Undervolting Dell laptops with Intel CPUs: Picking the right ones on the used market

[misha1350]

Hello! Recently I got myself a retired Dell Precision 3530 with an Intel Core i7-8750H (which is essentially Latitude 5591 with a dGPU) at my company. Thanks to them disabling the BIOS updates in their Windows 10 Enterprise, it was preserved with an old BIOS up until I bought it. I was able to undervolt rather well, and overall I got a great machine for its price - but I made a rookie mistake:

1. I didn't read if BIOS downgrading was possible, or necessary, for undervolting to work;
2. I didn't turn off UEFI Capsule Updates in the Dell BIOS;
3. I let Windows update my drivers automatically.
4. ??????
5. -15-20% performance, quietness and battery life loss in an instant!

I naively thought that Dell was not an empire of evil, unlike Lenovo's ThinkPad division, because I was not only able to downgrade the BIOS on my ThinkPad T480 from the newest ver. 1.51 to 1.26 (the last one before the dreaded microcode update) without issues, but I didn't need to - since the newest ThinkPad T480 BIOS still let me undervolt.

Apparently, Dell blocks BIOS downgrades outright if it has "critical security updates", which, judging by the amount of angry people who reported more heat, noise and outrageous idle power consumption, I assume, is a codeword for "critical planned obsolescence shenanigans". The last BIOS version for Latitude 5591 and Precision 3530 that supports undervolting is 1.10, which came out in September 2019 (before roughly November 2019 when they started locking it down). I am currently at 1.33 and I can only downgrade to 1.30

I decided that I would try my luck at the next trading window and I found an even more fantastic deal for me - a Latitude 5501 with an i7-9850H. I don't need a dGPU because I don't game and hardly ever use NVENC for anything (Intel QSV is great enough), but a fast CPU and better battery life due to no dGPU are much needed. The hardware layout seems worse, though, and the 97Wh batteries are not as easy to find as the Precision 3530's 92Wh was, but the CPU makes it worth buying for the $150 it sells for in my country. They seem to have a BIOS version 1.3.2 dating back to August 2019, and the later BIOS versions only came out later. So since the 9th gen CPUs appear to support undervolting too, is this laptop guaranteed to support undervolting?

 

[unclewebb]

is this laptop guaranteed to support undervolting?

When it comes to laptops and undervolting, I would not guarantee anything. Even if you get lucky and undervolting works, you might run into severe power limit throttling which is another Dell feature. I have seen some Dell laptops with 45W TDP CPUs that are forced to throttle along at 10W or less.

I would not buy an 8th or 9th Gen Dell laptop unless I could immediately return it with no questions asked. Even then I would be hesitant. Too many severe throttling problems can start out of nowhere and many of these problems cannot be fixed. Good luck.

 

[misha1350]

Even if you get lucky and undervolting works, you might run into severe power limit throttling which is another Dell feature. I have seen some Dell laptops with 45W TDP CPUs that are forced to throttle along at 10W or less.

I would not buy an 8th or 9th Gen Dell laptop unless I could immediately return it with no questions asked. Even then I would be hesitant. Too many severe throttling problems can start out of nowhere and many of these problems cannot be fixed. Good luck.

I shall then test the throttling in CPU benchmark and videogames, right? Since I have this laptop with surprisingly good build quality and hardly any heat from the keyboard (which is great for us programmers), I would like to see how well it would handle a sustained workload at 35W (which these CPUs seem to be rated for, especially because they only have one fan with two heatpipes). The VRMs on this model are not connected to the heatsink, so I am pretty interested in how well my Precision 3530 that I got for a low price ($220 for a model with i7-8750H, Quadro P600 4GB 25W (also non-undervoltable, sadly), and 32/512GB) handles the job. I will report on how hard it throttles under load later on.

 

[remixedcat]

Hello! Recently I got myself a retired Dell Precision 3530 with an Intel Core i7-8750H (which is essentially Latitude 5591 with a dGPU) at my company. Thanks to them disabling the BIOS updates in their Windows 10 Enterprise, it was preserved with an old BIOS up until I bought it. I was able to undervolt rather well, and overall I got a great machine for its price - but I made a rookie mistake:

1. I didn't read if BIOS downgrading was possible, or necessary, for undervolting to work;
2. I didn't turn off UEFI Capsule Updates in the Dell BIOS;
3. I let Windows update my drivers automatically.
4. ??????
5. -15-20% performance, quietness and battery life loss in an instant!

