Question t420 help!!!

Jun 27, 2021
hey so i have a lenovo thinkpad t420 its supper slow bc its on a hdd (im going to upgrade that) anyways it used to have 4gb ram at 1333 but i added a 1600 4gb that i had in another system. however i think i want to upgrade it to 2*8 gb of ram but i want to do it as 1600 not as 1333 ive seen forums about this thing called coreboot that can override the bios and let it handle 1600 but i cant get enough info on how to do it so pls help. ive also seen that if the bios is old engohf it might let 1600 how can i check if the bios is old enough? sry im a noob at bios stuff thanks!