HANA Memory Used Discrepancy

Hello,

I was wondering if anyone knows how to reconcile the reported MEMORY USED on the OVERVIEW tab in the studio with the number reported by Memory Consumption of all row tables and Memory Consumption of all column tables transactions on the SYSTEM INFORMATION tab. The Overview tab reports a significantly higher number. I understand that there is always working memory and that's why one should only use 50% of available memory but the difference between memory consumed by all loaded tables and reported on the overview table is not 2X but 10X.