original bios version which it was out of the box.



Sround14 said:


> Hi, I feel your pain . Not sure if you can help me as I have the same/similiar issue. I have the crosshair hero viii but standard version none wifi and everything was running fine until I did the latest bios update to 2206. I had some crucial ballistix 3600mhz and docp was enabled and working great. After the bios update I could not get this to run at all and just thought it was something to do with the ram so decided to upgrade to the same g.skill 3800mhz cl14 that you have. If I enable docp it just throws a fit and get a black screen. It did launch once, the firsttime but after that it stopped so had to reset bios. I can only seem to get this machine to boot at the bog standard 2133mhz. I dont suppose you can send the screenshots of how you have it setup to run at 3733mhz at 1:1. I have the same 3900x cpu as well and rtx 2080ti gaming z card. I am a complete noob at this but want a real competitive machine. But I am just completely stuck on getting ram to work at a decent speed on this board with the latest bios update. Wish Id just left it at the original bios version which it was out of the box.


And I just have 16gb to sticks not the 32gb like you have


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## Gegu (Sep 30, 2020)

Sround14 said:


> Hi, I feel your pain . Not sure if you can help me as I have the same/similiar issue. I have the crosshair hero viii but standard version none wifi and everything was running fine until I did the latest bios update to 2206. I had some crucial ballistix 3600mhz and docp was enabled and working great. After the bios update I could not get this to run at all and just thought it was something to do with the ram so decided to upgrade to the same g.skill 3800mhz cl14 that you have. If I enable docp it just throws a fit and get a black screen. It did launch once, the firsttime but after that it stopped so had to reset bios. I can only seem to get this machine to boot at the bog standard 2133mhz. I dont suppose you can send the screenshots of how you have it setup to run at 3733mhz at 1:1. I have the same 3900x cpu as well and rtx 2080ti gaming z card. I am a complete noob at this but want a real competitive machine. But I am just completely stuck on getting ram to work at a decent speed on this board with the latest bios update. Wish Id just left it at the original bios version which it was out of the box.
> 
> 
> And I just have 16gb to sticks not the 32gb like you have




Hi, I'll try to help you 

First of all - Try to set the XMP (DOCP) profile for RAM in the bios, but set the FCLK (an option in the extreme tweaker in the bios tab) manually to 1900mhz and see if it boots without problems. If so, you can start checking if the IF works in 1:1 mode (e.g. in CPU-Z checking North Bridge frequency (should be 1900mhz), or in Ryzen Master checking if Coupled Mode is on).  

If the XMP profile is enabled and the FCLK 1900mhz pc does not boot, you have 2 options:

- the first one: you downgrade the bios to the last stable version, i.e. (probably) 2103, and then you check if the pc will boot on according to the instructions given above

- Second: Instead of enabling the DOCP (XMP) profile, you set it to Manually. Then you select the 3733 mhz frequency and set the FCLK manually to 1866 mhz. When setting manually, you must also change the voltages in the DRAM voltage section to 1.5V (or 1.51V for full 1.5V). You check if the computer boots - if it does, then you check if the IF works in 1:1. If it works in 1:1, you go back to bios and change the timings. Because the timings from the manual option are very weak. You can try mine from the screenshot, they are very optimized timings. The only thing you can change is to set tRFC for 260-70 instead of 250 - 250 is a stability limit where it doesn't show errors yet.

Even if it only works in 3733mhz you have nothing to worry about, the difference between 3733 and 3800 with these delays is maybe 1 frame per second in games. Nothing that can be noticed.


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## Sround14 (Oct 1, 2020)

Gegu said:


> Hi, I'll try to help you
> 
> First of all - Try to set the XMP (DOCP) profile for RAM in the bios, but set the FCLK (an option in the extreme tweaker in the bios tab) manually to 1900mhz and see if it boots without problems. If so, you can start checking if the IF works in 1:1 mode (e.g. in CPU-Z checking North Bridge frequency (should be 1900mhz), or in Ryzen Master checking if Coupled Mode is on).
> 
> ...