I naively thought that Dell was not an empire of evil, unlike Lenovo's ThinkPad division, because I was not only able to downgrade the BIOS on my ThinkPad T480 from the newest ver. 1.51 to 1.26 (the last one before the dreaded microcode update) without issues, but I didn't need to - since the newest ThinkPad T480 BIOS still let me undervolt.

Apparently, Dell blocks BIOS downgrades outright if it has "critical security updates", which, judging by the amount of angry people who reported more heat, noise and outrageous idle power consumption, I assume, is a codeword for "critical planned obsolescence shenanigans". The last BIOS version for Latitude 5591 and Precision 3530 that supports undervolting is 1.10, which came out in September 2019 (before roughly November 2019 when they started locking it down). I am currently at 1.33 and I can only downgrade to 1.30

I decided that I would try my luck at the next trading window and I found an even more fantastic deal for me - a Latitude 5501 with an i7-9850H. I don't need a dGPU because I don't game and hardly ever use NVENC for anything (Intel QSV is great enough), but a fast CPU and better battery life due to no dGPU are much needed. The hardware layout seems worse, though, and the 97Wh batteries are not as easy to find as the Precision 3530's 92Wh was, but the CPU makes it worth buying for the $150 it sells for in my country. They seem to have a BIOS version 1.3.2 dating back to August 2019, and the later BIOS versions only came out later. So since the 9th gen CPUs appear to support undervolting too, is this laptop guaranteed to support undervolting?

I have the precision 3550 and I'll see if it has those options I haven't poked around in the bios much... but it hasn't stuttered with audio production even with compelx tracks and at 99-102C it hasn't throttled much and music production needs extremely lo latency and very good cpu governor settings and I have mine set to performance when I open bitwig studio.

@unclewebb ever thought about making a TS for linux? That would be awesome cuz I don't use windows on most of my systems

 

[unclewebb]

ever thought about making a TS for linux?

I thought about it a long time ago but then I came to my senses. Supporting one freeware project for the last 15 years is enough for me.

 

[remixedcat]

I thought about it a long time ago but then I came to my senses. Supporting one freeware project for the last 15 years is enough for me.

Dern...

 

[Hyderz]

I thought about it a long time ago but then I came to my senses. Supporting one freeware project for the last 15 years is enough for me.

I thank you for your time, effort and support in providing the tech community with an invaluable tool

 

[misha1350]

Dell Precision 3530 throttling testing (is it trash or not):
- CPU limited to 80C (PROCHOT Offset at 20)
- Ultra Performance thermal profile (makes the fan blow harder)
- Honeywell PTM7950
- Laptop lifted up by 1cm

It could maintain 39W on the CPU for 32 minutes in Cinebench R23, with the WASD region getting considerably hot due to the single fan located on the right blowing out the back. I assume it's because of the CPU and the VRMs transfering heat to that region.

With the CPU limited to 25W (though you might need just 20W in games), the entire laptop consumed 75W with the combined CPU+dGPU load (Cinebench + FurMark). The dGPU was reported to consume 20W and the temperature reached 76C.

The Quadro P600 is an interesting little potato. You can't overclock or undervolt it, so 20W is pretty much the most it's going to see.
- Time Spy: 1320pts (1169 for graphics)
- Night Raid: 14700pts (18040 for graphics)
- Superposition 720p low: 9523pts (avg. 71FPS)
- Superposition 1080p medium: 2956pts (avg. 22FPS)
- Superposition 1080p high: 2083pts (avg. 15.58FPS)

It's 21% faster than the stock MX150 (which got 7840pts in Superposition 720p low, which I'll use as a point of reference from now on), but unlike the MX150 it can actually play videogames. MX150 is limited to 70C and my ThinkPad T480 throttles hard (it's almost impossible to completely solve the throttling), whereas the Dell Precision 3530 can run games seemingly for hours because of a 92C limit and because there are simply enough VRMs that don't rely on top-tier thermal pads to cool off, which is a major plus for the forgetful average user that cares not about repasting and maintaining their old laptop, not to mention the ease of maintenance for the Help Desk people. Undervolting the MX150 at the same 1708MHz clock to make it throttle less and increasing the VRAM clock speed by +500MHz nets an 7.5% improvement to 8438pts, but it still throttled on my ThinkPad T480

But the Quadro P600 was not made for gaming. And unlike the frankly useless 2GB MX150, It has the great NVENC, 4GB of VRAM for production workloads (including running Phi-3 Mini Instruct locally on CUDA, because it can fit into 4GB of VRAM), and if you still need eSports gaming in a pinch - running OBS with NVENC at 1080p60 only got me 6% less performance at 9049pts. But all 60Hz gamers on the Precision 3530 should install RTSS to limit the games to 60FPS for less VSync-less stutter, less CPU stutter, a smoother image, and better thermals, and I guess you would be able to stream at 1080p60 too.

