T420 Upradability

[bravo3]

Hi guys, been long time away. I was just wondering what is the REAL maximum RAM that the T420 can have installed? I ran SiSoft SANDRA and it says it can handle 32 GB. My chassis model is 42136CH3 that I have currently ordered upgrade CPU to i7-2670QM. Officially Lenovo says only 16 GB. Who is really telling the truth?

[RealBlackStuff]

Both.
The quad CPU can handle 32GB (Sandra) but ONLY IF there were 4 RAM slots for 8GB each.
T420 only has 2 slots, hence the 16GB (Lenovo) limit.
Some of its sister W520 laptops have 4 slots.

[axur-delmeria]

16GB is the maximum (two 8GB RAM sticks). The i7-2670QM supports up to four RAM slots (which is why SiSoft SANDRA reports 32GB maximum), but the T420 only has two.

[bravo3]

Thanks guys. That was all very helpful.

[bravo3]

I have managed to install the procie and an 8 GB stick. And its much faster than before and now the hold out is the ancient Toshiba 300 GB HDD. Apparently my T420 model was a 4236CH3 with just one SODIMM slot and the 4 GB soldered to the board. I was wondering if I could take a step further and stick in a whole 16GB stick? Looks like this is a strange model from the standard T420.

[axur-delmeria]

The T420 never had soldered RAM-- there's another RAM slot under the keyboard (check the T420 Hardware Maintenance Manual, see the HMM link below the site banner on top).

As for the HDD, just replace it with a decent SSD. I'd pick the Crucial MX500, Samsung 860 EVO (the newer 870 EVO appears to be problematic.

[bravo3]

Thanks again. Will check for that second SODDIMM slot. Will go and get a decent SSD. And my T420 would be at the same performance level as my T440p with an i7 quad.

[Bionicman]

Thanks again. Will check for that second SODDIMM slot. Will go and get a decent SSD. And my T420 would be at the same performance level as my T440p with an i7 quad.

It won't perform quite the same, but just removing the HDD you will feel it flies.
I'm wondering what better CPU to put in my T420 than the i5 and if its worth it.

[bravo3]

The i7 2670QM will run with the machine and can handle 16 GB of 2 8GB ram sticks. I have successfully bade farewell to the i5. Just make sure to update the BIOS before the upgrade installations.

[TPFanatic]

I hope your quad behaves well. I tried an i7 2630qm in my T420 and I felt it was running too hot and throttling, so I went back to the i5 2520m (which also runs pretty hot).

[Bionicman]

That's strange, the i5-2520 or 2540 seem to make the T420 one of the coolest laptops I've seen. Most of the time I can't hear the fans. Can the i7-2670QM run reasonably stable ?

[theterminator93]

I have the i7 2640m in my T420 and both X220s. It runs hot and clocks back as required depending on the workload, but it's perfectly stable. The T420 also has the Quadro GPU so there's a little extra heat from that too.

[dr_st]

Incidentally, I ran a long (full-drive) Windows Defender scan on my X220 with i7-2640M last night. It took about 3 hours. The CPU went as high as 96C and stayed there for a long time, never going higher, with TPFanControl in 'BIOS' mode. Setting the fan to 'Manual' 64 (max speed) brought the temps ~10C down.

I don't know if the CPU started throttling already, and maybe that's why the scan took so long. Mind you it is still the original fan and original thermal paste, which is 11+ years long at this point. I imagine it could be significantly improved. But even like this - it's hot, but stable.

[axur-delmeria]

Whether a processor runs hot or not is simply "luck of the draw". Some will run cool, others will run a bit hotter, even if they're the both i5-2520M. Between dual-core i5's and i7's though, the latter will tend to run a bit hotter due to having a larger L2 cache (hence more transistors and thus heat) and generally higher clock speeds. Having socketed CPUs is a boon since one gets to test different CPUs and just get the one that runs the coolest. Soldered CPUs don't have that luxury.

[bravo3]

I have the i7 2640m in my T420 and both X220s. It runs hot and clocks back as required depending on the workload, but it's perfectly stable. The T420 also has the Quadro GPU so there's a little extra heat from that too.

Yeah it does run hot but according to Core Temp (TM) 1.18, my RAM load is at 43% with a 43 tabbed chrome browser, a V380 CCTV software, , messenger desktop app and 1 tabbed edge running currently at an average of 73 degrees Celsius for the quadcore and very stable for the past 52 hours.

[bravo3]

Thanks again. Will check for that second SODDIMM slot. Will go and get a decent SSD. And my T420 would be at the same performance level as my T440p with an i7 quad.

