Processors

[Coltaine]

Heyo,
I recently upgraded from a Ryzen 5 3600x to a Ryzen 7 5800x3D, mostly for better performance in WoW, but so far I am pretty disappointed. I am using an old Asus Prime B450-Plus mobo, a 6900xt GPU and 2x16GB 3200Mhz Kingston Fury RAM Sticks.
I've been trying to tweak stuff using PBO2 and OCCT for testing, and I've noticed the following:
- without reducing the Voltage limits my CPU stays at 90C during stress tests. The Clock speed averages are around 3.9Ghz, and they barely ever go above 4100
- with the limits in PBO set to 120, 75, 110, the CPU runs at 80-82C during stress testing, but there is not much improvement to clock speeds.
I am using a Deepcool AK620 cooler which has really good reviews from what I've found. What I noticed is that after about an hour of stress test in which the CPU is theoretically running really hot (80-90C) the heatsinks of the cooler are barely warm, which seems a bit odd. I already cleaned up the thermal paste and re-applied it, thinking maybe I used to much at first, but it does not seem to have helped.
I've also noticed that there is a heatsink on the mobo right next to the CPU (I think it's for some VRMs, but I'm no expert) which gets really hot (it's even quite hot while idling).
Does anyone have any suggestion on what might be wrong with my system?

Here are screenshots taken during the OCCT Test, while undervolted with PBO2 (-25 on all cores, and PPT TDC EDC at 120W, 75A, 110A):

Is there a world in which my old mobo is causing these issues?
Any advice is highly appreciated!!!

[FunkZ]

Looking at your Ryzen Master screenshot I noticed a few things.

One it's showing Curve Optimizer is off, and it's also missing the Curve Optimizer tab on the left, yet you state you are applying -25 on all cores. Make sure you have updated the BIOS to the latest version available. Curve Optimizer is "PBO2" which requires 1.1.8.0 AGESA or higher.

Two it's showing only 1.07V which is very low, it could be due to the reduced PBO limits you have set, or it may be simply the Auto voltage given the reduced clock speed of 3.8GHz. On the other hand, the Asus Prime B450-Plus is only a 4+2 phase VRM which is very weak, and you state the VRM heatsinks are very hot, so it could easily be the motherboard restricting the CPU.

[Coltaine]

Thanks for the reply!

My BIOS has been updated to the latest version a couple of days ago. I wasn't aware there is a curve optimizer available in Ryzen master, I was just using PBO2 Tuner for undervolting, as explained here: https://github.com/PrimeO7/How-to-undervolt-AMD-RYZEN-5800X3D-Guide-with-PBO2-Tuner/blob/main/README...

I think my motherboard might be too old to support Curve optimizer natively, I am not sure.

So your opinion is that mobo could actually hinder my CPUs performance?

Cheers!

[FunkZ]

Not sure why someone would use 3rd party software on public Github that frankly looks sketchy, and apparently doesn't work anyway as your Ryzen Master screenshot clearly shows CO - Off.

PBO2 functionality (Curve Optimizer) is available natively in the BIOS and through Ryzen Master. I don't know what that Github software is doing, but I certainly wouldn't trust it.

ASUS Prime boards are very bare bones.

[misterj]

Super, FunkZ!

[Coltaine]

The reason I'm using this software is because I can't enable curve optimizer in BIOS. I've looked everywhere and cannot find it.

I guess it's just not available for B450 mobos for the 5800x3D. (I have the latest BIOS version).

Apparently this problem is quite common and this software is what many people use to get around it.

It does work, if you look in Ryzen master you will see the PPT, TDC and EDC are lower than defaults.

Anyway, I think my main issue is that even with undervolting my CPU still goes to 90C during stress testing.

For example I got a 13768 Multi-core score in Cinebench R23. People with the same CPU are managing to get over 15k with temperatures not reaching 85C.

My cooler is good, theoretically, and I've remounted it 3 times (last time it led to a ~2C decrease in average temps).

I'm really not sure what's going on, I don't really think the mobo can cause the CPU to overheat faster, can it?

Could it be that I am unlucky and I just got a sub-par CPU chip?

[FunkZ]

Power limits (PPT, TDC, EDC) were part of PBO, Curve Optimizer was introduced in PBO2. These features perform separate functions.

https://community.amd.com/t5/general-discussions/amd-introduces-precision-boost-overdrive-2/td-p/424...

Your power limits of 120W/75A/110A are I believe lower values than stock for a 5800X3D as most 105W TDP processors are 142W/95A/140A. However the fact that limits are set lower is NOT an indication that Curve Optimizer has been enabled. As stated above Curve Optimizer is a separate feature apart from power limits that can be enabled to apply from +30 to -30 offset to power curve. Power limits set a ceiling for the processor operating range whereby PB Precision Boost will automatically stop increasing clock frequency when a limit is reached.

Lower power limits WILL result in lower clock speed as it is restricting how high PB will allow frequency boost. Lower CO typically results in higher clock speed as using less voltage reduces power draw and heat allowing PB to boost more.

[johnnyenglish]

I'll back up on the @FunkZ board statement. 4+2 is just not enough to keep it happy.

PBO works best while headroom is made available, and VRM current is one of them.

Image for the added drama

[Coltaine]

Hi and thanks for your reply!

Do you have any idea if weak VRMs can lead to faster/worse overheating of the CPU itself?

As mentioned before, under stress tests my CPU goes to 90C and gets throttled, and i've been reading a lot of posts on reddit of people saying theirs doesn't reach 85 (sometimes not even 80) during the same tests, and with the same or similar undervolting. (which also leads to them getting better scores, since their CPU doesnt thermally throttle as bad as mine). The only really noticeable difference between their systems and mine (some have liquid cooling, but others with air cooling similar to mine still report good results) seems to be the motherboard. They usually have B550s or better, and mine is on the lower end of the "acceptable" spectrum.

I might just order a B550 Tomahawk and give it a go, and if there is no improvement I can hopefully return it.

Any advice is welcome!

[gto_pro]

u should deactivate PBO and overclock the cpu manualy to maybe 4.5 ghz wich is the max that it can go and play with the voltages till u get the lowest possible  cause with pbo the voltages are maxed out and thats where most of the heat comes from.

[FunkZ]

The 5800X3D doesn't support manual overclock frequency. It is limited to using PBO2. (Power Limits and Curve Optimizer)