From
https://support.office.com/en-us/article/Excel-specifications-and-limits-1672b34d-7043-467e-8e27-269d656771c3 Excel 2007:
Worksheets referred to by a chart 255
Data series in one chart 255
Data points in a data series for 2-D charts 32,000
Data points in a data series for 3-D charts 4,000
Data points for all data series in one chart 256,000
Excel 2010 & Higher:
Worksheets referred to by a chart 255
Data series in one chart 255
Data points in a data series for 2-D charts Limited by available memory
Data points in a data series for 3-D charts Limited by available memory
Data points for all data series in one chart Limited by available memory
32 & 64 bit (I don't think it is likely the 32 bit limitation is ever exceeded):
32-bit environment is subject to 2 gigabytes (GB) of virtual address space, shared by Excel, the workbook, and add-ins that run in the same process. A data model’s share of the address space might run up to 500 – 700 megabytes (MB), but could be less if other data models and add-ins are loaded.
64-bit environment imposes no hard limits on file size. Workbook size is limited only by available memory and system resources.
(BTW - A June update for 32-bit Excel 2016 added support for LAA that lets it access 4-gig in 64-bit and 3-gig in 32 bit Windows. See:
https://support.microsoft.com/en-us/help/3160741/large-address-aware-capability-change-for-excel)
I have been using Excel 2016 (64-bit) for about a year and it is blazingly fast on low-to-mid level hardware (16G RAM, i5, 64-bit). (NB - the 64-bit choice was not for hobby DMM logging - I used to analyze network security logs which were gigs in size which I would sometimes try winnow and pivot - and not always successfully).