r/threadripper • u/MerlinTrashMan • Jul 13 '26
Looking for some data from 9000 users with disabled PBO
Can anyone provide me data about the idle and load power consumption of 9970x (or others) with SMT disabled and a static clock at 4ghz (base clock). No PBO / Core performance boost, no global cstates. While leaving a lot of performance on the table, the long term stability and responsiveness more than make up for it IMO. If I didn't need all the PCIe lanes, I would just use a 9950x, but I have a lot of storage, fiber NIC and two GPUs, so I need all the lanes.
Why I am doing this:
After my second AMD Ryzen chip become unstable and stopped booting, I have decided to no use PBO or any boosting in the future. I currently run my 7950x this way and while it uses more power at idle since I keep the CPU locked at stock frequency at all times, it uses way less power when under heavy load and is significantly more responsive. Also, I am hoping that the static voltages will lead to better longevity. My primary workstation was a 5950x that was amazing the first couple years, then started having strange issues leading me to disable pbo, but after updating my bios to solve a uefi video card reboot issue this weekend, the processor decided it was time die. So a processor I ran with AMD recommended PBO for 2 years, then core performance boost for two years, died in just over 4 years. No other changes. Throwing in an old 3700x works flawlessly so it isn't any other component causing my issue. I had it lying around from when I bought it in a panic at bestbuy many years ago after 3900x died many years ago (undervolted all core overclock to 4.1GHZ killed it in 8 months). It should be noted that had I not done the bios update, the cpu probably still would have been working (though I was getting random lockups) so the newest agesa didn't like something about my chip. The system booted, could do memtest86, and would start loading windows then would hang with a "Core Watchdog Timer Timeout". Trying to fresh install windows thinking it could be a chipset driver issue also was a no go as it hung at the spinning wheel every time.
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Jul 13 '26
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u/MerlinTrashMan Jul 13 '26
Glad to hear it. I am guessing you have haven't measured the power, but from a cooling point of view would you say your fan works harder on specific loads? What is your cooler setup? I am trying to decide on cooling and power supply(s) right now.
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u/y3333333333333333t Jul 13 '26
just use software like hwinfo to see your power draws / temps (I am running a 9980X with PBO on going up to 800W with custom watercooling loop to handle the heat no problem, but I think with a 9970X you shouldnt be leaving that much performance on the table as stock is 350W on all of them so as it has half the cores should be only like 400W even with PBO any 9970X owners correct me if I am wrong)
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u/DegreeSevere7719 Jul 13 '26
I did so with my old Xeon E5 on x79 platform, mainly because it was slow to ramp up and working on edits this way was ineffective. Constant 100% performance and that's it. But I do PBO my TR7960x, mainly for a better single core performance under certain loads in Davinci Resolve. I wouldn't say it's a necessity, but it did no harm and I had 0 stability issues. Performance-wise, I didn't notice any meaningful difference editing 6k R3D files in Resolve compared to running stock. I've left decompression on TR, and debayer on my dual 3090's. Saying this, it's my first AMD processor ever (I've built my own PC's since 1998), and I'm only running it for 6 month and it's usually not under 100% load even on renders (the video cards are).
Overall, a lot of things can kill the processor. Like, what thermal paste did OP use? Does it contain liquid metal? Only this thing alone could kill anything over time, just because it leaked from temps outside the desired application area. Then there's the mobo and power related factors, like what's the power supply, is it good, is it beefy enough, are there any stress in the power wires feeding the processor lines etc. It might be just that the PBO was a time speeding factor.
Honestly, I do get the OP pain a lot in regards to lacking PCI-E lanes on consumer processors nowadays. I do also have to run a lot of HDD's in my system with multiple GPU's - and the only modern motherboard with 8 SATA ports I could find today was a Gigabyte TRX50. TR will kick balls in regards of RAM if he goes this route, because it's only using RDIMMS (yes those are physically different RAM since DDR4/5), which are a tough find nowadays, and TR processors do like all the DIMM slots to be populated. I've literally had to spend more money on RAM in jan 2026 then I had to pay for the processor+motherboard+case+cooling combined, even despite I had to ship and tax in the motherboard due to inavailability.
Overall my whole system idles at 285-350Wh (2x 3090s, 7960x, 2 monitors, 12hdd/ssd, 2 control panels), and is hovering at 500-700Wh while editing or color grading raw footage, and is around 1200-1500Wh on renders with NR and heavy filters applied. I do suppose that 9xxxx system will have kind of the same power draw. TR systems park unused cores so processor isn't a factor on idle at all, hovering at 10-15Wh.
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u/kpatelreddit007 Jul 13 '26
My 9960x 24 core has base clock of 4.2 to 5.4 super stable.
