Need help with 3900x getting to 1867 IF clock

[leepox]

I am currently running stable at 1833 IF with CL16 timings at 1.38v (Micron E Die). VDDP 0.9, VDDG 0.95, and SOC at 1.05

I can boot at 1867 IF (SOC increased to 1.12v) with timings based on DRAM calc and I end up with random restart like when the PC is on idle and the monitor screen turns off (workaround was to keep monitor on at all times) and when playing games after a period of time. I even tried looser timings and set the sub timings to auto which solved the monitor off causing restart issue.

The biggest thing I've noticed was the drop in benchmark performance in cinebench R20, CPU-Z, 3DMark, and most especially Membench. Like, at my 1833 IF setting I'm getting 120-130 seconds. At 1867 I'm getting 200 seconds.

Should I just settle for 1833, or is there a chance of getting this CPU to run stable at 1867. Because I can even boot into windows at 1900 IF (but a very choppy, unstable experience)

 

[EarthDog]

To me, the effort to get there isn't worth the returns at all. You've already pushed the platform and getting 99%+ of its performance.

 

[leepox]

I like the alternate viewpoint. I guess in that sense I'll just focus on getting a B die and get even more tighter timings than what this micron e is capable of?

 

[EarthDog]

Even that (dies in memory kits)... isn't worth the effort unless you are benchmarking competitively. If you want to, get on it... just know where you're at, the ends doesn't justify the means.

Where are you currently at timings wise? What kit? Take a couple mins and fill in your system specs so we have an idea what you are working with.

 

[leepox]

Just trying to get sub 65ns latency I guess and get close to that 100s mark in membench just for fun.

MSI B550 gaming itx, ballistix 3600 cl16, 3900x, 5700xt, 650w psu.

I've pushed cl15 but membench starts logging errors. I have high hopes getting cl14 with a B die.

 

[tabascosauz]

Just trying to get sub 65ns latency I guess and get close to that 100s mark in membench just for fun.

MSI B550 gaming itx, ballistix 3600 cl16, 3900x, 5700xt, 650w psu.

I've pushed cl15 but membench starts logging errors. I have high hopes getting cl14 with a B die.

Rev.E is an excellent frequency overclocker. Rev.E is not known for its tight secondary timings. That's just how it is; CJR and Rev.E will get you to the frequency you want and pretty much all the practical performance, but if the e-peen satisfaction of looking at the timings on the screen is what you want then you still can't beat B-die.

I'm at between 115s and 120s @ 3600, 113-115s @ 3733, and can't get below 113s so far @ 3800, depending on whether I have GDM on or off. I don't think the second-tier ICs like CJR and Rev.E have any more oomph in them short of 1.5V DRAM voltage, but you will need to put in the manual work on your secondary timings if you want to at least get to that point.

All voltages are looking low. Get your SOC up to 1.1V and stay there. Both VDDGs set about 0.05V lower than SOC, and get VDDP up to at least 0.950V. Start from there. Expect to require anywhere between 1.35-1.45V on the memory for completely stable 3733.

3733 should be doable; 3800 is completely luck of the draw, you can only change everything you can and hope for the best. I wouldn't place my hopes on a stable daily 3800 unless there is some other indication that your CPU is of excellent quality (ie. high all-core OC at 1.2-1.3V)

 

[leepox]

I think the observable drop in performance (I mean not that much) at the higher IF is sure signs of instability. I bumped up the SoC voltage to 1.12 and the VDDP/G and the performance was 100 points down on Cinebench and dropped even further when I turned on the PBO. I guess the second sub-par die of the 3900x is holding me down? (But also read that IF is completely independent of die bins)

at 3666 CL16 I score around 119s in membench, and when I tried CL15, it dropped to 113s which is much better than my score for 3733 CL16. So I'm hoping that the lower frequency will allow me to hit CL14 with ease (with a B die) and leave it at that (hopefully hitting 110s and sub 65ns). I'll probably wait for the next BIOS to see if 3733 runs more stable.

