I'm looking to convert to Flexcel from XLSReadWrite. The application in question writes a lot of spreadsheets, and my initial tests show that Flexcel takes around 3 times as long to do the job, which is not going to make my client happy. There are other things that could be going on here, including a conversion from Delphi 2010 to Delphi XE, so I'm not certain that Flexcel is responsible for the slowdown, but I thought I'd ask here whether there were any known speed issues and work-arounds.


We are not aware of any issues regarding speed, and FlexCel for VCL is heavily optimized to create the fastest possible correct files.  (not all solutions generate correct files, and yes, some ones that only write half the records can be faster). I don't know and I don't like to speak about other solutions, so I own't comment in that one. Do you have any FlexCel code that we could use to test this behavior?

I need to write some test routines that eliminate all of the external variables. I'll get back to you.

I now have a simple test program running for both libraries under Delphi 2010. The good news is that TMS is faster assembling the file in memory. The XLS files produced by TMS are somewhat larger, suggesting that the other library is not writing complete files, but the size difference isn't enough to explain the speed difference if we are only looking at the quantity of data. I'll email with some details.

For the benefit of anyone else having similar issues, Adrian and I tracked this down to a product called DriveClone (version 6). When I removed that from my laptop the performance of FlexCel increased dramatically. The latest version of the product, now called FarStone Total Recovery (version 7) does not cause the same problem.