Thinkpad T420 upgrades

2024-06-02

I’ve had a T420 since it came out in 2011. I’ve had fond memories of it, but it’s mostly just sat in the closet collecting dust for years, doing occasional tasks. On a whim I got annoyed by some periodic freezing issues, and while looking it up, found that Thinkpads have a surprisingly vocal following, and a great reputation. They’re even upgradeable! I’m a mega-nerd myself, but never knew this, despite apparently having one of the best thinkpads ever made.

So, I embarked on a series of replacement parts and upgrades that converted a 13-year-old laptop into a surprisingly capable and modern machine. This is a summary of what i did to it (it was fully stock before i began), since not every step of this was particularly clear to me as i began.

Part List Up Top

Total, $172. You can buy a t420 for around $100-$200, if you don’t have one.

Mint 21

For some reason, the root of the periodic freezing issues i had was that I as on Mint 19, on an old kernel. That kernel evidently had some bug with some piece of hardware in the laptop, and a quick reinstall on 21 completely solved it. So just make sure you’re on kernel >5.4.

Storage

The original spinning-platter drives are painfully slow. I had a spare Samsung 850 (from a previous gaming machine, since i use M.2’s now) that i threw into it, which was an immediate benefit. ~550mb/s on the disk benchmark.

However, there’s an mSATA port underneath the machine (the square door with a captured screw, left side). I got interested in this, having never heard of mSATA before. Turns out, it’s the same as SATA, just in a smaller integrated socket, and a predecessor to M.2 itself, which is why it looks similar.

So i grabbed a Kingston SKC600MS 512gb, dropped it in, works great. Benchmarks at 261mb/s, so half the speed of the last-gen gaming SSD, but excellent for integrated mass storage.

Wifi / Firmware

(this step requires Windows, the rest don’t)

The stock wifi chip only supports 2.4ghz, which was the style at the time. I grabbed an Intel AC 7260 dual-band wifi chip, dropped it in, and suddenly failed to boot.

Turns out, the T420 firmware (1.33) has a hardware whitelist for wifi. And all the tools for this require Windows. So, i installed win7 (the license key the laptop comes with is win7 pro oem, so it must be win7 pro) – the iso for which was hard to track down and only found privately. Personally, i installed this on that Kingston drive, so i didn’t have to wipe out the actual Mint installation i meant to use.

First, I had to update to official firmare 1.43, then (via mcdonnell) grabbed a modified bios, and used the included flash.bat to patch the newly-installed bios.

Afterwards, everything booted and seemed to be recognized, but was hard-blocked. Turns out, there’s a wifi hard toggle on the right side of the laptop that i’d accidentally hit.

Expresscard USB 3.0

The laptop came out before USB3 was common, so includes none of those ports. But it does have an expresscard port (which, again, i had never heard of). But, it just had a little spacer that pops out when pressed, and you can just slot any expresscard/34 into it. It’s a little hard to find a use for this, and all the useful products for it seems to just be expresscard to usb3. I grabbed one and dropped it in, works as advertised.

RAM

The t420 supports DDR3 SO-DIMM’s (so, ddr laptop form factor). The stock stick was only 4gb, which is pretty low these days, and usually leads to swapping. I grabbed A-tech 2x8gb, and replacement was fairly easy. The only quirk to note is that one dimm is under the keyboard (right next to the cpu), but the other one is on the bottom, next to the mSATA port. It’s a little strange, but installation was drop-in. Works great.

Battery

The stock battery had given up the ghost long ago, diagnostics show it has 3% capacity remaining, and everything warns that it should be replaced. I’d kept it plugged in for years, since it was basically a dead battery. I grabbed a new one, which had great capacity, fit right in, and with a few deep cycles, works great.

Some comments on this box

These laptops are popular because the keyboard is unbeatable (i still don’t understand why laptop makers don’t all make keyboards like this), the machine is highly durable, and every piece is long-lasting (to emphasize, this machine still worked the same for 13yrs, nothing broke). Plus, much of it is upgradeable and replaceable.

But, the upgrades above probably represent the best that this laptop could be. You’ll likely never get more than 16gb RAM, which will eventually not be enough. The CPU is soldered-in, so while we haven’t really needed new CPU’s for some time, it’ll become more noticeable over the next decade. And, especially, as CPU’s pivot towards price and reduced power consumption, this kind of early-2010’s Intel chip will probably start to look like a ‘68 Mustang – classic, surprisingly good, but not efficient or effective. Same goes for SATA, as we move towards M.2’s for everything, mSATA and SATA will just stay at their 6gb/s limit, which may eventually not be fast enough. etc, etc.

So, while this will undoubtably continue to work for the next 5-10 years, by 2040 I’d expect to not have a legitimate use for this anymore. A 30-year lifespan for a laptop is incredible, and is something of a win for "permacomputing" types such as myself, but on a practical level this isn’t permanent. However, while going through this process, the frame.work laptop caught my eye. Essentially, trying to put together a laptop standard that can allow all major parts to be replaceable/upgradeable, the same way desktops have had for decades. When I need to make my next laptop move, it will probably be that.