Please consider the risks of the following vulnerability before deciding whether or not to undervolt: https://plundervolt.com/
replies(6):
> If you are not using SGX, no actions are required. If you are using SGX, it suffices to apply the microcode update provided by Intel to mitigate Plundervolt.
It's not nothing, but that seems minor to irrelevant to most people.
those can but 10nm CPUs after Plundervolt can't undervolt , it's disabled from UEFI and not only there's no option to reenable it in the UI, the very EFI variable itself is write locked. I have an X1 Gen 4 (Intel 11th gen) and you just can't do it.
However, this is not good as it remove under-powering range too far. I was getting only about 7% less performance but 90W(!) less consumption when set to my 115W before. Also I wonder if we as a OS of options and freedom have to stick to such very high reference for min values without ability to override them through some sys ctrls. Commit was done by amd guy and I wonder if because of maybe this post that I made few months ago(business strategy?)
That last part being the rub.
I have used this to moderate success on a 8th generation mobile Xeon to drop the temps ~7C under load, and get the system idle from 6w to 4w (going lower would have been really hard as at that point the CPU was responsible for very little of what remained).
Undervolting is not the same as downclocking, it is supplying less voltage which has a strangely profound impact with no performance loss. However your system can be much less stable.
But this is how AMD, Intel and Nvidia have been pushing performance improvements to consumers every generation. To quote Darth Sidious: "UNLIMITED POWER!"
Back then, Intel had the best semiconductor process, and they had a wide margin on undervolting the CPU.
Of course, it's possible that the lower limit has always been there for nvidia, but I just didn't know because I went without a dedicated video card for like 4 years.
For AMD aren't the drivers (partially) open source? Can't the change be reverted?
https://www.reddit.com/r/buildapc/comments/14kll95/intel_i5_...
it seams -100mv - -150mv is the maximum (maybe not stable) undervolting.
You can take that back and get a little more juice, at the risk of instability or time.
No automated system is perfect, /shrug
https://brendangreenley.com/undervolting-2020-dell-laptops-l...
Intel's 13/14th gen CPUs draw significantly (~70-100W) more power on boost, which can stress the VRMs in otherwise correct pairings and lead to current/EDP or power limit throttling. Lowering the voltage at certain frequencies can allow the system to sustain higher clocks without performance degradation.
I don't know about undervolting, but ThrottleStop allowed me to run my 230W laptop off a 65W power adapter by downclocking the CPU to 800MHz!
I loved it.
https://www.dell.com/support/manuals/sv-se/precision-15-5520...
In my experience (working in the field at Anjuna), SGX and other Confidential Computing are quietly used on the server-side in enterprises a lot. It's a part of defense-in-depth, often to protect critical secrets and cryptographic keys, or the systems that manage them.
How long did the battery last? Less than 30m I assume.
Anyway, indeed, that laptop was not designed to run off 65W. Mainly because it had a dedicated Nvidia GPU, but also because it had a bunch of other stuff (couple 6W fans, bright 4K panel, etc.).
The battery basically didn't exist from the very day I got the laptop brand new from Best Buy. I'm not sure if it's possible to get good battery life out of a 99Wh battery while pulling 230W. Of course, you could simply increase the battery capacity, but a not-insignificant fraction of laptop buyers want to bring them on planes so that'd be a pretty dumb idea.
They even tried to make it thin and light, which makes me cringe every time. Gamers don't need thin and light, wtf.
That resulted in a -10C average CPU temperature. Massive!
I don't remember last time I heard the fans. Not even with Docker + Jetbrains IDEs.
I wonder why doesn't it come like this by default. It runs faster too because it's no longer frequently thermal throttled.
Stock settings just work, maybe I lost the silicon lottery but too tired to check anymore.
Is your chip completely stable in all workloads? Would it be stable at 90c? when all Dram slots are occupied? When driving all pcie lanes at max?
I bet that you could make any chip unstable with the right tools and knowledge.
