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smithchrism
Adept II

What is boost on 3900x and when should it work?

Hello,

I purchased a Ryzen 9 3900x CPU 4-6 weeks ago along with a x570 motherboard and memory.  To refresh everyone's memory, its base speed is 3.8 Ghz with a boost of 4.6 Ghz on paper.  When I first setup and ran my system, everything reported I was getting up to 4.2 Ghz with system speeds fluctuating from 4.0 Ghz to about 4.2 Ghz.  I assume this is because of the "boost" of the CPU and motherboard doing its thing.

My motherboard came with its original BIOS being so new.  I immediately upgraded to the latest BIOS the board had which was the second released by the vendor at the time.  This BIOS is what I was using when I saw the above mentioned "boost" speeds.

Since then, there have been three BIOS updates from my board OEM, new chipset drivers, and new Windows updates.  My CPU is now running at 3.8 Ghz and appears to be unwilling to "boost" at all.  This started 3-4 weeks ago I guess but I'm not sure.  The only way I can get my system to run faster is if I purposefully overclock it with Dragon Center by selecting the "Extreme" Option.  I also downloaded and ran the Ryzen Master utility.  It appears I can enable the boost of the CPU by entering creators mode and applying the precision boost option.  However, when I reboot the system this goes away and I have to run the software.

I'm beginning to wonder: what exactly is "boost" and when it the speeds of the CPU speed boost up?  I was under the impression the user didn't have to do anything.  The system would boost CPU speeds up to 4.6 Ghz if it felt it could.  This appears to be no longer happening.  Is it possible I have disabled boost somehow?  Is it possible I can reenable boost in the BIOS and if so where?  I could probably overclock my system and make it run at 4.2 Ghz.  However, if the system gets hot for some reason it won't back off automatically i.e. it would permanently be stuck at 4.2 Ghz.   prefer my system speed ramp up and down based on conditions without requiring various utilities to run and stay in the background all the time.

Thanks,

Chris Smith

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6 Replies

As you have tried an overclock I would rest your BIOS firstly to get back to default settings.

This won't affect the BIOS version, it will only set everything back to the manufacturer's defaults.

Take the CMOS battery out, short the CLR CMOS jumper with a small screwdriver, wait 1 minute then put the battery back in.

Then go into your BIOS and check that PBO (Precision Boost Overdrive) is set to enabled as this allows your CPU to boost.

The boost is a feature that enables the CPU to reach its maximum speed, 4.6 GHZ in your case, under load.

This is only for single core performance though and so all core boost will be slightly lower.

I found with my Ryzen 3700x if I overclocked it then it would stop boosting until I reset the BIOS so hopefully this will help to sort yours out.

Andy

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Thanks for the response cosmicdance.

I like your thinking.  I have seen things when I first set my system up where it seemed like there was a problem.  I just unplugged the system for 2-3 minutes and everything cleared up.  I have tried that yet regarding my question of boosting and lackthereof.

If that doesn't do anything, I'll do like you said: reset everything, remove battery and short the CMOS jumper, wait a bit then boot back up.

Thanks for the thoughts.  I'll try to keep you posted.

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ajlueke
Grandmaster

Hello!

There can be some confusion based on similar terminology used by AMD.  If "Core Performance Boost" is disabled in UEFI, your CPU will not boost at all.  This is different than "Precision boost overdrive" which is not required for normal boosting.

Also, any changed either in the UEFI or via software that puts the CPU in "OC-mode" breaks boosting.  If you change BCLK, or manually set CPU voltage, all boosting will be disabled.

My advice would be to uninstall the Dragon center/Ryzen master and then load "optimized defaults" in UEFI.  Just clearing CMOS doesn't always clear values out of the "AMD Overclocking" section, you have to load the defaults.  Verify that boost is working and then add your software back in. 

In Windows many are reporting to use the "Windows Balanced Power Plan" Not any of they Ryzen power plans for best boost efficiency as well.

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smithchrism
Adept II

Hi fellas,

I'm not sure what did it but everything is working now!

The bad thing is I'm not 100% sure how.  I used  Ryzen Master first and RESET everything back to defaults.  When I did this everything worked again until I rebooted.  

Frustrated, I then completely uninstalled Dragon Center and rebooted again.  Again, I went to Ryzen Master and RESET everything back to default.  Doing this, the CPU started to boost again like last time.

This time I shut the computer down and unplugged the computer.  It ended up being unplugged for 10 minutes or so.  I did this because I have seen times in the past when I made changes they did not take until I did that.

This time, when I rebooted the computer, the CPU cores still boosted as I expected.

Like I said, I'm still scratching my head a bit.  But, the end result is everything [appears] to be working fine and correctly.

Thanks for the thoughts fellas,

Chris Smith

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The difference in startup one working and another not could be the Windows Fast Startup feature. It is know to introduce "old cached settings" even after you have changed them. If you continue to see problems you might want to disable fast startup and see if that helps.

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