So, here's something weird with my 3900X...

Discussion created by jeffb0918 on Oct 19, 2019
Latest reply on Mar 22, 2020 by candymancan

Computer Type: Desktop custom built (by me)


CPU: AMD Ryzen 9 3900X 12-Core Processor (Default, except FCLK at 1800MHz for memory OC at 3600MHz)

CPU Cooler: Cooler Master Masterliquid 240

Motherboard: ROG STRIX X570-F GAMING

RAM: Corsair Dominator Platinum 2x16GB 2800MHz DDR4 Samsung B-die module (CMD32GX4M2A2800C16)

PSU: Seasonic Prime Snow Silent 750W 80+ Platinum

Operating System & Version: Windows 10 Pro 64-bit Build 18362

GPU Drivers: GeForce 436.48

Chipset Drivers: (taken from AMD's website, as I can't figure out how to check this in my system)

Background Applications: Cinebench R15, Cinebench R20, Ryzen Master, HWInfo

Description of Original Problem and Troubleshooting:

About 2 weeks ago I decided to finally switch from Intel to AMD. I picked up a 3900X paired with the ASUS RoG X570 Strix-F motherboard and 2x16GB Corsair Dominator Platinum 2800MHz DDR4 kit with Samsung B-die modules. All went well, and after finishing the build, I immediately updated the BIOS to the latest available on ASUS's website, which is 1201 and this includes the ABBA AGESA update. I then also grabbed all of the necessary drivers, software suites, etc, Ryzen Master, and the chipset driver from AMD's website. I benchmarked the system and started overclocking my memory to 3600MHz with just 1usmus' DRAM calculator. These all went perfectly fine for me.

It was at this moment that I found out about the Ryzen 3000 boosting issue from Der8auer's video and from what I can gather the ABBA AGESA was supposed to somewhat mitigate this boosting issue. This intrigues me and I get to benchmarking the system matching Der8auer's polling requirement, just to see where my 3900X lies in Der8auer's distribution curve. I did the R15 single-core benchmark, with HWInfo for monitoring, clock speed monitoring only, 500ms polling, and no PBO. So, basically, the only change I have in BIOS at this point is just those related to my memory overclocking at 3600MHz and 1800MHz FCLK to run it at a 1:1 ratio. Now, I was quite happy with the result, as I was able to see in HWInfo, with R15, that my maximum boost during the single-core benchmark reached 4.5917GHz. For the sake of curiosity, I then tried the same thing with R20, and I was even more surprised since the maximum boost clock during the benchmark is 4.6167GHz. I repeated this many many times at the time and the results were consistent. That is to say that I can keep hitting 4.5917GHz and 4.6167GHz boost clocks in R15 and R20 single-core benchmark respectively.

Now, this is where things get weird for me and my understanding of the CPU behavior began to break down. Pretty much a week later up to the writing of this post, I occasionally randomly benchmarked the system with both R15 and R20, and I was unable to reach the same maximum boost clock in HWInfo. These are also reflected by the marginally low Cinebench score. I again repeated this many many times, and up to the writing of this post, the behavior is also consistent, in that, the 4.5917GHz and 4.6167GHz boost clocks are nowhere to be found. Now, the point of this post is to seek help in understanding why this is happening, what's wrong or if there's anything wrong with either my CPU, motherboard, memory, driver, BIOS, Windows version, monitoring software, or God knows what. I am completely lost now, and that's why I decided to post this here.

Do note that I have not changed anything in BIOS or in any other settings application, Ryzen Master or ASUS's AISuite, ever since I started benchmarking with R15 and R20 after seeing Der8auer's video. If anyone would like to see the "proof" for the 4.5917GHz and 4.6167GHz boost clocks, I can try and post the screenshots I took of it here.

If anyone knows or understands anything regarding this, in my opinion, strange behavior of the 3900X, do let me know! Any help would be appreciated! Thanks in advance!