Welcome to our peer-to-peer forums, where owners help owners. Need help now? Visit eSupport here.

English Community

ThinkPad NotebooksThinkPad T400 / T500 and newer T series Laptops Knowledge Base

Can I use both the HDD and SSD on a T420?


I have a T420 Full model number: 4180-PR1, and have a 320 GB HDD, but it's nearly full so I am thinking about buying an SSD.


 I wanted to know is it possible to have 1 SSD and keep the existing 320GB HDD and run it alongside each other.v


Yes you can, and there are two ways to do it.


1. Buy a mSATA SSD for the OS and put it in your WWAN slot, keeping your old HD where it is for data.


2. Get a 2.5" SSD for OS, swap your old HD out for it and put the old HD in a Ultrabay caddy and swap out your CD/DVD drive for that. It can be hotswapped if you need to use the CD/DVD drive.


Some community users shared that the HDD can be set to spin down when idle so the machine runs cool and quiet. Another thing users can do is to put a bootable Ubuntu and bootable Acronis on the HDD and take regular backups of the SSD and store the image on the HDD, and also make backups of both to an external drive.


To set the drive to spin down:

Control panel -> (Power options) change when the computer sleeps -> Advanced Settings -> Hard Disk -> turn off disk after...


Was this information helpful?

Yes No


zoltanthegypsy On 2015-04-29, 16:17 PM
AllanLindh On 2018-01-29, 0:40 AM

I have the same question, but unfortunately cannot figure out the response.  My T420 hrdw manual doesn't mention having two drives, as near as I can find.  And I have no idea where the WWAN slot is, and the hrdw manual doesn't mention it either.  Sorry to be so dumb, but with luck you'll 75 years old someday also, and then you'll see how opaque computer manuals seem.

doug-jensen On 2018-02-10, 22:27 PM

The T420 has an mSATA socket on the motherboard; Lenovo offers the T420 with nothing, or an mSATA SSD as the boot drive, or with a WLAN (cell phone) modem. The T420 also has a drive bay for either an HDD or SSD in a caddy. The hardware manual shows that it is easy to replace that drive, the only trick is that the OEM drive has an adhesively attached plastic tab for pulling the drive out, which a replacement drive won't have--but you can buy very inexpensive kits on eBay that have that adhesive tab and the two rubber rails for the replacement drive (or with great care you can pull the replacement drive out without using the tab). The T420 also has an Ultrabay into which you can choose to plug another HDD/SSD or an optical (DVD/Blu-Ray) drive or a battery.


I wanted to have a WLAN cellular modem in the mSATA slot so the main drive bay came with a 160GB SSD which I later upgraded to a 1TB SSD. For the Ultrabay, I have a Second Hard Drive caddy with another 1TB SSD--I sometimes swap that out to use the DVD/Blu-Ray drive (I have only data on the Ultrabay drive). Since you can use the small 6-cell battery, or the 9-cell which sticks out the back about an inch, AND/OR the mongo battery slice which attaches to the bottom of the 420 via the docking connector--so that means you probably would be better off not using the Ultrabay for a battery (which probably explains why they are so hard to find anyway).


(I'm 76 but I've been a PC hobbyist/builder since 1981 using DOS on the 8086 LOL.)



AllanLindh On 2018-02-11, 1:01 AM

Dear Doug

Thanks very much.

I started running Fortran prog, entering via punch cards, on an IBM 360 in about 66-67.

They didn't let us work on those, though -- can't imagine why?

It's funny to think that this little T420 probably has more beans than that old 360,

     which I think filled a whole room.

Take care, and thanks again


TST550 On 2018-06-20, 20:31 PM

My laptop is running short of space and as per my requirement, planning to upgrade storage. Please could you help me decide 


Thinkpad T550


Can I replace my 16 GB M.2 SSD(cache drive) with 128GB M.2 SSD and boot windows from this drive?