So I guess Dell can make good laptops if they try, unless cost an arm and a leg, and when Dell business department doesn't stick wrenches into their wheels, forcing planned obsolescence by removing undervolting and other kinds of tomfoolery (and it appears that they do it all the time now). This is still better than HP with its famously bad VRMs and equally bad customer support.

As for my particular Precision 3530, $230 (with a shot battery) in my country is a great price for what is basically an upgrade over the ThinkPad T480/580 with allegedly equally good reliability. I won't try to drop-test it, though.

 

[remixedcat]

I was googling for undervolt precision 3550 and I stumbled upon this:

So it was intel's doing that blocked undervolting bc "security issues" ie, plundervolt or whatever? we are starting to lose so much due to this. I have a feeling intel is doing this on purpose to get us to keep upgrading cuz each new gen is nuked and gimped more and more. ugh.


if the option is hidden on dell bios how do I get it without the bios mod? If I have a good lower version...

 

[Lew Zealand]

I was googling for undervolt precision 3550 and I stumbled upon this:
View attachment 358523
So it was intel's doing that blocked undervolting bc "security issues" ie, plundervolt or whatever? we are starting to lose so much due to this. I have a feeling intel is doing this on purpose to get us to keep upgrading cuz each new gen is nuked and gimped more and more. ugh.


if the option is hidden on dell bios how do I get it without the bios mod? If I have a good lower version...

I'm under the impression that Plundervolt is the reason that post-late-2019 all Dell BIOSes removed the capability to undervolt. It seems that Intel NUCs are also subject to the same restrictions, no surprise there. I have a couple of older Skylake and Kaby Lake Latitudes which did not get the UV-blocked BIOS but all the Coffee Lake Latitude 7490s I have are blocked from UV as I remember our org pushing out BIOSes afterwards for security reasons. I'll probably try to flash back one of the earlier BIOSes but based on posts here, I don't hold out much hope. Not like it matters much anyway as all these Latitudes are limited to about 17W for long-term use.

 

[remixedcat]

I'm under the impression that Plundervolt is the reason that post-late-2019 all Dell BIOSes removed the capability to undervolt. It seems that Intel NUCs are also subject to the same restrictions, no surprise there. I have a couple of older Skylake and Kaby Lake Latitudes which did not get the UV-blocked BIOS but all the Coffee Lake Latitude 7490s I have are blocked from UV as I remember our org pushing out BIOSes afterwards for security reasons. I'll probably try to flash back one of the earlier BIOSes but based on posts here, I don't hold out much hope. Not like it matters much anyway as all these Latitudes are limited to about 17W for long-term use.

I also have a coffee lake wiskey lake latitude (5400/i5 8365u) as well and I updated the bios recently to see about fixing the erratic touchpad and a couple other things bleh!

wonder if the i5-10310u for the precision 3550 would even matter w undervolt at this point??

 

[misha1350]

I have a feeling intel is doing this on purpose to get us to keep upgrading cuz each new gen is nuked and gimped more and more.

Absolutely is the case. I suspected this ever since Intel has released 8th and 9th gen processors, which had double the core count than they used to, making the old processors very power efficient with undervolting applied.

To release a mitigation for a vulnerability that affects literally NO average laptop user, and not making it opt-out, is a nefarious planned obsolescence practice throughout. Lenovo let their users roll back the BIOS and then seemingly added undervolting back in with newer BIOS updates (which is how I was able to undervolt my ThinkPad T480 on the newest 2024 BIOS, as I said before), whereas Dell (and I assume HP too) completely restricted BIOS downgrades, thus forcing people to abandon perfectly good laptops faster because they were getting hotter and the performance was lacking. And then seemingly locking that away behind an HX series paywall, like how AMD did with Cezanne processors and later, is a dead giveaway. At least AMD let all Ryzen 4000 series users undervolt their APUs, making an already very efficient architecture even more efficient and performant during all-core workloads. But Intel and their loyal OEMs did not, it's clear that they smelled danger with Ryzen 3000 in 2019 and wanted to plant these seeds to increase their revenue in the long run by making the CPUs spoil faster, and churning out radical new architectures with good IPC improvements to boost that.

I wonder how it turned out for them, and why it is that they want everyone to undervolt their new 13th and 14th gen CPUs all of a sudden...

wonder if the i5-10310u for the precision 3550 would even matter w undervolt at this point??

