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I believe on my Asus ROG Strix X470 and B550 motherboards, it was enabled by default.PBO is not active by default. It's not hard to check anyway, just load up something like Prime95 and monitor PPT. If it's 142W then you're running bone stock.
PBO auto = disabled. And even if it is enabled in some way, it basically do nothing, other than expand power/current limits for your cpu, assuming other settings stay untouched (boost, curve, scalar and thermal limit).I currently have all of the PBO stuff set to "Auto". Maybe I should change it to "Disabled" then.
PBO auto = disabled. And even if it is enabled in some way, it basically do nothing, other than expand power/current limits for your cpu, assuming other settings stay untouched (boost, curve, scalar and thermal limit).
The reboots itself are actually two separate issues. And the reasons for it depends on whether it happens at idle or under some load (i.e. games or rendering).
IMO, most probable are:
1. Defective sample. If reboots happen with the default CPU settings - RMA it ASAP.
2. CPB and c-state boost reboots, that occur with PBO tuned - might be fw bugs or, as previously mentioned, mb voltage supply issues. Usually happen when idle.
3. Reboots under load are the result of messed OC or tuning.
Sorry, don't get the meaning of this comment.reboots under load can also be the result of messed up oc, especially cache memory hierarchy.
I believe on my Asus ROG Strix X470 and B550 motherboards, it was enabled by default.
I'm pretty sure I had to manually go in and disable it.
Sorry, don't get the meaning of this comment.
It can if you also use the curve optimizer to set a negative voltage offset, which would allow for a higher clock at load but potentially result in too low of a voltage at idle or low load situations.As for the reboot at idle, I don't think it has much to do with PBO2 tuning, based on my experience.
It can if you also use the curve optimizer to set a negative voltage offset, which would allow for a higher clock at load but potentially result in too low of a voltage at idle or low load situations.
How low of a voltage would you have to set for that to happen? When I manually set low voltage offsets on my Matisse (3900X) all it would do is downclock like crazy, or "false clock" (read a higher clockspeed but rapidly downclock to retain stability, killing performance).
It can if you also use the curve optimizer to set a negative voltage offset, which would allow for a higher clock at load but potentially result in too low of a voltage at idle or low load situations.
Out of curiosity, are these conclusions purely theoretical or based on your personal experience?PBO/PBO2 are a major cause of reboot at idle on Ryzen chips
It depends on the particular CPU though in general for the 5000 series, the 5900x and lower appear to have quite a bit of headroom while the 5950x is already optimized by AMD (probably to make it shine even more). Here's a video about using it to overclock:How low of a voltage would you have to set for that to happen? When I manually set low voltage offsets on my Matisse (3900X) all it would do is downclock like crazy, or "false clock" (read a higher clockspeed but rapidly downclock to retain stability, killing performance).
Out of curiosity, are these conclusions purely theoretical or based on your personal experience?
Well, if you mean -9 for the best core, then you've got a pretty good sample. My 5600x is not bad at all (to say the least), but it barely handle less than -5 on its best core. 2nd best is -10.I could only get -9 on my 5950x. Even -10 would cause a random restart every few days or weeks when the system was idle.
I've had horrible luck with AM4 ASrock motherboards. They were great when I had their Z87/Z97 motherboards, but both of my Asrock x370's had issues, and so did B450's. Asus B450/X470 don't have VRM's built to handle 12/16 cores but at least they're stable. I'm waiting for some kind of sale on gigabyte/msi b550m motherboard to replace my last asrock b450 motherboard.Well, if you mean -9 for the best core, then you've got a pretty good sample. My 5600x is not bad at all (to say the least), but it barely handle less than -5 on its best core. 2nd best is -10.
Not considering the fact that the 5950x silicon itself is quite different from the rest of the 5000's family.
But back to idle restarts. The first ones have occured to me long before people have heard the term Curve Optimizer, even before 5000 launch.
To be precise, first idle reboots were noticed when first vermeer-ready bioses starts to appear. Me personally have experienced it first with taichi x370 + 3600x, then with b550 extreme + 3600x and finally with a current config, until it was fixed in agesa 1.1.0.0 based bios.
I still have a png with a words "still alive" somewhere in a Pictures folder, which I used to put on the screen when leaving the pc on for a long time (power saving was always off) to let me know, if PC has restarted, when I got back to it
That is basically my experience with a sudden idle reboots. Haven't seen it since then, no matter what I do with cpu settings in bios.
PS: have to agree with a poster above, that a poor mb VRM design might be the culprit in the OP's particular case.
I had 2 Asrock motherboards, x470. Both died a horrible death and I got no resolution from Asrock, so they are on my don't buy or recommend list.I've had horrible luck with AM4 ASrock motherboards. They were great when I had their Z87/Z97 motherboards, but both of my Asrock x370's had issues, and so did B450's. Asus B450/X470 don't have VRM's built to handle 12/16 cores but at least they're stable. I'm waiting for some kind of sale on gigabyte/msi b550m motherboard to replace my last asrock b450 motherboard.
I had a X399 Taichi board go, but all my EPYC are Asrock.I had 2 Asrock motherboards, x470. Both died a horrible death and I got no resolution from Asrock, so they are on my don't buy or recommend list.
Strange. PBO isn't supposed to be enabled by default on any board, not even the enthusiast ones. It certainly wasn't enabled on my X570 Aorus Master.
I currently have all of the PBO stuff set to "Auto". Maybe I should change it to "Disabled" then.
I'd choose msi from these two. Have a cheap b450 at the office PC and tested it with 2600, 3600X, 5600X and currently running 5700G. Nothing to complain, except not so great RAM OC potential. Max I've managed to run stable is 4400CL17, but for its price its far above what was declared by specs.I'm waiting for some kind of sale on gigabyte/msi b550m motherboard to replace my last asrock b450 motherboard.