Has anybody done a performance comparison between Excel 2010 and Excel 2013? Especially running VBA code.

I have a huge Excel file that runs a modelling of some sort. Some of it is formulas in cells but mostly its VBA code. Home PC (Excel 2010) runs 3 days worth of data in 294 seconds. Office PC (Excel 2013) runs it in 223 seconds. Bit of an improvement but the problem is that home PC is a $500 machine and office PC is a $5000 PC. Serious spec machine compared to my home PC. I would have thought the improvement would be much more so was wondering if the Excel 2013 perhaps has more overhead or something than the Excel 2010. Both PC's running Windows 7 64bit and the Excel is 64bit on both machines as well.

Anybody have any ideas?