It would, if it had undervolting. 10th gen came out after Plundervolt, so only 4th-9th gen mobile CPUs are undervoltable.
Also, a U-series processor in a 15" Precision laptop? Lol.
I'm going to look for a virgin Dell Latitude 5501 with a Core i7-9850H and an old BIOS to switch to, in case I ever find one for cheap. Though it's unlikely that I will, sourcing a new battery for it will be hard (surprisingly harder than for Latitude 5591/Precision 3530) and I don't have disposable income for now. Not to mention that I like my Precision 3530 better despite the gimped CPU performance, because I have a feeling I might need the Quadro P600 later on for a personal project

 

[remixedcat]

Absolutely is the case. I suspected this ever since Intel has released 8th and 9th gen processors, which had double the core count than they used to, making the old processors very power efficient with undervolting applied.

To release a mitigation for a vulnerability that affects literally NO average laptop user, and not making it opt-out, is a nefarious planned obsolescence practice throughout. Lenovo let their users roll back the BIOS and then seemingly added undervolting back in with newer BIOS updates (which is how I was able to undervolt my ThinkPad T480 on the newest 2024 BIOS, as I said before), whereas Dell (and I assume HP too) completely restricted BIOS downgrades, thus forcing people to abandon perfectly good laptops faster because they were getting hotter and the performance was lacking. And then seemingly locking that away behind an HX series paywall, like how AMD did with Cezanne processors and later, is a dead giveaway. At least AMD let all Ryzen 4000 series users undervolt their APUs, making an already very efficient architecture even more efficient and performant during all-core workloads. But Intel and their loyal OEMs did not, it's clear that they smelled danger with Ryzen 3000 in 2019 and wanted to plant these seeds to increase their revenue in the long run by making the CPUs spoil faster, and churning out radical new architectures with good IPC improvements to boost that.

I wonder how it turned out for them, and why it is that they want everyone to undervolt their new 13th and 14th gen CPUs all of a sudden...


It would, if it had undervolting. 10th gen came out after Plundervolt, so only 4th-9th gen mobile CPUs are undervoltable.
Also, a U-series processor in a 15" Precision laptop? Lol.
I'm going to look for a virgin Dell Latitude 5501 with a Core i7-9850H and an old BIOS to switch to, in case I ever find one for cheap. Though it's unlikely that I will, sourcing a new battery for it will be hard (surprisingly harder than for Latitude 5591/Precision 3530) and I don't have disposable income for now. Not to mention that I like my Precision 3530 better despite the gimped CPU performance, because I have a feeling I might need the Quadro P600 later on for a personal project

there's not much good laptop brands out there these days that isn't cooked in some way it seems. gotta pick your poison...

1) dell has awesome and perfect linux support and good repairabillity and parts acquisition, but doesn't put ryzen on biz machines and has restrictive bios and undervolting
2) hp has crap build quality even in biz class and you gotta baby even the biz class laptops from them but they put ryzen in the biz class. they have the most locked down bios I've ever seen as well they take insyde h20 and delete like 70% of the options in it and they force you to get a subscription for drivers and updates behind greenlake subscription for biz grade machines
3) lenovo current linux support isn't the best and they used to be defacto linux laptops and lenovo is taking more of the linux preinstalls away so that's not a good sign for ongoing linux support, they also have half soldered ram on their ryzen thinkpads at the time I looked and if the soldered half fails you gotta get a new mobo or find a way to replace the soldered ram. in order to get full so-dimm you gotta pay 1200 bucks or more also the other kinda security risks w their bios and efi level malware and vulns and such.
4) asus has utter shit customer service, terrible linux support, but has ryzens but is only consumer class so more corner cutting and lately bad build quality
5) acer is flimsy and fragile and hostile to linux
6) framework is awesome all around but expensive and takes a long time to get and who knows how long they will stay in biz I hope a long time. ppl hold on to their frameworks so it's hard to get used ones
7) system 76, same issues w cost as framework and expensive. build quality is ok
8) falcon,meta pcs, cyberpower, etc are all dodgy w linux support and a minefield.

 

[misha1350]

there's not much good laptop brands out there these days that isn't cooked in some way it seems. gotta pick your poison...

