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How to Have 16GB RAM on T420s?
How to Have 16GB RAM on T420s?
Hey all!
I need to know what to do if I want to have 16GB of ram on my T420s? What modules do I need at what speeds by what brand? Do I have to use proprietary ram? And finally, do I need a bios update/revision? Thank you for any and all of the help you can give me!
I need to know what to do if I want to have 16GB of ram on my T420s? What modules do I need at what speeds by what brand? Do I have to use proprietary ram? And finally, do I need a bios update/revision? Thank you for any and all of the help you can give me!
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RealBlackStuff
- Admin Emeritus
- Posts: 24726
- Joined: Mon Sep 18, 2006 5:17 am
- Location: Loch Garman, Éire
Re: How to Have 16GB RAM on T420s?
You can have up to 2x8GB=16GB of RAM in there, either DDR3-1333/PC3-10660 or DDR3-1600/PC3-12800 will do.
Get Samsung, Hynix, Elpida, Kingston, Crucial etc. (but NOT any so-called Value-RAM).
Nothing else needed, but make sure the laptop is off and main-battery removed, before you swap them.
Get Samsung, Hynix, Elpida, Kingston, Crucial etc. (but NOT any so-called Value-RAM).
Nothing else needed, but make sure the laptop is off and main-battery removed, before you swap them.
Lovely day for a Guinness! (The Real Black Stuff)
But I actually prefer Murphy's from Cork!
But I actually prefer Murphy's from Cork!
Re: How to Have 16GB RAM on T420s?
Hi, I upgraded my T420s with 16GB RAM, with a kit from Kingston (KVR13S9K2/16). It is in their ValueRam category (but bought it before reading your post). It was properly detected by the laptop and seemed to work fine for a while, but then it started getting random crashes. After some testing with memtest86, I got a lot of failures. I switched back to the old 8GB set I had kept, and no problem. So the Kingston RAM is definitely bad.
I wonder what makes the ValueRAM series from Kingston inferior, knowing that Kingston RAM is otherwise pretty good. Do they use memory chips from inferior manufacturers? Or chips that are not tested as thoroughly?
Anyway, do you think the G.Skill F3-10666CL9D-16GBSQ would work fine? Is G.Skill a good brand?
Thanks!
I wonder what makes the ValueRAM series from Kingston inferior, knowing that Kingston RAM is otherwise pretty good. Do they use memory chips from inferior manufacturers? Or chips that are not tested as thoroughly?
Anyway, do you think the G.Skill F3-10666CL9D-16GBSQ would work fine? Is G.Skill a good brand?
Thanks!
ThinkPad T420s
- FHD IPS Panel b140han01.3
- 16GB RAM
- SSD Samsung 850 Pro 512GB
- Dual boot UEFI: Windows 7 Pro / Arch Linux x64
-
RealBlackStuff
- Admin Emeritus
- Posts: 24726
- Joined: Mon Sep 18, 2006 5:17 am
- Location: Loch Garman, Éire
Re: How to Have 16GB RAM on T420s?
G.Skill uses memory chips from different manufacturers.
They DO test them properly first, so no objections against G.Skill (I have G.Skill RAM in my Desktop).
The ValueRam is only minimally tested, they are 2nd choice leftovers.
They DO test them properly first, so no objections against G.Skill (I have G.Skill RAM in my Desktop).
The ValueRam is only minimally tested, they are 2nd choice leftovers.
Re: How to Have 16GB RAM on T420s?
G Skill is okay. I have bought and used a lot of G Skill and never had a problem.
Geil and PNY are the only name-brand company I have had repeated bad experiences with. PNY seems to be gaining popularity again so maybe they stepped their game up.
Posted from my 420 with 2x 8GB!
Geil and PNY are the only name-brand company I have had repeated bad experiences with. PNY seems to be gaining popularity again so maybe they stepped their game up.
Posted from my 420 with 2x 8GB!
1x R500 (P8600), R61e [T9300], X61 (T7300) - RIP T420 (replaced by HP Z420 workstation)
Re: How to Have 16GB RAM on T420s?
I have Kingston HyperX Impact Black 16 Gt KIT (2 x 8 Gt) 1866 MHz DDR3L-SODIMM CL11 on my T420. This together with modified bios and SSD is a nice combination. However, I don't know if there is similar bios for the s-model that can use the memory with full speed.
