If your iMac is going to be in a place where it will be hard to access the RAM (maybe you don’t have enough room on your desk to lay the screen down and the stand can get in the way of the door a bit), I usually install the RAM as I unbox it. If I’ve got room to move around, I might start it up with the stock RAM first.
In 99.99% of cases, you don’t need to boot with the OG RAM. On the very rare chance that the RAM you bought is defective or incompatible, you’ll know pretty fast and can swap it out and start troubleshooting.
In 99.99% of cases, you don’t need to boot with the OG RAM. On the very rare chance that the RAM you bought is defective or incompatible, you’ll know pretty fast and can swap it out and start troubleshooting.
The only reason I can think of to do the stock RAM first would be if you want to run baseline benchmarks for some reason. But really, the choice is yours. Do whatever is easier for you.