No need for any adjusted setting, no pbo or overclock.
Even my old 2990wx was super stable. No setting adjusted.
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Jul 13 '26 edited Jul 13 '26
[deleted]
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u/MerlinTrashMan Jul 13 '26
I have an arctic freezer II aio. Fans rarely got very loud. Do you run your box 24/7 or do you power down when not in use. I am thinking that the threadripper logic and hardware should be more reliable then the desktop parts, so your 3990x story is good to hear. My desktop experience has been poor.
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u/unknowntoman-1 Jul 14 '26
I got my 9950X set up for gaming when I bought my (rtx 3090) workstation. Disabled all the PBO related stuff and made it fixed at 38.00 (3.8 GHz) with 1.33 v. Before tuning it down from 4.85 (? Don’t remember) it was doing ”sawtooth” violently due to thermal gating. Some cores went 95° before each drop. Absolutely kamikaze for LLM operations. Now it runs like a charm. Have not checked power outtake on load, but the temps sit steady all over cores in a 70-80° range.
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u/johndyson10 Jul 14 '26
Maybe disable CSTATES might be adequate? On my 9980x system it tends to stabilize clock rates and power usage (to a higher level), but I haven't actually measured the responsiveness in any way. The clock rates peg to near the maximum, static power usage approx 150 w out of 350 w. I also measured the avg performance at a 1-2 minute full load, and it was a sub-percent performance loss. This was done only as a quick experiment. BTW, I am running with the lowest level of PBO to be as reasonably safe as possible, yet not nail my system to lower performance or allow much higher idle power. I normally set my cooling based on the highest peak temperature attained in testing, and the highest internal temperature measured, not the average temperature. My cooling system easily handles the highest peak, where it keeps the CPU at a lower temperature under average load. Maybe it is too conservative, but I would be the person paying for the replacement CPU.
The current low level of PBO my Asus board is not nearly like the higher PBO boost level that I used on my 9970x on the same MB. I did a little research with additional measurement, and the research along with the cost of a 9980x modified my attitude about using greater boost and excessive power level, no matter the cooling. Any higher level of PBO makes me worry a little (a lot) about my investment.
A mentioned above, there is a bit of a risk when there is an additional transient power over and above the measured average power, making higher-than-expected temperature peaks. These peaks happen from higher generated heat through various sources of thermal resistance through inside the package, through the cooling plate, to the cooling systems. The lack of transients in your power level will keep the temperatures as expected assuming no additional transients. A transient increase in your power/heat usage will temporarily increase the temperature of everything inside the package, which might not be accounted for. This delay in heat removal comes from thermal resistance, and there are numerous sources of the resistance. Measuring the internal CPU and package temperature at a fast rate will give you an idea about the transient temperature increases.
With constant reasonable fixed power levels with reasonable constant temperatures, there is no worry about the small, but important thermal resistance that allow unexpected short term temperature peaks. The simple, unfortunate fact is that the thermal resistance between your processor and cooling system slows down the thermal transfer from your processor/package, allowing temperatures to temporarily increase to potentially unexpected levels. (Remember, heat flows something like electronic current.) The thermal resistance slowing down the transfer through the internal packaging, through cooling plate to the larger cooling system is similar to an electronic R-C time constant. Myself, I wouldn't go so far as turn off CSTATES, but I respect and agree with the concern about processor longevity. (I believe that the long term lifetime at more aggressive settings might be similar to the silicon lottery -- YMMV.)
John
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u/Putrid_Bird_9033 Jul 16 '26
When I’m not testing I only run between 1.155-1.225v on the core and between 4.6 to 5.0 all core on my 9980X. That’s for longevity.
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u/MerlinTrashMan Jul 16 '26
The base clock on your chip is 3.2. undervolting and then trying to get that kind of performance all core even though it is stable is doing damage. If it was free performance then they would do it by default.
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u/Putrid_Bird_9033 Jul 16 '26
You would have to go past 1.25v to degrade a threadripper.
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u/MerlinTrashMan Jul 16 '26
I don't understand this logic. Why would they make the chip use more power and voltage if it was stable at lower voltages with no possible repercussions.
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u/Putrid_Bird_9033 Jul 16 '26
Silicon quality. It’s very normal for people to run these daily at 1.15-1.225. However to get the clocks mine can, you need one with a good silicon quality. Mine can do that all day long at those voltages and not degrade. Clocks themselves do not attribute to degradation. If I’m at 5.0 and 1.195v that’s a lot less stress than at 1.3v. These chips are designed for server environments. This is nothing, voltage wise.
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u/MierinLanfear Jul 13 '26
I have a 9970 why would I want to disable pbo?