600E (P3-850Mhz), 3*T60 (3*T7200), T400 (8600Mhz/8GB/SSD120GB), T420 (4180-CA3 with Samsung 850 mSATA 250GB), T440p (i7-4702MQ with Samsung 870EVO 1TB)
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bit_twiddler
- Junior Member

- Posts: 445
- Joined: Wed May 16, 2012 3:36 pm
- Location: Salinas, CA
Re: How to Have 16GB RAM on T420s?
Pricing for DDR3 ram has dropped to the point where there is really no reason to settle for off-brand parts.
If you search for "Crucial 16GB (2 x 8G) 204-Pin DDR3 SO-DIMM DDR3L 1600 (PC3L 12800) Laptop Memory"
on ebay you'll see a listing from Newegg which is pretty reasonable, at least compared to what it used to cost.
I've been testing a pair of these in various machines (T420, T420s) for about a week and they seem
to be pretty solid.
I've also used Kingston and Patriot in the past, and have never had any problems with them,
but I have had some off-brand parts fail.
If you search for "Crucial 16GB (2 x 8G) 204-Pin DDR3 SO-DIMM DDR3L 1600 (PC3L 12800) Laptop Memory"
on ebay you'll see a listing from Newegg which is pretty reasonable, at least compared to what it used to cost.
I've been testing a pair of these in various machines (T420, T420s) for about a week and they seem
to be pretty solid.
I've also used Kingston and Patriot in the past, and have never had any problems with them,
but I have had some off-brand parts fail.
Daily Drivers: W520 i7-2760QM | W520 i7-2860QM | T420 FHD IPS i7-2640m | W701
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Re: How to Have 16GB RAM on T420s?
Hi again,
I received and tested the G.Skill F3-10666CL9D-16GBSQ and it seems fine. No error with memtest. The RAM sticks have Hynix chips on them.
(For the record, I had tried DDR3L RAM before and it wasn't even recognized at POST, so I don't know if DDR3L is fully supported on the T420s, or if it was just bad luck...)
I received and tested the G.Skill F3-10666CL9D-16GBSQ and it seems fine. No error with memtest. The RAM sticks have Hynix chips on them.
(For the record, I had tried DDR3L RAM before and it wasn't even recognized at POST, so I don't know if DDR3L is fully supported on the T420s, or if it was just bad luck...)
ThinkPad T420s
- FHD IPS Panel b140han01.3
- 16GB RAM
- SSD Samsung 850 Pro 512GB
- Dual boot UEFI: Windows 7 Pro / Arch Linux x64
-
bit_twiddler
- Junior Member

- Posts: 445
- Joined: Wed May 16, 2012 3:36 pm
- Location: Salinas, CA
Re: How to Have 16GB RAM on T420s?
I'm not having a problem with mine, but the T420s BIOS is so buggy that
it would not surprise me. Booting from USB seems to be a real challenge with
these machines.
it would not surprise me. Booting from USB seems to be a real challenge with
these machines.
Daily Drivers: W520 i7-2760QM | W520 i7-2860QM | T420 FHD IPS i7-2640m | W701
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
-
thinkpadcollection
- Senior Member

- Posts: 817
- Joined: Fri Oct 17, 2014 8:13 pm
- Location: kingston, ontario, Canada
Re: How to Have 16GB RAM on T420s?
Tx20 and Tx30 non s and s cannot use DDR3L. Use DDR3 with 2Rx8 (16 chips per module) and brand names/major makers in order to have successful 16GB operation. I'm really tired of people here not aware these notebooks have not went on to newer DDR3L yet till T4x0 series.
Cheers, thinkpadcollection
Cheers, thinkpadcollection
-
bit_twiddler
- Junior Member

- Posts: 445
- Joined: Wed May 16, 2012 3:36 pm
- Location: Salinas, CA
Re: How to Have 16GB RAM on T420s?
Not according to this thread:
http://www.tomshardware.com/answers/id- ... -slot.html
but there are apparently a lot of substandard DDR3 sticks out there.
More here:
http://superuser.com/questions/564175/1 ... -overclock
http://www.tomshardware.com/answers/id- ... -slot.html
but there are apparently a lot of substandard DDR3 sticks out there.
More here:
http://superuser.com/questions/564175/1 ... -overclock
Daily Drivers: W520 i7-2760QM | W520 i7-2860QM | T420 FHD IPS i7-2640m | W701
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Re: How to Have 16GB RAM on T420s?
