Updating a graphics card
Pull out a tape measure and see how much room you have—or if you're upgrading from an existing graphics card, just measure that.Most graphics cards are around 10 inches long at most, but some custom models with the triple-fan coolers from Asus, Gigabyte, MSI, Zotac, and others can be up to 12.5 inches long.Some budget PCs from a few years ago might struggle, while others would be fine.One place to start is Futuremark's hardware database, where you can pretty quickly find results for most processors; it's not necessarily an exact science, but anything that has a CPU score below 3000 is due for replacement, below 4000 is questionable, and 5000 and above should be okay.Follow the instructions in Apple's How to Upgrade guide, to update your Mac to the most recent version of Mac OS.
After the updates have been installed, check if there are additional Windows Updates available.
A Software Update is an incremental update of the Mac OS and its applications, Security Updates, device drivers, and firmware updates.
For Blizzard games, it is important to download and install all software updates, as our games are designed for the latest version of the supported system requirements.
For the power supply, you'll need something capable of running whatever new GPU you're planning to buy.
Mostly, that means having enough 8-pin or 6-pin connectors for your graphics card.