It won't perform quite the same, but just removing the HDD you will feel it flies.
I'm wondering what better CPU to put in my T420 than the i5 and if its worth it.

Well I discovered that the mini PCIe slot beside the bottom RAM slot can accept an mSATA drive. Will not have to get rid of the HDD and just transfer Windows to the SSD. Its unfortunate that this machine cannot be further upgraded to Win11 . Will have to eventually look for a Linux distro that will be to my liking soon.

[dr_st]

Its unfortunate that this machine cannot be further upgraded to Win11

Everything can. It is just a question of cost (amount of tinkering required, compatibility and driver/software support level).

[Bionicman]

It won't perform quite the same, but just removing the HDD you will feel it flies.
I'm wondering what better CPU to put in my T420 than the i5 and if its worth it.

Well I discovered that the mini PCIe slot beside the bottom RAM slot can accept an mSATA drive. Will not have to get rid of the HDD and just transfer Windows to the SSD. Its unfortunate that this machine cannot be further upgraded to Win11 . Will have to eventually look for a Linux distro that will be to my liking soon.

This is the slot which is used for WWAN.

[bravo3]

Well I discovered that the mini PCIe slot beside the bottom RAM slot can accept an mSATA drive. Will not have to get rid of the HDD and just transfer Windows to the SSD. Its unfortunate that this machine cannot be further upgraded to Win11 . Will have to eventually look for a Linux distro that will be to my liking soon.

This is the slot which is used for WWAN.

Yep, and I have no need for it and just happy to have the standard wifi connected to a mobile device

[Alex486sx]

Hi All. I got 8GB RAM on my T420 (2x4GB) and it runs Windows 11 alright, same feel like it was under Windows 10.

[bravo3]

How did you go about it?

[Alex486sx]

Hi All. I got 8GB RAM on my T420 (2x4GB) and it runs Windows 11 alright, same feel like it was under Windows 10.

[ bite... bite... ]

How did you go about it?

I remember that I downloaded Win11 Education ISO, created installation usb drive with Rufus selecting options to remove compatibility checks. Then ran LoveWindowsAgain to remove basic telemetry. After that it just worked, even with 4GB RAM that I had before upgrading to 8GB.

To be honest I don't have much load, but can keep a few things running at the same time on it just fine. Like Chrome with 5-10 tabs + Excel 2016 + PowerPoint 2016 + Postman run well together. Even when a monitor is connected as extended screen.

[bravo3]

How did you go about it?

I remember that I downloaded Win11 Education ISO, created installation usb drive with Rufus selecting options to remove compatibility checks. Then ran LoveWindowsAgain to remove basic telemetry. After that it just worked, even with 4GB RAM that I had before upgrading to 8GB.

To be honest I don't have much load, but can keep a few things running at the same time on it just fine. Like Chrome with 5-10 tabs + Excel 2016 + PowerPoint 2016 + Postman run well together. Even when a monitor is connected as extended screen.

NICE!!

[bravo3]

Then scouring through the internet found a site that says you could upgrade the GPU chipset? Is that true?? Maybe with soldering and tech sleuthing. But i highly doubt it. Haven't gone through the innards of mine to see if that was ever possible.

[theterminator93]

If you have the tools you can flash CoreBoot to the T420 to unlock Ivy Bridge support.

[Alex486sx]

Hi everyone. Do you know if there are Bluetooth drivers for t420 which work under Windows 11? Thanks.

[bravo3]

Hi everyone. Do you know if there are Bluetooth drivers for t420 which work under Windows 11? Thanks.

Isn't that manufacturer specific? You need to find out first what card you may have. You can use Sisoft Sandra to ID the component you need to download the driver for. If not Sandra there are others out there. I am just biased since it gives a complete view of your hardware components.

[Alex486sx]

Hi everyone. Do you know if there are Bluetooth drivers for t420 which work under Windows 11? Thanks.

Isn't that manufacturer specific? You need to find out first what card you may have. You can use Sisoft Sandra to ID the component you need to download the driver for. If not Sandra there are others out there. I am just biased since it gives a complete view of your hardware components.

Good idea, thanks. I just thought that all T420 laptops come with the same bluetooth. Will find out which one I got and will try getting a driver for win11.

[Alex486sx]

Strangely enough Sisoft Sandra didn't detect a bluetooth card in my T420. And all drivers I could find were just for XP and Vista. I tried driver updater program which didn't help either. At the end of the day It's ok without bluetooth, for the backup laptop

[TPFanatic]

For no reason I can tell my primary win 7 install refuses to detect the Bluetooth card in either my T420 or T430.