Problemas de Rendimiento

Hola compañeros. Tengo muchos problemas de rendimiento en mi servidor
de SqlServer. La máquina ya la hemos ampliado en varias ocasiones y da
igual. Debe ser algo que desconozco y me gustaría que a la vista de la
siguiente tabla alguien me pueda empezar a guiar:

MISCELLANEOUS   0.0     0.0     0.0
LCK_M_SCH_S     0.0     0.0     0.0
LCK_M_SCH_M     0.0     0.0     0.0
LCK_M_S 13.0    31409.0 0.0
LCK_M_U 0.0     0.0     0.0
LCK_M_X 0.0     0.0     0.0
LCK_M_IS        0.0     0.0     0.0
LCK_M_IU        0.0     0.0     0.0
LCK_M_IX        0.0     0.0     0.0
LCK_M_SIU       0.0     0.0     0.0
LCK_M_SIX       0.0     0.0     0.0
LCK_M_UIX       0.0     0.0     0.0
LCK_M_BU        0.0     0.0     0.0
LCK_M_RS_S      0.0     0.0     0.0
LCK_M_RS_U      0.0     0.0     0.0
LCK_M_RIn_NL    0.0     0.0     0.0
LCK_M_RIn_S     0.0     0.0     0.0
LCK_M_RIn_U     0.0     0.0     0.0
LCK_M_RIn_X     0.0     0.0     0.0
LCK_M_RX_S      0.0     0.0     0.0
LCK_M_RX_U      0.0     0.0     0.0
LCK_M_RX_X      0.0     0.0     0.0
SLEEP   14619.0 1676000.0       1585832.0
IO_COMPLETION   13509.0 10141.0 31.0
ASYNC_IO_COMPLETION     0.0     0.0     0.0
RESOURCE_SEMAPHORE      0.0     0.0     0.0
DTC     0.0     0.0     0.0
OLEDB   404.0   1.3300961E+9    1869.0
FAILPOINT       0.0     0.0     0.0
RESOURCE_QUEUE  38620.0 2387045.0       841519.0
ASYNC_DISKPOOL_LOCK     0.0     0.0     0.0
UMS_THREAD      0.0     0.0     0.0
PIPELINE_INDEX_STAT     0.0     0.0     0.0
PIPELINE_LOG    0.0     0.0     0.0
PIPELINE_VLM    0.0     0.0     0.0
WRITELOG        18871.0 40580.0 3638.0
PSS_CHILD       0.0     0.0     0.0
EXCHANGE        0.0     0.0     0.0
XCB     0.0     0.0     0.0
DBTABLE 0.0     0.0     0.0
EC      0.0     0.0     0.0
TEMPOBJ 0.0     0.0     0.0
XACTLOCKINFO    0.0     0.0     0.0
LOGMGR  0.0     0.0     0.0
CMEMTHREAD      113.0   0.0     0.0
CXPACKET        0.0     0.0     0.0
PAGESUPP        0.0     0.0     0.0
SHUTDOWN        0.0     0.0     0.0
WAITFOR 1.0     180000.0        180000.0
CURSOR  0.0     0.0     0.0
EXECSYNC        0.0     0.0     0.0
LATCH_NL        0.0     0.0     0.0
LATCH_KP        0.0     0.0     0.0
LATCH_SH        0.0     0.0     0.0
LATCH_UP        0.0     0.0     0.0
LATCH_EX        4.0     0.0     0.0
LATCH_DT        0.0     0.0     0.0
PAGELATCH_NL    0.0     0.0     0.0
PAGELATCH_KP    0.0     0.0     0.0
PAGELATCH_SH    3020.0  392.0   313.0
PAGELATCH_UP    117.0   0.0     0.0
PAGELATCH_EX    4019.0  95.0    95.0
PAGELATCH_DT    0.0     0.0     0.0
PAGEIOLATCH_NL  0.0     0.0     0.0
PAGEIOLATCH_KP  0.0     0.0     0.0
PAGEIOLATCH_SH  878208.0        832969.0        3356.0
PAGEIOLATCH_UP  27.0    61.0    0.0
PAGEIOLATCH_EX  7041.0  36251.0 61.0
PAGEIOLATCH_DT  0.0     0.0     0.0
TRAN_MARK_NL    0.0     0.0     0.0
TRAN_MARK_KP    0.0     0.0     0.0
TRAN_MARK_SH    0.0     0.0     0.0
TRAN_MARK_UP    0.0     0.0     0.0
TRAN_MARK_EX    0.0     0.0     0.0
TRAN_MARK_DT    0.0     0.0     0.0
NETWORKIO       5017.0  1422.0  0.0
Total   983603.0        1.3352924E+9    2616714.0