Both my T420s and T430 work with aCrucial 8GB DDR3L-1600 module, combined with a 4GB DDR3-1600 1.5v module, no problems so far.
T480 · i7-8650U · 32GB RAM · 512GB SSD · FHD · NVIDIA MX150 · Fibocom L830-EB
T420s · i5-2520M · 12GB RAM · 480GB SSD · HD+ · HD3000 · F5521gw
Past: T430, T400, T60, T41, T22, 600X, 390X
T420s · i5-2520M · 12GB RAM · 480GB SSD · HD+ · HD3000 · F5521gw
Past: T430, T400, T60, T41, T22, 600X, 390X
Re: How to Have 16GB RAM on T420s?
Indeed!bit_twiddler wrote:Booting from USB seems to be a real challenge with
these machines.
ThinkPad T420s
- FHD IPS Panel b140han01.3
- 16GB RAM
- SSD Samsung 850 Pro 512GB
- Dual boot UEFI: Windows 7 Pro / Arch Linux x64
-
bit_twiddler
- Junior Member

- Posts: 445
- Joined: Wed May 16, 2012 3:36 pm
- Location: Salinas, CA
Re: How to Have 16GB RAM on T420s?
There is a technique described in this thread:
https://forums.lenovo.com/t5/ThinkPad-T ... 397/page/2
but I haven't had time to try it yet.
https://forums.lenovo.com/t5/ThinkPad-T ... 397/page/2
but I haven't had time to try it yet.
Daily Drivers: W520 i7-2760QM | W520 i7-2860QM | T420 FHD IPS i7-2640m | W701
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Others: W510 | 701C (on its shrine)
Non-TP: Dell m7510
Currently Experimenting With: T420s
Re: How to Have 16GB RAM on T420s?
Crucial seconded. CT8G3S1339M.M16FDD
Re: How to Have 16GB RAM on T420s?
It's the memories which are backwards compatible. For example Kingston HyperX HX318LS11IBK2/16 is a kit of two 1G x 64-bit (8GB) is DDR3L-1866 CL11 SDRAM (Synchronous DRAM) 2Rx8, low voltage, memory modules, based on sixteen 512M x 8-bit DDR3 FBGA components per module. Total kit capacity is 16GB. Each module kit has been tested to run at DDR3L-1866 at a low latency timing of 11-11-11 at 1.35V or 1.5V.thinkpadcollection wrote:Tx20 and Tx30 non s and s cannot use DDR3L. Use DDR3 with 2Rx8 (16 chips per module) and brand names/major makers in order to have successful 16GB operation. I'm really tired of people here not aware these notebooks have not went on to newer DDR3L yet till T4x0 series.
So these run with 1.5V if mb cannot provide lower voltage.
EDIT: As above told I have these and running these with help of modified bios at full speed (1866).
Last edited by RistoE on Sat Aug 27, 2016 6:08 am, edited 1 time in total.
600E (P3-850Mhz), 3*T60 (3*T7200), T400 (8600Mhz/8GB/SSD120GB), T420 (4180-CA3 with Samsung 850 mSATA 250GB), T440p (i7-4702MQ with Samsung 870EVO 1TB)
-
WarMachine
- Junior Member

- Posts: 472
- Joined: Sat Nov 18, 2006 3:38 pm
- Location: Lyon, France
- Contact:
Re: How to Have 16GB RAM on T420s?
Hello,
When I choose RAM for my machines, I try to buy certified modules. I plan to buy Kingston modules for which Kingston certifies the compatibility with the T420s. The reference is KCP313SD8/8 (you can use two of those to have 16 Gb in your Thinkpad).
You'll find plenty of infos on Kingston's site if you search memory modules : http://www.kingston.com/us/memory/search/options
Have a good day !
W.
EDIT : On this type of machine, I prefer to use 1.5V memory modules with 1333 Mhz frequency. It seems that some modules at 1.35V with a frequency of 1600 MHz are compatible. I have a friend who uses some G.Skill F3-1600C11D-8GSL ( http://www.gskill.com/en/product/f3-1600c11d-8gsl ). Everything works fine, according to him.
When I choose RAM for my machines, I try to buy certified modules. I plan to buy Kingston modules for which Kingston certifies the compatibility with the T420s. The reference is KCP313SD8/8 (you can use two of those to have 16 Gb in your Thinkpad).
You'll find plenty of infos on Kingston's site if you search memory modules : http://www.kingston.com/us/memory/search/options
Have a good day !
W.
