Ol' Thinkpad L540 CPU upgrade? (w/w'out fearsome BIOS update) - Page 1
Forum section: electronics / general

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 17, 2019, 08:33:10 pm
content: [TLDR: Thinkpad L540, from i5-4300 to i7-4712, yes/no and how?]Hello Fam,Not sure if this is the right forum here, but it says "computing" and someone is bound to have swapped a CPU before.I have searched the webs but all the Lenovo forums and computer forums assume knowledge I don't have.So, I have an ol' thinkpad L540, which I'd love to keep (because Win7 (yes I'm one of those guys)), and it's been serving me well for te past few years.But, recently, I have begun working with FPGAs, so I'm running Quartus regularly now, which chews up the processor.Every time I hit the compile button, the CPU goes to 11, Quartus doesn't respond for a few minutes and then goes on to compile for another 5;an issue I would wish to address.The bottleneck is most likely the CPU, not only according to the CPU monitor in the task manager, but also because I upgraded everything else I could with my limited skills in this area: I have 16Gb of RAM (all she'll suffer), and I have 4.5Tb of rather fast storage, 500 of which are my Boot sector on an SSD.So, I have procured the largest CPU one could have had in the L540 back when it came out, which according to this doc:https://download.lenovo.com/parts/ThinkPad/l540_fru_bom_20140807.pdfis the i7-4712MQ.Now, I am usually the type of guy to just "pop it in, see what happens", but in this case, I am a bit cautious, because the intel (no pun intended) out there is quite inconclusive, and leave me with several questions I could not find an answer to:1) Do I need to update the BIOS? According to the Linus empire I should (but then again, 3 minute Linus vids...). This is something I am afraid of, as I have managed to roast a motherboard that way before.2) Do CPUs have "drivers"? (is that the word?) Do I need to install a driver? and how does that work?3) Are the two above stupid questions and I literally just could swap, gunk and go?Thanks for all help!

author: Gribo
author_rank: Frequent Contributor
timestamp: December 17, 2019, 09:48:09 pm
content: Are you sure the CPU is on a socket?

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 17, 2019, 09:51:23 pm
content: Yes I am, it is the last Thinkpad to have a socketed CPU.I have checked that, CPU mods have been done before, but the information on how to do so is sparse.

author: Black Phoenix
author_rank: Super Contributor
timestamp: December 18, 2019, 01:29:20 am
content: Quote from: Random Model Maker on December 17, 2019, 08:33:10 pmYou can swap without even needing to update the BIOS. If you choose a CPU that were being sold in a different version of the Laptop you have, chances are (99%) that all the BIOS will support it, including the day one BIOS. Chances are also that the cooling apparatus is also the same, normally they use a normal cooling headsink that cools the hottest CPU the Laptop is sold.There is no drivers, the microcode is integrated in the CPU itself, some updates from Intel update that microcode, sometimes they are windows updates that do that, sometimes is a BIOS update.If it was me I would update the BIOS first (check if the Laptop Battery can hold charge and is at 100% and keep it power on for at least 15min) and then install the new CPU. As told in various videos, DO NOT POWER OFF THE PC DURING THE BIOS UPDATE, EVEN IN THE STATUS BAR ON THE UPDATE LOOKS THAT IS NOT MOVING. If you corrupt the BIOS you will have to desolder it/connect a programmer to program it externally. The BIOS update will do his stuff and turn off/restart the pc by itself.The BIOS update should be less that 5 min, also don't get scared if you see the fans of the Laptop working at 100% when updating the BIOS, since some laptops do that by default.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 18, 2019, 09:04:25 am
content: Thank you, that's finally the clear instructions I have been looking for!Just one more question, if I was to try the swap without updating the BIOS, and my laptop wouldn't boot (or it wouldn't boot for some other reason),would it then work again if I just swapped back? IE I'm not "changing" anything in else the system?Seems like a dumb question again, where the answer should obviously be yes, but better safe than sorry, right?

author: Black Phoenix
author_rank: Super Contributor
timestamp: December 18, 2019, 10:01:05 am
content: Quote from: Random Model Maker on December 18, 2019, 09:04:25 amYes. If everything is correctly connected, if you change the CPU, it doesn't start and you put the old one it will work. Don't forget that you need to change the thermal paste each time.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 18, 2019, 10:04:23 am
content: Sure thing, the more the merrier, right?

