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ajlueke
Grandmaster

Re: Ryzen 9 3900X Boost Frequency

This is the danger with having fast and slow cores.  To have the same performance as a processor with all fast cores, there is now software overhead that needs to load the correct cores at the correct time.  That is definitely not working correctly currently.

On the plus side, I was able to clock my 4X8 GB kit of RAM at 3600 CL16 relatively easily and keep the fabric clock at 1800 MHz as well.  All core boosting seems to work just fine.  At my EDC limit of 145A I was using about 1.4V sustained on the CPU for a clock speed of 4.13 GHz on all cores.  

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s_vayner
Adept III

Re: Ryzen 9 3900X Boost Frequency

This is my update after latest agesa aab release for my motherboard. After tweaking it and trying every possible combination of settings i was able to get my processor to boost to 4.5 on single and around 4.1 on multi. i think at this point this is as good as it will ever get. If anyone has Prime x570 Pro board these are the settings that will get you most performance, at least from my experience. 

1. Install latest BIOS, Chipset Driver, set power profile to AMD Balanced, Load defaults in bios.

2. make sure memory and infinity fabric is 1:1 ratio. Keep it on Auto if memory is at or below DDR3600

3. set CPU v-core to offset mode and set offset to around (negative) -0.05v. You can try values between -.025 and -.075 (at -0.075 you might get better boost but CPU may become unstable)

4. Enable all 3 PBO boosts in BIOS. One in AI Tweaker, One in AMD Overclock and one in AMD CBS (the last one is buried really deep in bios somewhere) i have trouble finding it every time. Keep everything on AUTO except setting PBO to Enabled.

With those settings i was able to get CB20 multicore to 7212 and single core to 519. I hope this could help someone with similar issues.

brucer
Forerunner

Re: Ryzen 9 3900X Boost Frequency

if your fclk and memclk are different there is an issue with the memory controller and it degrades performance.. I seen this on a buildzoid video..

brucer
Forerunner

Re: Ryzen 9 3900X Boost Frequency

my 3800x will do 4.4 all core stable  at 1.4v,  at default settings I will hit boost clocks, but its random across 3 different cores, and my fastest core according to Ryzen Master is ccx #6 yet it never hits the max boost clock, its either 1, 3 or 5 that hits it..

shinkojiro
Miniboss

Re: Ryzen 9 3900X Boost Frequency

The listed boost frequency was never all-core so that should come as a surprise. No matter how many times people like Steve from Gamers nexus try to squash that misconception, people seem to still expect that...

What should be expected is single core tasks reach, and maintain, this advertised boost speed, which is what isn't happening. I'm not going to be one that says its the processor or AMD lied, because its neither as the speed will actually be maintained if you set it with a manual OC.

shinkojiro
Miniboss

Re: Ryzen 9 3900X Boost Frequency

Can you verify the same Single core score if you use a manual OC and use Ryzen master to set the speed of CCX0 to the rated boost speed?

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shinkojiro
Miniboss

Re: Ryzen 9 3900X Boost Frequency

Primary problem with Manual OC is too many people are scarred to go passed 1.35v as there is a maddening misconception that 1.325 is the safe voltage. If it were, AMD would never have default voltages so close to 1.5v.

My 3900x too does 4.4ghz at 1.4v all core stable, and achieves the same single core score I would if leave it to PB2/PBO.

What you should be able to do is use Ryzen master to set CCX0 preferrably to 4.5ghz, which may require a bit more voltage, and Check your single core score against what you would get with stock settings. This is what I am doing Currently:2019.08.20-11.31.png

Increases score from 205 to 216, showing that a manual clock actually reaches and maintains the speeds.

s_vayner
Adept III

Re: Ryzen 9 3900X Boost Frequency

i dont want to experiment with OC. These CPUs have no OC headroom and that core only barely sustains 4.5ghz for a few seconds. running it  locked at 4.6ghz will probably damage it.

shinkojiro
Miniboss

Re: Ryzen 9 3900X Boost Frequency

I guess you'll be stuck with what you got until AMD adjust the algorithm in AGESA updates.

shinkojiro
Miniboss

Re: Ryzen 9 3900X Boost Frequency

Thats the almost the same speed I get with mine, 4544mhz. However, its really not just about seeing a reading close to the boost speed, its maintaining that speed through a single core load as well which isnt happening.

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