EDIT : On this type of machine, I prefer to use 1.5V memory modules with 1333 Mhz frequency. It seems that some modules at 1.35V with a frequency of 1600 MHz are compatible. I have a friend who uses some G.Skill F3-1600C11D-8GSL ( http://www.gskill.com/en/product/f3-1600c11d-8gsl ). Everything works fine, according to him.
701Cs|755Cs|560|600E|T23|X20|X24|X31|T30|R30|T41p|T42|T43|X41
T60|T61|R60|X60t|X61s|X61t|X301|T400|T400s|W500|X200|X201|T410|T410s|X220|T420|T420s|W520|T430|T430s|T431s|X240|T440|T440s|T440p|W541|T450|T450s|X250|X1C3|T460|T460s| X260|P50|T470s|P52|T480s|T580|X280|T490|T490s
T60|T61|R60|X60t|X61s|X61t|X301|T400|T400s|W500|X200|X201|T410|T410s|X220|T420|T420s|W520|T430|T430s|T431s|X240|T440|T440s|T440p|W541|T450|T450s|X250|X1C3|T460|T460s| X260|P50|T470s|P52|T480s|T580|X280|T490|T490s
Re: How to Have 16GB RAM on T420s?
someone noted in another thread that using 1.35v (and not 1.5v) sodims in t420 causes overheating - do you agree?RistoE wrote: ↑Tue Aug 23, 2016 1:30 pmI have Kingston HyperX Impact Black 16 Gt KIT (2 x 8 Gt) 1866 MHz DDR3L-SODIMM CL11 on my T420. This together with modified bios and SSD is a nice combination. However, I don't know if there is similar bios for the s-model that can use the memory with full speed.
i have used 12800 1.35v and did not notice anything
What modification did you do to bios for ram to run higher than 1333? is it causing any heating?
T500 - T9600, 8g ram, 1680x1050
T420 - 2450M, 16g ram, 1366x768
X61t - L7500, 4g ram, 1024x768
W520 - 2760QM, 16g ram, 1920x1080
X201 - 560M, 8g ram, 1280x800
T420 - 2450M, 16g ram, 1366x768
X61t - L7500, 4g ram, 1024x768
W520 - 2760QM, 16g ram, 1920x1080
X201 - 560M, 8g ram, 1280x800
Re: How to Have 16GB RAM on T420s?
I do not believe it is possible for the RAM to overheat in that way. There would be laptops on fire all over the world if this was the case. Someone was probably spreading misinformation and it should be disposed of as suppository.
The 1.35v rams support 1.35v as addendum to standard 1.5v. This is intended to market marginal power savings so you buy the T430 that lasts 15 minutes longer in bed on battery than T420.
Use any RAM that fits.
The 1.35v rams support 1.35v as addendum to standard 1.5v. This is intended to market marginal power savings so you buy the T430 that lasts 15 minutes longer in bed on battery than T420.
Use any RAM that fits.
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Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
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axur-delmeria
- Senior ThinkPadder

- Posts: 4413
- Joined: Mon May 28, 2012 5:49 am
- Location: Metro Manila, Philippines
Re: How to Have 16GB RAM on T420s?
Years ago, I read a blog post about an X220 getting occasional BSODs which the owner suspects is due to the DDR3L sticks running at 1.5V (causing them to run hotter than normal). He actually modified his X220's system board to lower the RAM voltage to 1.45V, after which the BSODs stopped occurring. Too bad I can't find it anymore.
Planned Purchase: T480s i5-8350 FHD Touch
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Re: How to Have 16GB RAM on T420s?
Wild if true! But I am not convinced as I am of the understanding that DDR3L is just DDR3 capable of functioning effectively as DDR3L or DDR3.
I am also not surprised if silicone valley figured out a way to sell rejects of DDR3 as DDR3L, by undervolting them to function as DDR3L without the advertised and intended DDR3-compatability. Actually yea this is probably it yea Case Closed.
Id think buying 1.5v RAM is easier than modifying a BIOS but it worked so I have no judgement. Good on that blogger for thinking outside the box. Live and let live.
I am also not surprised if silicone valley figured out a way to sell rejects of DDR3 as DDR3L, by undervolting them to function as DDR3L without the advertised and intended DDR3-compatability. Actually yea this is probably it yea Case Closed.
Id think buying 1.5v RAM is easier than modifying a BIOS but it worked so I have no judgement. Good on that blogger for thinking outside the box. Live and let live.
sent from my iPhone
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Re: How to Have 16GB RAM on T420s?