author: Black Phoenix
author_rank: Super Contributor
timestamp: December 18, 2019, 11:27:00 am
content: Quote from: Random Model Maker on December 18, 2019, 10:04:23 amNot too much, normally a pea size for the ones with a headspreader on top, a grain of rice for the silicon substrate ones. I prefer to use a grain of rice and then with a old plastic card spread like I'm putting butter on a bread.If all the substrate is covered is OK. Then secure it by tightening the screws in cross pattern, in equal pressures and following the numbers on the plate of the cooler (if they exist).Examples:And to clean it use rubbing alcohol, 95% up or isopropyl alcohol and a piece of paper that doesn't leave fibres behind, I use coffee filter paper.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 18, 2019, 11:30:40 am
content: I was actually thinking about using a Sil pad, I believe they have better thermal conductivity than thermal goo anyway, plus they are less messy

author: Black Phoenix
author_rank: Super Contributor
timestamp: December 18, 2019, 11:43:06 am
content: The ones I know as thermal pads for the CPU are this ones:https://www.amazon.co.uk/Thermal-Grizzly-Carbonaut-Pad-0-2/dp/B07PHN2ZNYI used this ones in some instances and they are very good, you can even cut them to size and reuse them.The normal various thickness Sil pads are saturated fast with the high output of heat that a CPU causes, making like not having anything.But I still prefer thermal paste in this kind of use.

author: LateLesley
author_rank: Frequent Contributor
timestamp: December 18, 2019, 11:49:40 am
content: Just to second Black Phoenix, It should work fine, even without a BIOS update. The the same core family, so should just work with a direct swap.Lenovo tech specs say that laptop can come with up to an Intel® Core™ i7-4600M, and the i7-4712MQ is the same mobile Haswell family of chips.Sources of info -https://www.lenovo.com/gb/en/laptops/thinkpad/l-series/l540/#tab-techspechttp://www.cpu-world.com/CPUs/Core_i7/Intel-Core%20i7-4600M%20Mobile%20processor.html- i7-4600Mhttp://www.cpu-world.com/CPUs/Core_i7/Intel-Core%20i7-4712MQ%20Mobile%20processor.html- i7-4712MQComparison -http://www.cpu-world.com/Compare_CPUs/Intel_CW8064701473804,Intel_CW8064701486506/My only worry was power delivery, but the TDP is the same, so not reall an issue there. Where there might be one, is with your RAM. The old chip supports DDR3 and DDR3L, but the new one only seems to support DDR3L RAM, according to CPU-World's data it may well be wrong. Intels data sheet seems to comfirm only DDR3L, so double check your RAM's spec.

author: Black Phoenix
author_rank: Super Contributor
timestamp: December 18, 2019, 11:56:49 am
content: Quote from: LateLesley on December 18, 2019, 11:49:40 amI made reference to that:Quote from: Black Phoenix on December 18, 2019, 01:29:20 amI just said to update because why not, it always have something extra.DDR3L is a dual voltage capable memory DIMM, which supports operation at both 1.5V and 1.35V. DDR3L is also pin-compatible with DDR3. DDR3 is a single voltage capable memory DIMM, which supports 1.5V operation only. So in this case the RAM will be running at 1.5 volts as your system does not offer a low voltage option. But I don't see Lenovo using 2 types of RAM for the same model, when the CPU is different, it is a recipe for causing problems in assembly. But thanks for that advice, is something that I forgot to check.

