Code works with one computer only - I need to know what is making it work!

[liiamra]

Dear All,

I have developed an algorithm that manipulates a large number of considerably large Excel files (please refer to the summary at the end).

When I work with few files only, I have no problem with any computer. When I increase the number of files, however, the process doesn't work with all computers. I am particularly interested in knowing what is essential for Excel's performance; is't the # of cores, the clock speed, Excel's version or else?

It works with:
- 2X Xeon QuadCore @ 3.00 GHz (8Cores)
- Windows XP, 3GB Rams
- Excel 2010

It doesn't work with:
- Xeon QuadCore @ 2.40 GHz (4Cores)
- Windows 7, 64GB Rams
- Excel 2013

Summary of the code:
- Merge Excel files up to 800,000 rows per file
- Open Excel files, filter by criteria, and move all rows matching different criteria into different sheets
- Create Master file, merge all newly created sheets and then move each master sheet into a separate workbook
- Create summary files (using index-match, pivot tables, unique values)
- etc...

Thanks in advance for any suggestion,

Regards//
liiamra