Is my CPU being throttled or is the motherboard's VRM causing it?
Is my CPU being throttled or is the motherboard's VRM causing it?
In short, about a week back my PC began having trouble running the games I normally play at the settings I used. I’ve also noticed occasional 1% frame drops that last around a second, which happens quite often. This change happened suddenly and without warning. The biggest factor linked to those frame drops is my CPU usage reaching 100%.
Here are my specs:
CPU: AMD Ryzen 7 5800X3D
MB: MSI b450M Pro-BDH MAX Micro ATX AM4
Ram: CORSAIR VENGEANCE LPX 32GB 2x16GB DDR4 3600MH
Storage: Samsung SSD 870 EVO 1TB and 2TB
Graphics: ASUS Dual GeForce RTX 4070 SUPER
PSU: Corsair RM850x (2021) 850 W
What I’ve tried so far:
First, I thought it might be a Windows or GPU update, but there hadn’t been any updates for weeks before the problem started.
Next, I checked my cooling setup—my case fans were failing, and my CPU was regularly hitting 90°C. I replaced the case, added water cooling, and installed six fans, but the issue persisted. Neither CPU nor GPU exceeded 70°C in the new configuration.
Then I went through all software fixes: updated drivers, BIOS updates, performed a full Windows reset, and formatted my SSDs.
I also tested running the same games on each SSD to see if one was faulty, but both had the same issue.
Ensured RAM speed wasn’t throttled, increased graphics settings in games, used DDU for GPU drivers, set power mode to highest performance, checked cables and GPU connections, and verified XMP mode in BIOS.
This machine was originally a prebuilt unit; everything except the motherboard has been replaced.
I’ve asked forums for advice, and some suggested my motherboard might be throttling CPU performance—possibly due to budget constraints. I checked MB temperatures, but nothing alarming. There’s a warning in BIOS about CPU power limits: 105W CPUs can reach 100A, suggesting pairing with lower draw CPUs.
My CPU TDP is 105W with typical loads between 45–80W, but it spikes up to 114W under heavy use.
The motherboard also seems to have VRM issues, especially when paired with the 5800X3D. I’m concerned that prolonged overheating might have damaged the motherboard, though I haven’t seen any visible damage after moving everything into a new case.
I’ve attached images of the lag spikes in games. They appear during loading and while playing normally. What confuses me even more is that I can no longer run games at my usual settings. Previously, I could play at ultra or high without issues, but now I’m forced to lower settings significantly, experiencing much lower FPS and still seeing those lag spikes.
A friend suggested running a passmark benchmark, which I’ve shared here too.
Please, any advice would be greatly appreciated. I’ve been struggling for about a week, and my budget is tight—any guidance on whether to upgrade the motherboard would be invaluable.
That's true, since your MoBo seems to have 4+2+1 VRM conf, which, for mere 4 main vcore phases, is bottom of the barrel when it comes to VRM.
And with no cooling on chokes what-so-ever. Some mosfets seem to have heatsink but not all of them.
Before going with new MoBo, there is one, last ditch effort to do:
Format OS drive and make a clean Win install.
This will get rid of all software issues. If issues still are present, looking to better MoBo would be good idea.
But if issues go away, you're golden and saved some money.
As for new MoBo, one of the best would be this Asus X470,
specs:
https://rog.asus.com/motherboards/rog-cr...ero-model/
It has 10+1+1 VRM conf (10 vcore, 1 vgpu, 1 for the rest of the system).
You can tell the VRM phase amount by counting the small square items around the CPU socket. Those are VRM chokes and usually, there is one choke per one phase. And one or two (sometimes three) chokes are always reserved for the rest of the system. So, total chokes amount, minus 2-3 chokes = VRM phase amount for CPU alone. Usually, for CPU, there is even number of VRM phases. So, when there would be e.g 8 chokes on the board, the VRM conf could be either 6+2, 6+1+1 or rarely, 7+1.
Swapped the motherboard and performed a clean Windows installation, but no problems were resolved.
Remove XMP and check if it helps. Also, download and run memtest86, using the provided link. Follow the installation guide at the given URL. A single full pass takes about 1 hour for 8GB RAM, around 4 hours for four passes, and longer with higher RAM. Two full passes are better than one, but four is still acceptable. Run it overnight for best results. If no errors appear, your RAM is in good condition. Errors indicate faulty RAM, which can be replaced. Sometimes RAM generates errors when XMP is active; once disabled and running at JEDEC speeds, errors disappear in memtest86. For thorough testing, perform 32 full passes (as suggested by test #7), though most users stop after four due to time constraints, especially with large amounts of RAM. The recommended number remains four full passes. What is your monitor refresh rate? And what is your average FPS while playing games?
Why is your main memory so heavily shared with the GPU?!?!
Are you running at 4k with ultra texture packs?!
The 12Gb on board GPU RAM should be more than enough for everything.
Maybe it's just the swapping happening between this shared RAM that leads to the stutters.
True.
I just read an article discussing various RAM configurations tested in games, linked here: https://www.techspot.com/review/3076-how-much-ram-2026/.
32GB of RAM is sufficient, but with 16GB, the remaining space is often shared with the GPU, which can lead to problems in certain titles.
Switched to a MSI B550 Tomahawk with maximum Wi-Fi
Usage varies by game and configuration. For Arc Raiders, I used all settings and achieved over 160 FPS, while Marvel rivals ran at 180+ with full settings. I lowered Arc Raiders to high and now get around 100 FPS, and reduced rivals to medium for a cap of 165.
Refresh rate is fixed at 165 on both displays.