7GB is a bit an unusual number; are you sharing the memory with something else (peripherals or VMWare)? If the memory modules are not the same make and specification it would not hurt to test your memory. If you want to make sure it’s not a memory issue you can download the Linux base SystemRescueCd ISO at SystemRescueCd. Boot from that CD and run Memtest+ for an hour or two.
7GB is a bit an unusual number; are you sharing the memory with something else (peripherals or VMWare)? If the memory modules are not the same make and specification it would not hurt to test your memory. If you want to make sure it’s not a memory issue you can download the Linux base SystemRescueCd ISO at SystemRescueCd. Boot from that CD and run Memtest+ for an hour or two.