Then I ran RAM tests.
Then I ran NVMe stress tests.
Then I ran GPU stress tests (NVIDIA GPU is underclocked).
Then I ran all of these tests together.
Worked butter smooth. Not a crash to this day.
To be fair, -100mV is on the safe side according to the articles I read at the time. Some folks run at -200mV or less. I don't need that kind of tweak.
Because pumping up the voltage also allows them to increase the base clock frequency without causing instability. Consumers learned to compare the frequencies during the CPU wars so that's what they juice for marketing purposes.
Newer Thinkpads are notorious for this. Many of them can operate fanless 99% of the time if they just undervolted them by 100mV like you did. It's the first thing I do with a new laptop after installing a clean OS.
A few years back, I bought a Dell laptop that was under their "workstation" line. Dell Precision 7520. The default config when ordering these was had a power-hungry nVidia GPU on a dedicated card. I customized the laptop upon ordering to remove the GPU since I wasn't going to be doing anything that needed a GPU. (I just wanted lots of ports, a nice keyboard, and a touchpad with three buttons. Thinkpad was not an option at the time for reasons.)
Unfortunately, the 7520 firmware was hardcoded with power requirements for a fully-loaded system. It came with a big 180-watt brick. I knew that the laptop wasn't going to need that much power, so I would occasionally use a 90W Dell power brick that I had laying around. I turned off the boot-time warning about an undersized power brick, reasoning that if the battery started draining while plugged in, then I would give up and switch to the bigger brick. The battery never drained.
What did happen, though, is that sometimes I would notice that certain UI things were really, really slow. I always ran a lightweight Linux desktop on the laptop, so generally the web browser was the only thing that would cause any serious CPU or memory usage. For the longest time, I just put up with the occasional slowness on big heavy drunk-with-UX-power websites.
Eventually, I got to wondering what was wrong with this laptop that made it _feel_ so much slower _sometimes_ than any other Linux system I dealt with on a daily basis. One day, after working on the couch for a bit in the morning (on battery), I went back to my desk and plugged into the AC and noticed that Slack got _very_ slow. And so did a few other things. Undock the laptop, and things were fast again. Huh, I thought. That's weird. Nothing in the kernel logs or system journal but when I happened to look at the CPU, I saw it was reporting as an 800 MHz Intel Core i5-7300HQ! Okay, that's not right!
It turns out that Dell hard-coded the firmware to throttle the CPU when a lower-than-expected wattage power brick was used. Even in configurations where that wasn't necessary or made sense. This is silly. I would have much rather had my battery start discharging if the power became an issue, than to silently throttle the CPU. (It's very common to monitor the battery! Not the CPU frequency!) (And no, the firmware warning message that I disabled didn't say that it would underclock the CPU if a lower-spec power brick was used. Just that it might lead to system instability or discharging the battery, or something to that effect.)
Anyway, there is a command you can run in Linux to force the CPU back to full speed. Once I did that, I never had any problems afterward.
My laptop throttles the CPU to 800MHz when it thinks it detects a power brick that doesn't have the correct sense wire. Or, more commonly, when the power brick is not all the way plugged in (even if it is working fine).
the reason your chip didn't come like that is because intel plays it very safe when it comes to stability and their margins for error are likely broader than yours, the stochastic nature of the failures means that the voltage margin between one crash for every 2 hours of stress test and one crash for every day of stress test can be hundreds of milivolts, but they're definitely working on it because pat doesn't want you getting free real estate
I agree though, we're all getting slightly off topic
https://old.reddit.com/r/AcerNitro/comments/qvznen/unlock_un...
been aware of the code this is based on but i hope this also provides a set-and-forget experience like on windows.
The only way to test is, unfortunately, to use it until it crashes.
I used https://github.com/datasone/setup_var.efi to modify the UEFI variables. The README has all the info you'd need. It turns out that both a BIOS and microcode update is required to kill off this feature, and you could just configure the BIOS to not lock it.