It's quite frustrating how it's at the knife edge of stability at 3733 as I can successfully run benchmarks, game, etc. but with signs that it's not quite happy at that IF speed (random but not frequent restarts, and the slight performance drop). Oh well, I'll just have to wait for the 4000 series and justify buying a 4000mhz B die kit (already did, am I a bad person?) ready for the rumored 4000mhz IFs.

 

[lsevald]

You could also go with 4 sticks of RAM (if you haven't already), to get the benefits of rank interleave? Found some Ryzen 2 testing here:

Ryzen Above: Best Memory Settings for AMD's 3000 CPUs, Tested

Is Ryzen 3000 optimized for DDR4-3200? What if we want more? We examine everything from frequency to rank count to nail down optimal settings.

www.tomshardware.com

But as 4 sticks is more demanding on your RAM controller, you run the risk of having to drop RAM speed and/or increase timings. I don't know if 2 vs 4 sticks have any impact on IF stability, I'm guessing not, but don't listen to me, I'm going to build my first Ryzen 2 PC for a friend later today (3700x, b550 and 2x8GB 3600CL16 B-die RAM), so I'm taking a crash course in Ryzen tweaking now

 

[EarthDog]

I wouldn't go to 4 sticks... that will likely require a drop in bandwidth. Anything like that effects the IMC.

 

[lsevald]

Yes, I feel that the angle of that tom's article was a bit "artificially constructed", as they probably weren't at the limit of what their RAM could do with 2x8, but instead chose speeds and timings that would work for both 2x8 and 4x8 to isolate rank interleave performance benefits. But going from 2 to 4 sticks helped on my T-topology z390 board (crappy 4 layer PCB). It would barely train memory at anything higher than 3600, so with 4 sticks it unlocked speeds up to 4000 with the added benefit of rank interleave. At 3600 and 4 sticks, I had to up my timings a little from 14-15-15-x to 15-15-15-x, but that was easily mitigated by going up in speed. But now I'm contaminating a perfectly good Ryzen IF thread with Intel problems, sorry!

 

[leepox]

Doesn't help that the itx only has 2 slots for the ram

 

[Calmmo]

It should be better to go with dual rank sticks instead of 4 single rank ones.

 

[oxrufiioxo]

Some of the better binned B die can do 3800 13-13-13-28 and really low trc and trfc but you'll still only get to around stock 10600k performance in games so probably not worth it....

Assuming your CPU can do close to 1900 on the if this kit would get you about 90% of the way there as far as latency and you can probably get down to 62ns with it

G.SKILL Trident Z Neo Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3800 (PC4 30400) Desktop Memory Model F4-3800C14D-16GTZN - Newegg.com

Buy G.SKILL Trident Z Neo Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3800 (PC4 30400) Desktop Memory Model F4-3800C14D-16GTZN with fast shipping and top-rated customer service. Once you know, you Newegg!

www.newegg.com

This might also be a kit worth trying

G.SKILL Trident Z Neo Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3600 (PC4 28800) Desktop Memory Model F4-3600C14D-16GTZNB - Newegg.com

Buy G.SKILL Trident Z Neo Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3600 (PC4 28800) Desktop Memory Model F4-3600C14D-16GTZNB with fast shipping and top-rated customer service. Once you know, you Newegg!

www.newegg.com

I have the 4000 CL15 kit and its pretty damn awesome if somewhat pointless.... I use it on my Intel system though as it leverages it better than my 3900X would.

 

[leepox]

Thanks for the product share, was thinking of getting the patriot viper 4400 cl19. People are reporting cl14 timings when downclocked to 3600 without too much fuss. Am tempted to stick to b die and get a higher frequency one ready for the higher IF clocks on the 4000 series.

But yeah it's a bummer that the ryzen ipcs are so good but let down by that memory controller bottleneck and heavily penalises gaming performance!

 

[oxrufiioxo]

Yeah that's also a decent kit but its ugly and you'd be playing the lottery more than kits that are already doing CL14..... Though it's impossible to beat from a value standpoint.