Upgradeable:  memory, hard drive (to SSD or larger capacity drive).  Wireless network adapter.

May be upgradeable but limited:  CPU (if there's an i7 of the same generation that's faster, you may be able to upgrade).  In general -- not worth the effort;  you won't gain much.

Cannot be upgraded:  mainboard, video chip (the video chip is a permanent part of the mainboard, and unlike desktop systems, the mainboard is model-specific so nothing else will fit. There is no video card - the video chip soldered in.

If the system has slowed down appreciably, it may be time for a thorough cleanout of all dust inside the system and a replacement of the thermal pads that sit between the heatsinks and the CPU/GPU heat slugs.

Thanks for the reply. Whats the max memory possible? Also, doesnt nvidia cards come as pluggable type? I thought other than the integrated intel video card. Nvidia shd have been replacable.

The system can take up to 2x8 or 16 G of RAM.

Your system began a transition that is now essentially complete - it was an early adopter of the slim format that forced the elimination of separate video cards.   The GPU is a chip soldered to the system board - now, just about the only systems left with true, separate video cards are the 17" and larger gaming systems (Alienware, Clevo, etc.).  Just about everything else has soldered in video whether "discrete" or "hybrid".

It's just physically impossible to fit a video card into a slim system (and of course once the video chip is obsolete, the system gets replaced rather than upgraded).

is there a way to confirm the RAM max size limit? I remember when I bought the system, the configuration showed max size to be 8GB. 

Thanks for the reply. Does this mean I change one of the RAM slots to add an 8GB RAM from crucial, currently the slots are having 4GB and 2GB installed? I do not think I would need 16 GB in the near future. If this is possible, I would definitely upgrade it replacing my 2GB RAM slot.  

my current memory configuration is 4GB, 2GB. Does it impact performance in any way? 

The answer below of F2 works great for my linux ubuntu also, However if it did not work, make sure you use the FN next to the windows key in the lower right of the key board.

thanks for the awesome answer stated below...

FN F2,

hi,

I am planning to buy Intel   7260NGW Intel® Dual Band Wireless-AC  card next month. I saw this question posted in this community saying  this card is not compatible with Dell XPS L502X. Here is the link  

Is there any hardware limitation that will impact the cards working? 

Also, is this card 7260HMW IEEE 802.11ac Mini PCI Express compatible one?

Hi,

As planned, I bought an 8 GB Crucial RAM. I now have a total of 12 GB RAM. Will be upgrading to 16 GB by next few months. Wanted to see if this makes a difference before jumping to full scale upgrade. I ran few hardware tests to check if the hardware is authentic. I see that the manufacturers name is coming as 859B. Is this a valid name? My other RAM module is from samsung, that is shown in the report too.