GPT editor / Knowledge base problems

Hi all,

I’m newbie with building custom GPTs. Recently I tried to upload 10+ JSONL files to GPT knowledge section. Each file size is around 50MB. Since it’s a JSONL files, the structure is quite trivial and easy readable.

Whenever I write prompts in GPT builder UI - it works really slow but retrieves the information and and gets required results. When I write a prompt in preview mode, it takes ages, gets at least few errors and in best case scenario (which doesn’t happen often) generates the results. Usually it just finalizes with an error.

Is there a way to make a custom GPT work fast? without errors?
Should I try using API instead of open-ai Web APP? Any tips & tricks?

P.S. I’m using GPT4