Thanks for getting back so quickly. I had a right game with this last night. The best I can achieve is turning on xmp/docp and setting the values to dram =3533 and FCLK to 1766. Not ideal but atleast its something. As soon as I set it to 3600mhz it fails to boot. I tried rolling back Bios and it would only let me go back to the previous update, If I tried the one before that or any further back it just said it wasn't  a proper bios but its the ones from the asus download site. I have also logged a call with asus. Not sure if anyone has had success with them or I'm wasting my time. Below is some images of how it is currently setup.


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## Calmmo (Oct 1, 2020)

From a quick glange at your timings (outside of likely needing more voltage somewhere) your TRFC seems suspect. 250 is really low, try something in the 300 range.


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## Pieruzan (Oct 1, 2020)

I have a Ryzen 3700x with aorus elite x570, I have been chasing 1900 IF 1: 1 stable memory clock for months but without success, it was stable at 3733 unstable at 3800, I tried them all, until, by chance, I disabled the spread spectrum, from that moment the ram at 3800 is stable.
I don't know if it can help you.


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## Gegu (Oct 1, 2020)

Pieruzan said:


> I have a Ryzen 3700x with aorus elite x570, I have been chasing 1900 IF 1: 1 stable memory clock for months but without success, it was stable at 3733 unstable at 3800, I tried them all, until, by chance, I disabled the spread spectrum, from that moment the ram at 3800 is stable.
> I don't know if it can help you.


What is spread spectrum?


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## Pieruzan (Oct 1, 2020)

Gegu said:


> What is spread spectrum?


an option, active by default, created to limit magnetic interference but which can also make RAM overclock unstable


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## Gegu (Oct 1, 2020)

Pieruzan said:


> an option, active by default, created to limit magnetic interference but which can also make RAM overclock unstable


Which tab in bios contain it?

I think i solved my problem  I had to change ProcODT ohms to 36.9 and raise DRAM voltage to 1.53 (default for this b-die kit is 1.5) and now system is booting all the time with IF 1:1 with tightened timings


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## Pieruzan (Oct 1, 2020)

Gegu said:


> Which tab in bios contain it?
> 
> I think i solved my problem  I had to change ProcODT ohms to 36.9 and raise DRAM voltage to 1.53 (default for this b-die kit is 1.5) and now system is booting all the time with IF 1:1 with tightened timings


happy to ear that, but "system is booting all the times" is not enough, there is need some serious mem test


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## Gegu (Oct 1, 2020)

Pieruzan said:


> happy to ear that, but "system is booting all the times" is not enough, there is need some serious mem test


I know, but this is still some progress for me  Of course ill do some memtest, which will be good for testing it?

And thats my results after tightening all timings to some good values:


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## Adhyaksa17 (Oct 8, 2020)

Gegu said:


> I know, but this is still some progress for me  Of course ill do some memtest, which will be good for testing it?
> 
> And thats my results after tightening all timings to some good values:
> 
> View attachment 170461View attachment 170462


I think you can change the trrds to 4 and trrdl to 6, tfaw to 16 or 24, combination of twtrs and twtrl 2 8, or 3 7, or 4 8.
Your latency is slightly higher than the other 3800 cl14, you need to change your sub timing to get your best. Fyi my 3300x on B450M mobo @4.3ghz B-die @3800 cl14-15-14-14-21-40 1.475v have latency 59.8 ns, and this set up is fully stable 24/7. I know my set up only have 1 CCD and yours 2 CCD that's means you may get more copy performance and slightly higher latency, but i think you can tweak again your memory sub timing to get slightly better latency


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## Gegu (Oct 8, 2020)

Adhyaksa17 said:


> I think you can change the trrds to 4 and trrdl to 6, tfaw to 16 or 24, combination of twtrs and twtrl 2 8, or 3 7, or 4 8.
> Your latency is slightly higher than the other 3800 cl14, you need to change your sub timing to get your best. Fyi my 3300x on B450M mobo @4.3ghz B-die @3800 cl14-15-14-14-21-40 1.475v have latency 59.8 ns, and this set up is fully stable 24/7. I know my set up only have 1 CCD and yours 2 CCD that's means you may get more copy performance and slightly higher latency, but i think you can tweak again your memory sub timing to get slightly better latency