I have a T520, so don't know if that is different when it comes to RAM. I took a chance based on multiple positive reviews and bought what is no doubt not the best RAM out there
However, I can always return to Amazon after first install and testing.
What is interesting/confusing based on what I read in this thread, is that these say they are both DDR3 and DDR3L and 1.5V or 1.35V.
Timetec 16GB KIT(2x8GB) DDR3 / DDR3L 1333MHz PC3-10600 Non-ECC Unbuffered 1.5V / 1.35V CL9 2Rx8 Dual Rank 204 Pin SODIMM Laptop Notebook PC Computer Memory RAM Module Upgrade(16GB KIT(2x8GB))
What is interesting/confusing based on what I read in this thread, is that these say they are both DDR3 and DDR3L and 1.5V or 1.35V.
Timetec 16GB KIT(2x8GB) DDR3 / DDR3L 1333MHz PC3-10600 Non-ECC Unbuffered 1.5V / 1.35V CL9 2Rx8 Dual Rank 204 Pin SODIMM Laptop Notebook PC Computer Memory RAM Module Upgrade(16GB KIT(2x8GB))
Re: How to Have 16GB RAM on T420s?
Best of luck to you. A basic "Memtest" bootable utility, or even a software based memtest such as "Prime 95", may help to stress test that your RAM is in good working order.
If you encounter problems, dispute resolution includes Amazon customer support, the Seller's customer support*, your Bank**, your payment method***, or buying better brand RAM****...
*if they exist
**if they're not one of those scummy online banks
***Id
****I'll be shaking and praying if there is no scenario where the price of end-user PC RAM is not greater than a filing fee.
If you encounter problems, dispute resolution includes Amazon customer support, the Seller's customer support*, your Bank**, your payment method***, or buying better brand RAM****...
*if they exist
**if they're not one of those scummy online banks
***Id
****I'll be shaking and praying if there is no scenario where the price of end-user PC RAM is not greater than a filing fee.
sent from my iPhone
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Re: How to Have 16GB RAM on T420s?
I think Lenovo Solutions includes a memtest. Windows 11 has it's own memory diagnostic app. https://www.microsoft.com/en-us/surface ... diagnostic. And other stand-alone memtesters.TPFanatic wrote: ↑Sat Dec 28, 2024 2:26 pmBest of luck to you. A basic "Memtest" bootable utility, or even a software based memtest such as "Prime 95", may help to stress test that your RAM is in good working order.
If you encounter problems, dispute resolution includes Amazon customer support, the Seller's customer support*, your Bank**, your payment method***, or buying better brand RAM****...
I don't think I would have any problem if I wanted to return. Can be returned for any reason in first 31 days. Also says: "Guaranteed Lifetime warranty from Purchase Date and Free technical support" At C$27, I am not worried:)
Re: How to Have 16GB RAM on T420s?
Neither the Lenovo Solutions nor the W11 memory diagnostics would run on my T520. I forget the exact reason, but it had something to do with idiagio.sys. Others had had same problem with various Lenovos.freeagent wrote: ↑Sat Dec 28, 2024 3:42 pmI think Lenovo Solutions includes a memtest. Windows 11 has it's own memory diagnostic app. https://www.microsoft.com/en-us/surface ... diagnostic. And other stand-alone memtesters.
I downloaded and made a USB thumb drive to run Memtest86. I first ran this on my original 2x4Gb RAM. Then when the 2x8Gb RAM arrived, I installed it and ran the app again. It boots directs from BIOS, so does not care what operating software is installed. Anyway, it gave my new low cost Timetec a clean bill of health. I will keep the old RAM as backup!
I had wondered if I would need to update BIOS from ver 1.32 to v1.49 on 'new' MB, for the 16Gb to run, but it seems not. I am still a bit gun-shy (after whitelisting removal attempt) about updating the BIOS!
Re: How to Have 16GB RAM on T420s?
well done!
memtest 86 (and its counterpart memtest 86+) are some of the best PC tools for DIY / home. my boot of memtest 86+ also reads CPU temp, it's really handy for basic input and output solutions!
memtest 86 (and its counterpart memtest 86+) are some of the best PC tools for DIY / home. my boot of memtest 86+ also reads CPU temp, it's really handy for basic input and output solutions!
sent from my iPhone
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
Registry Tweak To Enable 2 Finger Scroll On Old Synaptics Touchpads
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