How to optimize my report ... ?

Hi BI Experts
 
I have a power bi in which i am creating ranking of my grouped data in measure as i want my ranking to be calculated with filters being applied. And then on the based of these ranking I am assigning them some alphabets.
 
When I did it with sample data its running fine but when I loaded data for 3 months its throwing out of space error or just does not load the visuals.
 
How to fix this ?
 
Measures Used :
Total Sales Running (%) =
var _tot_Sales = CALCULATE(SUM(SAP_AllSales[SalesSUM]),ALL(SAP_AllSales))
return
DIVIDE(
CALCULATE(
SUM(SAP_AllSales[SalesSUM]), FILTER(
ALL(SAP_AllSales),SAP_AllSales[SalesSUM] >= MIN(SAP_AllSales[SalesSUM]))
)
, _tot_Sales,0)
 
Rank Sales = SWITCH(TRUE(),
SAP_AllSales[Total Sales Running (%)]>= 0 && SAP_AllSales[Total Sales Running (%)] < 0.50, "H",
SAP_AllSales[Total Sales Running (%)] >= 0.50 && SAP_AllSales[Total Sales Running (%)] < 0.90 , "B",
SAP_AllSales[Total Sales Running (%)] >= 0.90 , "T","NA")
 
This is one set, I have a total of 3 Sets.
 
Thanks in advance.