The statistics shown in the web page are showing comparison between different SQL engines and they could be used as a base which database to choose, but they are not defining the time limit for your application and usage of the database. For example, the benchmarks are made with index table with 3 columns, so if you have 4 columns there will be a difference between execution time on your side and the time shown there.
You should also have in mind that if you are using indexed table the time will not rise proportional as the entities inserted in the table - if you are inserting X entities for Y time, then if you insert 2X entities it could(and most probably it will) take more than 2Y time because re-indexing and fragmenting the index. Also I assume you have constraints which will slow the inserts too.
It is not correct to compare writing in SQL database and in binary file, because writing in the file system will be always faster than writing in the structured store.
I suppose that your application could be somehow optimized but I am not able to tell you how and where without looking into the code. If you have the possibility to send us your sample project, I will be happy to look into it and if it is possible to suggest optimizations.
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