3900X Running Below Base Clock

[r0otctrl]

I just finished building my "new" PC with the 3900X.

 

Why does the CPU or a handful of cores sometimes run at speeds below the base clock of 3.8GHz?

 

P.S. For some reason it is not letting me upload a screenshot? "-200" error?

 

[Senzelian]

To safe power, because they're aren't always needed.

[themctipers]

it lowers it's clockspeed to save power, same thing happens on my 3600 and my 8350u laptop

use ryzen master to see which cores are parked/deep sleep 

[r0otctrl]

Okay, thanks guys. I just wanted to make sure nothing was wrong, like a lack of power. I'm cutting it real close with my 650W PSU.

[r0otctrl]

2 minutes ago, themctipers said:

it lowers it's clockspeed to save power, same thing happens on my 3600 and my 8350u laptop

use ryzen master to see which cores are parked/deep sleep 

It really dips below base clock speeds to save power though?

[themctipers]

2 minutes ago, r0otctrl said:

It really dips below base clock speeds to save power though?

yea, why would it not?

[r0otctrl]

2 minutes ago, themctipers said:

yea, why would it not?

IDK. I just know that my old i5-4690k would never drop below the base clock speed? Maybe because the chip wasn't powerful enough?

[themctipers]

Just now, r0otctrl said:

IDK. I just know that my old i5-4690k would never drop below the base clock speed? Maybe because the chip wasn't powerful enough?

my 3770k lived it's life almost always overclocked for me so I have no idea how it would do under stock, but it never dipped below my overclock (4.4GHz, never anything less)

my laptops would always drop under base clock though to save power though, even on AC (core 2 duo t7600, i5 540m, i5 2410m, i5 8350u)

[r0otctrl]

3 minutes ago, themctipers said:

my 3770k lived it's life almost always overclocked for me so I have no idea how it would do under stock, but it never dipped below my overclock (4.4GHz, never anything less)

my laptops would always drop under base clock though to save power though, even on AC (core 2 duo t7600, i5 540m, i5 2410m, i5 8350u)

Strange. I guess I'll keep an eye on it. Anyways, thanks for the info!

Btw, do you know any good RAM overclocking tutorials for a complete beginner?

[DoctorNick]

All cpu's do that unless you disable this feature. If you manually overclock the multiplier or baseclock and leave everything else on auto, most motherboards will lock to the highest multicore clock. I always do it the other way around and enable all power saving features, even when overclocking to save power, and limit the heat output of the PC. Because wasting energy is a waste

[XHT_001]

to keep the silicon within the operating temperature, which has a maximum temperature of 95c https://www.amd.com/en/products/cpu/amd-ryzen-9-3900x

 

with power and heat having a 5-10% varient and some random math, as far as the R6 2600 goes

 

normally on a 2600, if the silicon temperature is 80-85c. then the cores run at full speed, anything above, the core's throttle

[r0otctrl]

1 hour ago, DoctorNick said:

All cpu's do that unless you disable this feature. If you manually overclock the multiplier or baseclock and leave everything else on auto, most motherboards will lock to the highest multicore clock. I always do it the other way around and enable all power saving features, even when overclocking to save power, and limit the heat output of the PC. Because wasting energy is a waste

I know there's an option somewhere in windows that prevents the CPU from "clocking down" (or "clocking out" lol). When I did this with my last CPU, it locked all of the cores at the boost speed.

Agree with everything you've said. Just wanted to make sure nothing was wrong with my chip 

[themctipers]

11 hours ago, r0otctrl said:

Strange. I guess I'll keep an eye on it. Anyways, thanks for the info!

Btw, do you know any good RAM overclocking tutorials for a complete beginner?

What die do you have? Download thaiphoon burner and check

 

Edit: google everything tbh when it comes to memory overclocking. I'm having fun with mine right now and there's a lot of goodies / tricks that isn't all on one website, but rather scattered across the internet 

buildzoid is a great resource though

 

the first thing I recommend is finding your maximum fCLK (infinity fabric) overclock as well as your maximum CPU undervolt (let PBO do the overclocking, that's what I heard was the best/easy method)

run XMP and do a memtest for a hour or two, if it's stable at that fCLK with both a memory stress test (XMP default) and a prime95 AVX test then start tinkering with ram 

(you want to stress memory and CPU because infinity fabric does two things: CCX to CCX communication and CCX to memory communication)

 

assuming you have a good ram kit, see if you can match it up 1:1 fCLK and mCLK (memory speed, remember it's /2 because DDR. eg, DDR4 3200 is actually running at 1600MHz)

it's not worth desync for fCLK and mCLK if the difference is <133MHz , but it's worth it if it's over (eg, running DDR4 3200 with a 1833 fCLK is worth it, but running DDR4 3600 with a 1800 fCLK is better than running 3600 and 1833)

 

maximum safe voltage for ddr4 is 1.45v. Bump your ram to 1,45v for the remainder of the overclock to figure out what's the fastest/tightest configuration 

 

I'd start off with running ryzen memory calculator and using those numbers as a beginning start, then tightening up the values. Only enter in the primaries (CAS, tRCD, tRP, tRAS) and then stress for a bit

then lower the numbers down.

 

Once you've lowered CAS, tRCD, tRP and tRAS down to as low as it'll go while being stable, try tweaking with tRC

minimum tRC value = tRP + tRAS

 

Once stable, put in the tertiary timings from the ryzen calculator

i have no idea what to do at this point as I'm starting this point right now.. memory overclocking will take you a good while though. I recommend 8hrs stress test as the ambient temperature of the ram itself will affect stability 

[MadmanRB]

13 hours ago, r0otctrl said:

Okay, thanks guys. I just wanted to make sure nothing was wrong, like a lack of power. I'm cutting it real close with my 650W PSU.

nah 650w is more then enough wattage for your rig, Zen2 is very power efficient.

[r0otctrl]

On 9/6/2019 at 2:52 AM, MadmanRB said:

nah 650w is more then enough wattage for your rig, Zen2 is very power efficient.

 

im cutting it real close with about 50w to spare, at least according to the estimates on pcpartspicker, but who knows how accurate that is

[Dodge Gee]

Hi Guys. How do you stop the CPU clocking below base clock? Do you disable global c states? I have a 3800X and jumps between 3.6 and 4.5GHz. I wandering if I could get it to stay at base of 3.9 and boost to 4.5Ghz if this would result in extra performance