[SOLVED] PC turns off on all core load after CPU upgrade

[RcCookie]

I recently upgraded my Ryzen 5 4650g to a 5950x. Ever since the PC has been turning off when under heavy CPU load, but not perfectly consistently (not a problem before). When it turns off, the rgb and the fans stay on. Sometimes it reboots, but most times nothing helps but turning the PSU off and back on again (not holding the power button, nor the hard reset button).

My specs are:

• Asrock B550m Pro 4
• Ryzen 9 5950x
• Cooler Master 212 Evo
• MSI 3070 Suprim X
• 2x16GB@3200 & 2x8GB@3600 Crutial Ballistix
• Corsair RM750

I am aware of the fact that the 212 Evo is not really enough to properly cool the 5950x, and an upgrade is planned. However, this doesn’t seem to be the problem. The PC also crashes when the CPU is not overclocked, running at ~3800mhz under all core load, with <70°C.

Interestingly, when I first installed the new CPU, it used to run @~4500mhz under all core load, eventually throttling down to ~4000mhz, but always running at the 90°C thermal limit, and using ~150W. It used to crash there as well, but not too regularly, I managed to run a 10 minute Cinebench run just fine. Since then I have updated my bios to the latest version, installed new chipset drivers and Ryzen Master. I am not sure what of these made the difference, but now the CPU is immediately throttling to 3800mhz as soon as there is an all core workload, even though it then hovers around 62°C, with an average power draw of 120W. Like this it also doesn't crash during a Cinebench run, but still during gaming like previously (I like playing BeamNG.drive, that does stress all CPU cores).

I have been playing around with Ryzen master, and what I noticed that both AutoOC and manual overlocking cause a quicker crash. For AutoOC lowering the power draw limit seems to make it more stable, but at 150W it is still crashing during Cinebench unlike before. Manual overclocking has similar effects, even just a constant frequency of 4100mhz causes a crash during Cinebench.

A quick conclusion over what I've tried without any success:

• Clear bios
• Update bios
• Update chipset drivers
• Windows (11) is up to date
• Run with only one type of RAM
• Check Windows event viewer: critical error 'Kernel-Power' with id 41 (didn't find anything useful online)

So I wonder: what could be the problem? I thought maybe its the PSU, but then everything should power off at once, right? Like I said, the fans keep spinning, as does the RGB stay on, and besides, even if the GPU was to draw 400W and the CPU 250W, which is not even remotely the case, the 750W PSU should be fine.

My last two guesses are either a CPU failure itself, or maybe the mainboard? I am not very familiar with power phases and that stuff, however, based on OpenHardwareMonitor the mainboard components never pass 65°C, even when forcing a power draw of >170W using manual overclocking. However, it is only a B550, so if there is a realistic chance that that is the point of failure, I will replace it with an X570. However, I can't really affort spending money on multiple components right now, that would mean the AIO had to wait.

 

[RcCookie]

ADDED: and I just noted something that's curious since the system is supposedly in full default after a CMOS reset: it's using a 1600Mhz IF clock so 3200Mtps memory. It's more normal to see 2133 or 2400 default DDR4 memory settings after a CMOS reset.

Yes, I have since the reset applied a "slow" XMP profile again, and adjusted the fan curves.

 

[RcCookie]

It's hard to say for certain but I still wonder if VRM is throttling the CPU. If you have an IR thermometer handy I'd check temps all around it while running Cinebench. Especially the capacitors.

I'll see if I can find one, but keep in mind the Pro4 has a pretty big heatsink across the VRMs so you won't see much there

 

[drea.drechsler]

I'll see if I can find one, but keep in mind the Pro4 has a pretty big heatsink across the VRMs so you won't see much there

Yeah that's why you beam on the caps and coils, even if not the FET's they also get really hot. But if you can get to the backside of the board also beam on the bottom right where the FET's are located. That's going to probably be the best indicator since you can look at each FET on the backside: if you find one stone cold then it's blown.

BTW: ignore the two Vsoc phases as they're not heavily loaded with a CPU. It's the three VCore phases... at least I believe it's three true phases with doubled current paths on a Pro 4 board. They call it 6 phases but that's not true, independently controlled phases.

 

[drea.drechsler]

Yes, I have since the reset applied a "slow" XMP profile again, and adjusted the fan curves.

