What's faster? Formula's linked to external sheets or copy/paste via VBA?

Hello,

Conceptually, I want to have a workbook that pulls data from another workbook. What is the fastest way to pull data from that workbook to this workbook on a regular basis (say every minute)?

1) Just having a VBA code update the formulas every minute? The formulas themselves will be linked to data in another closed workbook.
2) Using a VBA code that opens in the other worksheet in the background, copies the data to clipboard, pastes it into the current workbook, and then closes that workbook?
3) Is there an even faster way?

The goal is so that the workbook have minimal calculation time, so the user can still do stuff in it and data updates just occur in the background every minute.

Thanks!

Are there more efficient formulas to minimize calc time? I had been using a sumif formula to update a table from a list that I kept adding to and it would freeze up for 5 minutes before the results would come through. Someone here recommended using a pivot table and even though I was adding a step to move the list into a pivot table, the getdata formula populated my preexisting table almost immediately. It was a big efficiency save.

Day to day I have a large file of unit sales plans with information per model per month covering 2 years of history and projecting out 3 years. Those sales plans are automated to react to changing production plans and then the resulting sales plan is linked to anther spreadsheet where the units and $s are multiplied to create my financial forecast.

I have tried direct links, and indirect links. but so far if I have the three linked spreadsheets open (the third for the balance sheet data) I am constantly watching the calculation %s climb slowly with my hands tied. I have an i9 computer and it doesn't seem to help. are there known highly efficient formulas I should be looking to adopt?