I had the same problem but noticed that I was using the 32 bit version of notepad++, installed the 64 bits instead and had no problems with large files

Tbf npp has much more functionality than regular notepad.

Just the syntax highlighting alone probably dramatically lowers the amount of text it can render.

I've opened 4GB files with notepad++ before. Sure, it takes several minutes (I basically have to go away and do something else, or leave it loading in the background) but it gets there, eventually.

Just upload it in the cloud and use Microsoft online word!

\s

With bigger files or searching in files where there's a lot of data I found sublimetext to be much more efficient (than n++)

There's a npp plugin called Big Files, I haven't used it but it might be worth a look.

That sounds backwards... I occasionally have to open log files of 1 gig or more, and notepad++ gets sluggish, but is usable, while notepad just hangs until I kill it...

Use Vim.