PHP - MSSQL configurations cause slow performance

I have a problem in my project using PHP and MSSQL. I have the following configurations:

64 GB Ram 16 CPU Intel Xeon SQL Server 16 GB Ram 4 CPU Intel Xeon Web Server

And I have the following code:

SELECT 
    protokol.hekim_tc as hekim_tc,
    iller.il_adi as il_adi,
    SUM(protokol.taniveilacolan)as taniveilacolan,
    SUM(protokol.taniolanilacolmayan) as taniolanilacolmayan,
    SUM(protokol.taniveilacolan+protokol.taniolanilacolmayan) as protokolsayisi,
    SUM(protokol.antibiyotik_yazilan) as antibiyotik_yazilan,
    SUM(protokol.agrikesici_yazilan) as agrikesici_yazilan,
    SUM(protokol.enj_yazilan) as agrikesici_yazilan,
    SUM(protokol.enj_agrikesici_yazilan) as enj_agrikesici_yazilan,
    SUM(protokol.antibiyotik_yazilan) as antibiyotik_yazilan,
    SUM(protokol.enj_antibiyotik_yazilan) as enj_antibiyotik_yazilan,
    kalem_sayisi,
    kutu_sayisi,
    maliyet
FROM rdp_2013_protokol_dagilimi_copy2 AS protokol
LEFT JOIN iller ON iller.il_kodu = protokol.hekim_il
LEFT JOIN (
    SELECT hekim_tc, 
    SUM(kalem_sayisi) as kalem_sayisi, 
    SUM(kutu_sayisi) as kutu_sayisi, 
    SUM(maliyet) as maliyet
    FROM rdp_2013_atc_dagilimi
    GROUP BY hekim_tc
    ) AS atc
ON atc.hekim_tc = protokol.hekim_tc
GROUP BY
    protokol.hekim_tc,
    iller.il_adi,
    kalem_sayisi,
    kutu_sayisi,
    maliyet 

The problem is that the query above lasts only 6 sec. in SQL Server. But when I run the same code in PHP on IIS server, it lasts more than 5 minutes. Which configuration am I supposed to look for and change?