I must say...this motherboard behaves strange to me. I'd want a CMOS reset to result in the most stable configuration possible and that means only using a default DDR4 profile and no XMP profiles.

 

[RcCookie]

I must say...this motherboard behaves strange to me. I'd want a CMOS reset to result in the most stable configuration possible and that means only using a default DDR4 profile and no XMP profiles.

No, I think you misunderstood. I cleared the CMOS, ran a few tests, then went into the bios and modified the fan curves, together with the XMP settings. I have previously tested if the RAM was the problem, maybe because of the mix, even though it was working fine before, but it wasn't the issue.

 

[RcCookie]

Yeah that's why you beam on the caps and coils, even if not the FET's they also get really hot. But if you can get to the backside of the board also beam on the bottom right where the FET's are located. That's going to probably be the best indicator since you can look at each FET on the backside: if you find one stone cold then it's blown.

BTW: ignore the two Vsoc phases as they're not heavily loaded with a CPU. It's the three VCore phases... at least I believe it's three true phases with doubled current paths on a Pro 4 board. They call it 6 phases but that's not true, independently controlled phases.

So, something does indeed not seem quite right here. I suppose the vsoc phases are the 2 that are horizontally placed and not under the heat sink (?). The tip with measuring from the rear was really good, because I couldn't see anything from the front because of the cooler fans + heatsink.

Temps for the given areas:

1. 85-90°C
2. 70-75°C
3. 50-55°C
4. 40-45°C
5. 30-35°C

All temps under full load. You could start to think only the top VRM is working??

 

[drea.drechsler]

So, something does indeed not seem quite right here. I suppose the vsoc phases are the 2 that are horizontally placed and not under the heat sink (?). The tip with measuring from the rear was really good, because I couldn't see anything from the front because of the cooler fans + heatsink.

Temps for the given areas:

1. 85-90°C
2. 70-75°C
3. 50-55°C
4. 40-45°C
5. 30-35°C

All temps under full load. You could start to think only the top VRM is working??

You are right about the uncovered FET's being the Vsoc VRM.

Circled areas 1, 2 and 3 are the VRM phases: you can tell by counting the square solder pads, there are 6. Those are where one lead of the inductor is soldered in; the other lead is to it's left on a diagonal. There are 6 such pairs, one for each phase's inductor.

Phase 5/6 ( circle number 3 in the image) is still quite low temp for powering a 16 core CPU that's (supposedly) working it's heart out, and phases 1/2 are very hot considering you're not directly reading the FETs but the bottom of the board with an IR thermometer. While I don't have a baseline for that board to be positive it looks to me like something's very much not right with the VRM. If you could get a temp reading close to the FET itself on the motherboard then it could easily be over 100C, maybe even approaching a typical throttling temp around 115-120C.

Also: it appears there may be a doubler for each phase, if so that would be a properly phase doubled VRM at least. But it seems to be seriously inadequate for a 5950X CPU even so. A damaged VRM is not delivering clean power and that leads to CPU instability, i.e., crashes.

 

[RcCookie]

So I've ordered a new mainboard - Asus rog strix B550-f gaming - any thoughts on that? I've watched a comparison of several B550 mainboards by Hardware Unboxed, it performed really well for its adequate price. It's a little old so they only tested it with an overclocked 3950x, but as it could handle that pretty easily I would think that even a slightly overclocked 5950x, and particularly a stock one, shouldn't be a problem. I also looked at some X570 boards, but for this price (I paied 150€) there is really not much that can compare in terms of VRM design, as you're paying more just for the better chipset which I don't really need.

I've also reinstalled Windows. So far no crashes after the reset, but I haven't done any stress test and probably won't to avoid damaging the current (old) mainboard more, in case it already is, in the hope that it will still run fine with the previous processor.

 

[RcCookie]

So, just wanted to post this in case anyone has similar issues and finds this thread, the new mainboard did in fact solve all the instability issues. Furthermore, with PBO enabled the CPU now boosts to its thermal limit again, without any "spiky" performance drops resulting in worse performance. Particularly, the somewhat insufficient cooling was not an issue. As a sidenote, the 5950x runs perfectly stable and at <75° when running stock power limits, so you can in fact, even if you leave some performance on the table, run it with a 212 Evo.