drill through report performance

i have a simple drill through report based on one parameter (indexed) that runs sub-second in SSMS but through SSRS it takes more like 10+ seconds. Occasionally, it seems like first time running, it takes a second or two which is more like what I expect.

When I look at ExecutionLog3 info I see this:

<AdditionalInfo>
  <ProcessingEngine>2</ProcessingEngine>
  <ScalabilityTime>
    <Pagination>0</Pagination>
    <Processing>0</Processing>
  </ScalabilityTime>
  <EstimatedMemoryUsageKB>
    <Pagination>5</Pagination>
    <Processing>12</Processing>
  </EstimatedMemoryUsageKB>
  <DataExtension>
    <SQL>1</SQL>
  </DataExtension>
  <Connections>
    <Connection>
      <ConnectionOpenTime>2</ConnectionOpenTime>
      <DataSets>
        <DataSet>
          <Name>Instruments</Name>
          <RowsRead>8</RowsRead>
          <TotalTimeDataRetrieval>29471</TotalTimeDataRetrieval>
          <ExecuteReaderTime>29471</ExecuteReaderTime>
        </DataSet>
      </DataSets>
    </Connection>
  </Connections>
</AdditionalInfo>

Any ideas how to improve the performance of the drill thru report? The column being filtered based on the parameter is indexed and when running the sql in SSMS it runs subsecond.