author: LateLesley
author_rank: Frequent Contributor
timestamp: December 18, 2019, 01:17:15 pm
content: Yeah, I suspect they used DDR3L so it would scale across all the processors, But my point was, it is worth checking. Its the type of thing that can cause no boot, and if not mentioned, mistaken diagnosis as to why it doesn't boot. It's just the old chip spec was for both DDR3, and DDR3L, and my understanding was that DDR3 was 1.5V minimum, whereas DDR3L was 1.35V minimum. And also the RAM speed could derate at different voltages too. My point was to make people aware that issues could arise there, however slim, since the RAM nowadays interfaces directly with the CPU, rather than through a "Northbridge" like the older days. So changing CPU, you are changing the memory controller, and possibly the compatibility specs too.As for the BIOS thing, I completely agree, apart from its always worth it. Its a risky business for inexperienced folk. One bad flash, and you have a dead board. I've actually got a motherboard to repair, where that exact thing happened, it powered off mid flash. And i'm now chasing adapters and stuff to reflash a new chip. (The old chip since died connecting it up wrong to the USB chip flasher). So I would say, it's mostly worth doing, IF you are confident in the process, and acknowledge the risks. Just for completeness of info.I'm not picking apart your advice, it's all sound. But we have to remember others less experienced can come by, and it's worth them knowing the gotchas.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 18, 2019, 01:37:16 pm
content: Good to know, I believe that I have DDR3L, as the processor is listed in the FRU list, but I'll check on that to be sure. I may also have an i7-4600 in an old machine somewhere, which I could use just in case.I think I'll try without the BIOS update first, as I have the time to do so and thermal goo is cheap anyways.

author: senso
author_rank: Frequent Contributor
timestamp: December 24, 2019, 01:41:59 am
content: How did you "roast" a mobo with a BIOS update?If the BIOS update fails, grab a SOIC clip and flash a BIOS dump and its good as new, you should update the BIOS, more so on a laptop given that there is a lot of firmware that usually gets better with the update..Now, you can upgrade to the CPU you mention, and both CPU's only support DDR3L, so you are covered in that front.Regarding the thermal paste, dont use the cheapest crap known to man, use Artic MX-4, great on laptops, cheap-ish (7-10€ for a 10 gram tube that will be enough for around 100 repastes).Clean your heatsink fins when you take it apart, and all is well.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 24, 2019, 02:02:10 am
content: Quote from: LateLesley on December 18, 2019, 11:49:40 amI have checked, I have two DDR3L-sticks in at the moment, so no worries on that front.Quote from: senso on December 24, 2019, 01:41:59 amTechnically, not with a BIOS-update, but in the following steps. I had bricked the BIOS, so not owning the right probes, but a SOIC-socket, I thought: "just quickly unsolder it", overheated the board and lifted too many traces to be bothered for a repair. It was an old board anyways, which I replaced with a newer, better one, and the headache saved was worth the money.Quote from: senso on December 24, 2019, 01:41:59 amI have plenty of MX-2 around, which always seemed sufficient to me (even for uses outside PC stuff). I guess I could order some MX-4 on occasion, but that would have to wait till after the holidays. We'll see if I can be bothered.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 25, 2019, 07:40:38 pm
content: Quote from: Random Model Maker on December 18, 2019, 10:04:23 amNot really.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: December 26, 2019, 12:59:06 am
content: Quote from: SiliconWizard on December 25, 2019, 07:40:38 pmWhere's the fun in that? The bigger the glob, the better the job, as a smart man once said.

author: LeonR
author_rank: Regular Contributor
timestamp: January 17, 2020, 10:34:34 am
content: Thermal pad (the silicone-y based ones)thermal conductivity is, AFAIK, way lower than a good quality thermal paste, like Arctic MX-4, Gelid GC, etc. Also you aren't supposed to use those on CPUs since the retention mechanism for the heatsink block is made so there's very little space between it and the CPU die.The most error proof solution for applying thermal compound is putting a amount that resembles half of a dry pea (a bit smaller if it's an exposed die) in the middle of the die/IHS, so the pressure exerted by the heatsink spreads it evenly.

author: Random Model Maker
author_rank: Regular Contributor
timestamp: February 05, 2020, 12:01:26 am
content: Just to close this thread for good form:I put the CPU in in my winter holidays, so I have been running for abour a month now.No Bios update was necessary, she just booted like the first day I got her.The stock cooler is way sufficient, I actually hear the fanlessoften now than before. Given my normal usage the processor is floating along most of the time anyways, sice I now have roughly 400% more cores than before.And to close the last parenthesis I did go for Arctic MX-4 in the end (yuck!), two beads of rice left and right, as the die has kind of a 2:1 aspect ratio, that sounded logical to me.The performance seems vastly improved, I still have fluent operation even if multiple intense programs are running simultaneously.Only 3D-CADs like Fusion360 are a bit jerky, but oh well, integrated graphics.....Bloody Intel Quartus is still maxing out every resource though. Well shit (-_-)