Lenovo ThinkPad T420i - RAM Upgrade Guide
The Lenovo T420i laptop has two memory slots available for RAM upgrades. It can support a maximum of 8GB of memory. The type of RAM used is DDR3 SDRAM, and it comes in the SODIMM format, which is a smaller design suited for laptops. For best performance, the RAM should have a clock speed of 1333MHz, often labeled as PC3-10600.
Lenovo ThinkPad T420i Memory Specifications & Maximum RAM Capacity
| Specification | Value |
|---|---|
| Laptop Model | Lenovo ThinkPad T420i |
| Total memory slots | 2 |
| Maximum RAM | 8GB |
| Memory type | DDR3 SDRAM |
| Form factor | SODIMM (Small Outline Dual Inline Memory Module) |
| Recommended RAM clock speed | 1333MHz (PC3-10600) |
| Voltage | 1.35V - 1.5V |
| Number of pins | 204-pin |
FAQ about Lenovo ThinkPad T420i RAM
How much RAM can I put in a T420i?
Maximum is 8GB total. You've got 2 slots, so that's 2x4GB sticks. Some people claim they've gotten 16GB working but it's not officially supported and can be unstable.
What type of memory does the T420i use?
DDR3 SODIMM - the laptop-sized sticks, not the big desktop ones. Make sure you get DDR3, not DDR3L or DDR4, those won't work.
What speed RAM should I get for the T420i?
1333MHz (PC3-10600) is what's recommended. You can stick faster RAM in there but it'll just run at 1333 anyway, so save your money.
Can I mix different RAM sizes in my T420i?
Yeah you can do like 2GB + 4GB if you want. Works fine but you'll lose dual channel performance. Better to match them if possible - either 2x2GB or 2x4GB.
Do I need to remove the keyboard to upgrade RAM on the T420i?
Nope, there's a door on the bottom. Just pop it off and you'll see both slots right there. Way easier than some other ThinkPads.
Will any DDR3 SODIMM work in my T420i?
Pretty much, as long as it's regular DDR3 1.5V stuff. The low voltage DDR3L might work but it's hit or miss. Stick with standard DDR3 to be safe.