Officially, the maximum memory in the Dell Latitude E6420 laptop is 8 GB. That is the maximum stated Dell’s website, and the large memory vendors state the same thing. It’s hard for them to guarantee compatibility when the OEM states the maximum is 8 GB. Unofficially, numerous people, including yours truly, have upgraded them to 16 GB. Here’s how to install 16 GB in a Dell Latitude E6420 successfully.
Upgrade the BIOS
The first step is to install the newest BIOS in the system. Dell last released a BIOS update for the E6420, version A25, in 2018. Earlier BIOS versions don’t work with 8 GB. I’ve heard of it working with versions as early as A21, but to be safe, get the last one. Here’s the link to download the A25 BIOS. I’m not generally one for updating a BIOS just for the sake of updating, but in this case it’s a necessary step. Plus, version A25 included some security updates.
Anytime you upgrade a BIOS in a laptop, make sure the battery has a charge and it is connected to AC power. That way, if the power flickers, you have battery backup. By the same token, you aren’t in any danger of running out of battery power with AC also available. Losing power while updating the BIOS’ EEPROM can result in an unbootable system.
Installing 16GB DDR3 memory
After you upgrade your BIOS, shut down the computer, unplug it and turn it over. Remove the four screws holding the 2.5″ drive and the five screws along the edge. The lower cover lifts off, giving you access to the memory sockets. Remove the factory installed SODIMMs and install a pair of 8 GB DDR3 SODIMMs. I used DDR3L-1600, for what it’s worth.
It may have just been the machine I upgraded, but I found the SODIMM sockets were a bit finicky. Be sure to snap both modules fully into their sockets. Replace the cover, then replace the battery and power it on.
When I booted, it only recognized one of the modules. I shut the system back down, reseated both modules more carefully the second time, then put the system back together. This time it told me the amount of system memory had changed, and when I ran the configuration utility, it indeed saw 16 GB. I exited the utility, booted into Windows, and Windows recognized all 16 GB.
The second generation i3/i5/i7 processors in these machines are getting a bit old, but they remain surprisingly capable when you pair them up with 16 GB of RAM and an SSD. We tend to overestimate what percentage of our computing needs are CPU bound versus how many of them are memory and disk bound. Dell doesn’t support Windows 10 on them, and Microsoft won’t support Windows 11 on them and Windows 10 goes end of life in October 2025, but upgrading the memory makes the machines more useful as Windows machines in the meantime, and switching them to Linux is always an option. A second generation i3/i5/i7 with 16 GB of RAM runs Linux nicely.
It does seem like the RAM and SSD breaths life into older hardware. I extended the life of a Dell Latitude D630 to 12 years by doing such upgrades. Well… similar. I did the SSD HDD hybrid on that one which was quite the speed boost in 2012… I think. Also for the D630, Dell said it could only take up to 4GB of DDR2 RAM but a bios upgrade later and it could take 8 GB. Pretty great for the time!