1) dell has awesome and perfect linux support and good repairabillity and parts acquisition, but doesn't put ryzen on biz machines and has restrictive bios and undervolting
2) hp has crap build quality even in biz class and you gotta baby even the biz class laptops from them but they put ryzen in the biz class. they have the most locked down bios I've ever seen as well they take insyde h20 and delete like 70% of the options in it and they force you to get a subscription for drivers and updates behind greenlake subscription for biz grade machines
3) lenovo current linux support isn't the best and they used to be defacto linux laptops and lenovo is taking more of the linux preinstalls away so that's not a good sign for ongoing linux support, they also have half soldered ram on their ryzen thinkpads at the time I looked and if the soldered half fails you gotta get a new mobo or find a way to replace the soldered ram. in order to get full so-dimm you gotta pay 1200 bucks or more also the other kinda security risks w their bios and efi level malware and vulns and such.
4) asus has utter shit customer service, terrible linux support, but has ryzens but is only consumer class so more corner cutting and lately bad build quality
5) acer is flimsy and fragile and hostile to linux
6) framework is awesome all around but expensive and takes a long time to get and who knows how long they will stay in biz I hope a long time. ppl hold on to their frameworks so it's hard to get used ones
7) system 76, same issues w cost as framework and expensive. build quality is ok
8) falcon,meta pcs, cyberpower, etc are all dodgy w linux support and a minefield.

Gotta add some more:
3) Lenovo's budget side has some extremely bad design choices, more notably I almost destroyed a gaming IdeaPad L340 because the copper heatsink was not designed with the resistors in mind, so they came into contact after I installed my high performance squishy thermal pads and short circuit sparks. I guess it was designed so badly that not even any components died after that, even though they should have
4) Asus consistently has the most horrible coil whine in the industry with full blown electric crackling, makes you think the laptop will explode any second
6) Frameworks' availability around the globe is lacking
7) No one cares about System76
8) Chinese laptops like HMTEN have dodgy reliability (sometimes really feels like a lottery) and weird BIOS issues, but so does everyone else nowadays
9) Redmi exclusively has soldered RAM, but at least the amount is decent with the 2024 models, not that it matters since the owners hold on to them too as they are Macbook replacements and may only sell them when the 16GB RAM models fall victim to planned obsolescence. Otherwise those are good laptops with mediocre Linux support, providing a good bang for the buck (but people should still buy used ThinkPads and Dell Latitude/Precisions)
10) Honor/Huawei laptops are literally the worst, with the worst examples of planned obsolescence and nefarious design choices, and a huge price to boot. They are only big in Russia for some reason, only the most clueless buyers get them if they don't know must stay away from legacy retail stores and not fall for the marketing that is set up there, and if they have zero idea of what it is they are buying their laptop for

 

[remixedcat]

I could have gotten a cheap thinkbook w ryzen but they have half our fully soldered ram and they are even more flimsy then inspirons and even worse hinge issues.

I chose the inspiron 3525 w ryzen due to it being thin and lite but great thermals for being almost exclusively a couch computer. For on the go and around the house and for trips I got a precision 3550 and latitude 5400 for that. Hubby has an older latitude 6430 that's a beast. Upgradeable cpu and I think gpu too!


Then I allready have a Lenovo w530 and y50-70 and t430. But the t430 needs work on it after a coffee spill and the w530 needs repasted and fan fixed.

 

[misha1350]

I sold off my Dell Precision 3530 to buy another Dell Precision 3530 from an auction with an old BIOS (and make some money from re-selling). I was shocked to find how well it undervolts, or rather, how garbage Intel's Coffee Lake really is.

I made a post on Plebbit to share my findings in detail, but this graph I made should tell you everything you need to know. I am a firm believer that Intel and its partner OEMs like Dell and HP (excluding Lenovo, which kept both undervolting and the ability to downgrade the BIOS) disabled undervolting purely for planned obsolescence reasons, since without undervolting the old Coffee Lake turns into a pumpkin when running on battery. My Dell Precision 3530 would doubly benefit from this, as I can put a 92Wh battery later down the road to make it run for a whole day like some kind of Macbook Pro 16".

Undervolting saved the laptop from the dumpster for one more year. Is it fair to say that I have upgraded my Core i7-8750H to a Xeon E-2176M or higher? Except for having less L3 cache, of course.

 

[WhenMusicAttacks]

man, setup_var is your friend, Dell laptops can be unlocked unlike HP with simple command line uefi tools

 

[PHVM_BR]

man, setup_var is your friend, Dell laptops can be unlocked unlike HP with simple command line uefi tools

On Dell laptops that originally came with BIOS unlocked for undervolt and later had undervolt blocked by the new BIOS, simply select Factory Defaults within the BIOS and undervolt will become available again.

For laptops that already came from the factory with BIOS with undervolt lock, a simple edit will do the trick.