essbase scenario more than 24 members slows performance

Im using this query

With

  set [_Account11]  as '{[Account].[TOTOPEXP]}'

  set [_Account17]  as 'Generate([_Account11], Descendants([Account].currentmember, [Account].Generations(17), leaves))'

  set [_CostCentre6]  as '{[CostCentre].[CC10000]}'

  set [_CostCentre13]  as 'Generate([_CostCentre6], Descendants([CostCentre].currentmember, [CostCentre].Generations(13), leaves))'

  set [_Entity_PBF3]  as 'Filter([Entity_PBF].Generations(3).members, (([Entity_PBF].CurrentMember.MEMBER_Name = "SGMTCON" OR [Entity_PBF].CurrentMember.MEMBER_ALIAS = "SGMTCON")))'

  set [_Entity_PBF13]  as 'Generate([_Entity_PBF3], Descendants([Entity_PBF].currentmember, [Entity_PBF].Generations(13), leaves))'

  member [Scenario].[_MSCM1] as 'SUM({PeriodsToDate([Period].[Gen2,Period], [Period].currentmember)}, [Scenario].[Actual])', SOLVE_ORDER = 100

  member [Scenario].[_MSCM2] as 'SUM({PeriodsToDate([Period].[Gen2,Period], [Period].currentmember)}, [Scenario].[Budget])', SOLVE_ORDER = 100