Your Dell Inspiron 15R 5521 laptop
Your Dell Inspiron 15R 5521 laptop
Most consumer laptops have CPUs permanently attached to the motherboard. Premium and replacement models may feature socketed processors, though no Inspiron falls into those groups. You can replace the entire motherboard with a different Inspiron from the same age and size, swapping in a more powerful CPU, but this isn't cost-effective. Other motherboards won't fit, and standard desktop boards won't either. Focus on upgrading RAM and storage instead. Beyond those options, purchasing a new laptop becomes the better choice.
The chance that another Inspiron board will fit and function with all your specific peripherals is extremely low. The device mainly offers upgrade options for storage and RAM. What are your objectives? If you're aiming for better performance, consider a newer, more capable model.