Thanks for advice, i will test this settings. But remember, that I have 4 sticks each 8GB, so they are harder to get as stable and fast as set of two ddr4 3800cl14 sticks. I dont think that I can go below 63 ns with this kit


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## Sround14 (Oct 13, 2020)

@Gegu Don't suppose you could attach screenshots of how you have this setup in your BIOS? Do you leave docp disabled and just manually enter all the settings? At present I have docp enabled but highest I can set the dram at is 3400 1700flck to get the PC running stable. I am a complete noob to this so if I could copy every setting and go from there?


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## Gegu (Oct 13, 2020)

Sround14 said:


> @Gegu Don't suppose you could attach screenshots of how you have this setup in your BIOS? Do you leave docp disabled and just manually enter all the settings? At present I have docp enabled but highest I can set the dram at is 3400 1700flck to get the PC running stable. I am a complete noob to this so if I could copy every setting and go from there?


Hi, I think I can help you. 

At first - which cpu and ram kit do you have? Can you give me full name?

Second - tell me, which manufacturer motherboard do you have? Mine is from ASUS, every motherboard manufacturer have different bios.

My kit is 32GB 3800mhz CL14. I have DOCP enabled, FCLK set manually to 1900mhz. My XMP voltage for DRAM is 1.5V, but to get stable boot i need 1.525V I also changed ProcODT value to 36.9 ohm.

If you have any other question, feel free to ask


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## Zach_01 (Oct 14, 2020)

Gegu said:


> My kit is 32GB 3800mhz CL14. I have DOCP enabled, FCLK set manually to 1900mhz. My XMP voltage for DRAM is 1.5V, but to get stable boot i need 1.525V I also changed ProcODT value to 36.9 ohm.
> 
> If you have any other question, feel free to ask


It is wiser, usually better, to disable XMP/DOCP in BIOS when manual settings are made at some timings. 
All RAM sticks have way more timing settings than the ones visible. XMP/DOCP set all these. When we adjust some timings manually it may be better to let all other (the ones on Auto or not visible) to be configured by the board according to your settings. This could have major impact on latency because your settings and what XMP/DOCP “decides” for secondary and not visible ones don’t comply well.

One try will show what’s better. Just disable DOCP, leave everything else as it is and run AIDA benchmark again.


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## Gegu (Oct 14, 2020)

Zach_01 said:


> It is wiser, usually better, to disable XMP/DOCP in BIOS when manual settings are made at some timings.
> All RAM sticks have way more timing settings than the ones visible. XMP/DOCP set all these. When we adjust some timings manually it may be better to let all other (the ones on Auto or not visible) to be configured by the board according to your settings. This could have major impact on latency because your settings and what XMP/DOCP “decides” for secondary and not visible ones don’t comply well.
> 
> One try will show what’s better. Just disable DOCP, leave everything else as it is and run AIDA benchmark again.


Thanks, i didnt know. for sure ill try!


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## Zach_01 (Oct 14, 2020)

Gegu said:


> Thanks, i didnt know. for sure ill try!


As long as you manually set DRAM multi to X38 or 3800MHz and the primary timings to your liking.


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## xman2007 (Oct 14, 2020)

Nice read, write and copy numbers there, defo beat mine at 3600 c16... not by much though


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## Gegu (Oct 14, 2020)

Zach_01 said:


> As long as you manually set DRAM multi to X38 or 3800MHz and the primary timings to your liking.