 I want to use my existing HDD alongside 128 GB M.2 SSD and do not want to compromise on Wifi connectivity

Your guidance will help me decide if i should purchase a M.2 SSD or SSD replacement against HDD

Below is my machine's config


  • Intel Core i5-5200U Processor (3MB Cache, up to 2.70GHz),
    • 500GB Hard Disk Drive, 7200rpm, 2.5"
    • 16 GB Solid State Drive, Serial ATA3 ,Single
    • Intel 7265 AC/B/G/N Dual Band Wireless + Bluetooth Version 4.0
  • • 15.6" HD (1366x768), With WWAN
  • • 4GB PC3-12800 DDR3L SDRAM 1600MHz SODIMM


Kunder On 2018-09-15, 20:38 PM

If you want to upgrade to SSD:


Get a HDD caddy for your optical drive bay. Buy an external DVD burner.


IF you're running a UEFI BIOS Make SURE "Secure Boot" is disabled.


Use Macrium Reflect to image your system to an external HDD. Make sure you make recovery media with Macrium. Preferrably on a USB stick


Install your old HDD into the caddy, but do not install into machine yet.


Install the SSD.


Boot from USB stick you made earlier, pull the macrium image to the SSD, from your external drive. If, for some reason, this doesn't work, Install a clean Windows, Re-pull image.


Install the HDD into the machine, via the optical drive bay, and re-format with Disk manager.


Make a "Users" folder on the D:\ drive. Make a Temp folder in the "User" folder.


RC "Computer">Properties>Advanced System Settings>Environmental Variables.


In the top pane, edit, TEMP  %\USERPROFILE%\AppData\Local\Temp. Change it to: D:\User\Temp.


Change the TMP path also to D:User\Temp.


In the bottom pane, navigate to the TEMP and TMP lines. Set the path to, D:\User\Temp for both.


Send "Documents" and other personal folders to anywhere on the D:\ drive that you like. Just get them OFF your SSD.


NOTE: If you're a Gamer, you can leave "Documents" , on your C:\ drive.


IF you have 8gb/RAM or more, you do not really need a "Pagefile". Eliminate it. If you DO need one, send it to your D:\ drive.


Make sure the firmware is installed, and up to date for your SSD. Make sure "Trim" is available.


Windows 10 is pretty rough on a SSD due to the way updates are done.


To shut off Win10Home Updates, and take control of the Update process yourself:


Here's how:

FIRST, make sure you don't have any updates in the queue, and disconnect from your WiFi.

1) GoTo "Services" by clicking start, and typing "Services".

2) Turn off, and disable Background Intelligent Transfer Service.

3) Turn off, and disable Windows Update.


Click on start, type REGEDIT. Right click on REGEDIT, and choose "Run as Administrator".

1) Navigate to the following key:


2) Right-click on the Windows key, click New, then click Key

3) Enter the name as WindowsUpdate with no space between Windows and Update. You can click and rename it if you make a mistake.

4) Right-click on your new WindowsUpdate key, click New, click Key, and then set its name as AU (in caps!).

5) Click on the AU key. On the right-side, right-click the empty space, click New, click DWORD Value, and name it NoAutoUpdate (no spaces).

6) In the right pane, Double click on your new DWORD, NoAutoUpdate

7) Set the value data to 1. This will completely disable windows ability to update.

If you want to re-enable updates, change it to 0, then re-enable the two services you disabled earlier.


You will no longer be bothered by Windows 10 updates.


You can also save the two registry changes as .reg files.


To turn off updates, shut off the two services previously mentioned, then:

(cut and paste the next three lines to a note pad file and name it , NoUpdates.reg)


Windows Registry Editor Version 5.00




To turn updates back on, re-enable the services, then:

(cut and paste the next three lines to a note pad file and name it , AllowUpdates.reg)


Windows Registry Editor Version 5.00




I've tested this, and it WORKS.


I hope this helps.... Good Luck.



Kunder On 2018-09-16, 16:06 PM



You can use a good, quality SDcard, to route TEMP files, and Personal files to. You just can't run your pagefile from it.

You must eliminate the pagefile, and leave the SDcard in the machine at all times.


This is really helpful on computers that have only a 32, or 64gb eMMCdrive, like the HPstream 14, or any other similar machine.


Some of these machines can be upgraded to 8gb/RAM. If your machine can be upgraded, I HIGHLY recommend doing so. Otherwise, Windows wants to make a pagefile.

Community Guidelines

Please review our Guidelines before posting.

Learn More

Check out current deals!

Go Shop