Adding ram

[philster49]

I want add 8 more gb of ram to my Pavilion desktop gaming computer. Do I need to use an ECC stick?

[Venom21]

You need to use a stick with the exact same specs as the preinstalled RAM for best compatibility and performance.  To check current ram details, 

Download CPU-Z, run it, and go to the SPD tab to view details like frequency (e.g., 3200MHz), voltage (e.g., 1.35V), CL timings (e.g., 16-18-18), and XMP or Jedec profile of your existing stick.

Get another 8GB module matching those specs from a reliable brand like Crucial, Kingston, samsung, since you likely have one 8GB stick now, this pairs perfectly for 16GB dual-channel mode (faster than single-channel).

If you later want to replace with more capacity (e.g., 16GB stick), keep voltage, speed, CL rate, and profile identical to avoid issues.
Insert the new stick (check your manual or motherboard labels for the dual-channel pair).