Well i tried, but nothing changed - im back to DOCP


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## Sround14 (Oct 16, 2020)

Gegu said:


> Which tab in bios contain it?
> 
> I think i solved my problem  I had to change ProcODT ohms to 36.9 and raise DRAM voltage to 1.53 (default for this b-die kit is 1.5) and now system is booting all the time with IF 1:1 with tightened timings


Are you running at 3800mhz 1900fclk stable now? Are all the timings still the same as your original post along with these 2 changes on ProcODT ohms and the dram voltage. Have to say this is no fun at all


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## Gegu (Oct 16, 2020)

Sround14 said:


> Are you running at 3800mhz 1900fclk stable now? Are all the timings still the same as your original post along with these 2 changes on ProcODT ohms and the dram voltage. Have to say this is no fun at all


Yes, I am now running it stable. ProcODT 36.9 ohm. DRAM Voltage 1.525V. Timings you can check on actual screenshot. The only thing ill probably change will be tRFC, but I have to test stability with  different values (250-280)


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## Sround14 (Oct 22, 2020)

Gegu said:


> Hi, I'll try to help you
> 
> First of all - Try to set the XMP (DOCP) profile for RAM in the bios, but set the FCLK (an option in the extreme tweaker in the bios tab) manually to 1900mhz and see if it boots without problems. If so, you can start checking if the IF works in 1:1 mode (e.g. in CPU-Z checking North Bridge frequency (should be 1900mhz), or in Ryzen Master checking if Coupled Mode is on).
> 
> ...


Hi Gegu have you seen the BIOS update released this week with dram compatibilty? Just enabled docp and it works like a dream. I did have to set flck to 1900 but my PC boots everytime now. Been testing the last hour


Gegu said:


> Hello.
> 
> The platform I have is:
> 
> ...


Hi Gegu, have you seen the latest bios release this week from asus for the crosshair viii. It has improved dram compatibility and has worked for me. I have been testing for about an hour and seems fine


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## Gegu (Oct 22, 2020)

Sround14 said:


> Hi Gegu have you seen the BIOS update released this week with dram compatibilty? Just enabled docp and it works like a dream. I did have to set flck to 1900 but my PC boots everytime now. Been testing the last hour
> 
> Hi Gegu, have you seen the latest bios release this week from asus for the crosshair viii. It has improved dram compatibility and has worked for me. I have been testing for about an hour and seems fine



Hi,
I didnt know abut new bios - i will try it for sure. Maybe my tweaks with voltage wont be neccesary now. Thank you!

I am also happy that you can boot without problems. Now you can tighten your ram timings, you can use my settings - they are working well, look at attached file.



Sround14 said:


> Hi Gegu have you seen the BIOS update released this week with dram compatibilty? Just enabled docp and it works like a dream. I did have to set flck to 1900 but my PC boots everytime now. Been testing the last hour
> 
> Hi Gegu, have you seen the latest bios release this week from asus for the crosshair viii. It has improved dram compatibility and has worked for me. I have been testing for about an hour and seems fine



Hi, i checked this newest bios -my dram voltage in bios still need to be uppered to 1.525 - 1.53, nothing changed.But its working, so it isnt bad


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## RicardoMadGello (Nov 17, 2020)

Gegu said:


> I set it to 1833 and it is running without issue, only 1900 1:1 IF is causing boot problems - sometimes is booting with XMP and working, sometimes not. I tightened timings not for fixing it, only for fun



1900MHz on Infinity Fabric is Not Always Going To Happen, especially on pre-Zen 3, where it is even still a Maybe, from the grapevine.

Be happy with the lower 3733MHz setting that is Stable.

As it say on the G.Skill site for this and other RAM in there, "Additional NotesR RatedXMP frequency & stability depends on MB & CPU capability."

Is your motherboard on this page's QVL for this part #?









						F4-3800C14D-16GTZN - Specification - G.SKILL International Enterprise Co., Ltd.
					

Trident Z Neo DDR4-3800 CL14-16-16-36 1.50V 16GB (2x8GB)




					www.gskill.com
				




There's tons of articles in why 1900MHz probably won't happen on Zen 2, 2+, and Zen 3.


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## Gegu (Nov 17, 2020)

RicardoMadGello said:


> 1900MHz on Infinity Fabric is Not Always Going To Happen, especially on pre-Zen 3, where it is even still a Maybe, from the grapevine.
> 
> Be happy with the lower 3733MHz setting that is Stable.
> 
> ...


Yes, it is


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