Installing new RAM memory into macbook pro 2012 13"?

No, you don't have to worry about data. RAM doesn't permanently store data and is emptied whenever you restart. Just turn off your computer, install the RAM according to the instructions, then start your computer. It will automatically recognize and start using the new RAM.

 

Your warranty will remain intact. It will not void your warranty.

 

RAM is a temporary storage for the data your accessing at any one time. Data is transferred from your Hard Drive (or SSD) to RAM for processing by your CPU. Simply restarting your computer will clear those unused processes but you would still be limited to the max amount of RAM in your computer right now. Upgrading and increasing your ram allows more information to be stored during your computer use. If you use lots of programs at once and/or use data heavy programs like photoshop and video editing software, the more ram the better.

 

Not necessarily. To determine if you can benefit from more RAM, launch Activity Monitor and click the System Memory tab at the bottom to check your page outs. Page outs are cumulative since your last restart, so the best way to check is to restart your computer and track page outs under your normal workload (the apps, browser pages and documents you normally would have open). If your page outs are significant (say 1GB or more) under normal use, you may benefit from more RAM. If your page outs are zero or very low during normal use, you probably won't see any performance improvement from adding RAM.

Mac OS X: Reading system memory usage in Activity Monitor

• Apple does not manufacture RAM and charges more than you would pay with other reputable RAM providers.
• Some great sources for Mac-compatible RAM are OWC, Crucial and newegg.com.
• Installation of user-installable parts such as RAM does not void the Apple Warranty or the AppleCare Protection Plan, unless you damage something in the process.
  
  
• MR Guide to Buying RAM
• MR Guide to Understanding Intel Mac RAM
• MR Guide to Matched RAM on Intel Macs
  
  
• MacBook Pro: How to remove or install memory
• MacBook: How to remove or install memory
• iMac: How to remove or install memory
• Mac mini: How to remove or install memory

You can find specs on all Apple products, including maximum RAM:

• By visiting EveryMac.com: Actual Maximum RAM
• By selecting your model on the Crucial Memory Advisor™ Tool to find RAM information
• By using Mactracker
• By entering your serial number here to find specs for your model.
  (Be aware that some models can use more RAM than Apple shows. Check EveryMac to verify actual usable RAM.)

 

You do not seem to understand what RAM is. If you aren't then why are you upgrading it? Save yourself a few dollars and do some research before purchasing anything.

You will need more RAM if you don't have enough. What's not enough? Depending on applications and how many applications is open.