diff --git a/reactos/include/ndk/asm.h b/reactos/include/ndk/asm.h
index 92ed46d6861..fa999b2377b 100644
--- a/reactos/include/ndk/asm.h
+++ b/reactos/include/ndk/asm.h
@@ -109,6 +109,9 @@ Author:
 #define KTHREAD_CALLBACK_STACK                  0x114
 #define KTHREAD_APC_STATE_INDEX                 0x11C
 #define KTHREAD_STACK_BASE                      0x158
+#define KTHREAD_QUANTUM                         0x15D
+#define KTHREAD_KERNEL_TIME                     0x160
+#define KTHREAD_USER_TIME                       0x18C
 
 //
 // KPROCESS Offsets
@@ -145,6 +148,7 @@ Author:
 #define KPCR_SET_MEMBER                         0x48
 #define KPCR_NUMBER                             0x51
 #define KPCR_CURRENT_THREAD                     0x124
+#define KPCR_PRCB_IDLE_THREAD                   0x12C
 #define KPCR_PROCESSOR_NUMBER                   0x130
 #define KPCR_PRCB_SET_MEMBER                    0x134
 #define KPCR_PRCB_CPU_TYPE                      0x138
@@ -152,8 +156,21 @@ Author:
 #define KPCR_DR6                                0x428
 #define KPCR_DR7                                0x42C
 #define KPCR_PRCB_INTERRUPT_COUNT               0x644
+#define KPCR_PRCB_KERNEL_TIME                   0x648
+#define KPCR_PRCB_USER_TIME                     0x64C
+#define KPCR_PRCB_DPC_TIME                      0x650
+#define KPCR_PRCB_DEBUG_DPC_TIME                0x654
+#define KPCR_PRCB_INTERRUPT_TIME                0x658
+#define KPCR_PRCB_ADJUST_DPC_THRESHOLD          0x65C
 #define KPCR_SYSTEM_CALLS                       0x6B8
-#define KPCR_PRCB_DPC_ROUTINE_ACTIVE            0x994
+#define KPCR_PRCB_DPC_QUEUE_DEPTH               0xA4C
+#define KPCR_PRCB_DPC_COUNT                     0xA50
+#define KPCR_PRCB_MAXIMUM_DPC_QUEUE_DEPTH       0xA6C
+#define KPCR_PRCB_DPC_REQUEST_RATE              0xA70
+#define KPCR_PRCB_DPC_INTERRUPT_REQUESTED       0xA78
+#define KPCR_PRCB_DPC_ROUTINE_ACTIVE            0xA7A
+#define KPCR_PRCB_DPC_LAST_COUNT                0xA80
+#define KPCR_PRCB_QUANTUM_END                   0xAA1
 
 //
 // KINTERRUPT Offsets
@@ -432,6 +449,11 @@ Author:
 #define DISPATCH_LEVEL                          0x2
 #define CLOCK2_LEVEL                            0x1C
 #define HIGH_LEVEL                              0x1F
+
+//
+// Quantum Decrements
+//
+#define CLOCK_QUANTUM_DECREMENT                 0x3
 #endif
 
 //
diff --git a/reactos/include/ndk/i386/ketypes.h b/reactos/include/ndk/i386/ketypes.h
index 7fd015215f6..286eb8801da 100644
--- a/reactos/include/ndk/i386/ketypes.h
+++ b/reactos/include/ndk/i386/ketypes.h
@@ -407,7 +407,6 @@ typedef struct _KPRCB
 #endif
     ULONG SpareCounter0;
 #if (NTDDI_VERSION < NTDDI_LONGHORN)
-    ULONG KeContextSwitches;
     ULONG KeDcacheFlushCount;
     ULONG KeExceptionDispatchCount;
     ULONG KeFirstLevelTbFills;
diff --git a/reactos/ntoskrnl/ex/sysinfo.c b/reactos/ntoskrnl/ex/sysinfo.c
index 21d7b968b80..5cced43ab6c 100644
--- a/reactos/ntoskrnl/ex/sysinfo.c
+++ b/reactos/ntoskrnl/ex/sysinfo.c
@@ -1054,7 +1054,7 @@ QSI_DEF(SystemInterruptInformation)
   Prcb = ((PKPCR)KPCR_BASE)->Prcb;
   for (i = 0; i < KeNumberProcessors; i++)
   {
-    sii->ContextSwitches = Prcb->KeContextSwitches;
+    //sii->ContextSwitches = Prcb->KeContextSwitches;
     sii->DpcCount = 0; /* FIXME */
     sii->DpcRate = 0; /* FIXME */
     sii->TimeIncrement = ti;
diff --git a/reactos/ntoskrnl/ke/i386/clock.S b/reactos/ntoskrnl/ke/i386/clock.S
index ee90fd31408..6c7b7afefce 100644
--- a/reactos/ntoskrnl/ke/i386/clock.S
+++ b/reactos/ntoskrnl/ke/i386/clock.S
@@ -20,6 +20,141 @@
 
 /* FUNCTIONS ******************************************************************/
 
+.globl _KeUpdateRunTime2@0
+.func KeUpdateRunTime2@0
+_KeUpdateRunTime2@0:
+
+    /* Get KPCR */
+    mov eax, [fs:KPCR_SELF]
+
+    /* Save EBX */
+    push ebx
+
+    /* Increase interrupt count */
+    inc dword ptr [eax+KPCR_PRCB_INTERRUPT_COUNT]
+
+    /* Get the current thread and process */
+    mov ebx, [eax+KPCR_CURRENT_THREAD]
+    mov ecx, [ebx+KTHREAD_APCSTATE_PROCESS]
+
+    /* Check if this was V86 or user mode */
+    test dword ptr [ebp+KTRAP_FRAME_EFLAGS], EFLAGS_V86_MASK
+    jnz NotKern
+    test byte ptr [ebp+KTRAP_FRAME_CS], MODE_MASK
+    jnz NotKern
+
+    /* Increase kernel time */
+    inc dword ptr [eax+KPCR_PRCB_KERNEL_TIME]
+
+    /* Check if IRQL was DISPATCH_LEVEL */
+    cmp byte ptr [esp+8], DISPATCH_LEVEL
+    jb BelowDispatch
+    ja AboveDispatch
+
+    /* Check if the DPC routine is active */
+    cmp dword ptr[eax+KPCR_PRCB_DPC_ROUTINE_ACTIVE], 0
+    jz BelowDispatch
+
+    /* At dispatch, increase DPC time */
+    inc dword ptr [eax+KPCR_PRCB_DPC_TIME]
+    jmp AfterSet
+
+AboveDispatch:
+    /* Update interrupt time */
+    inc dword ptr [eax+KPCR_PRCB_INTERRUPT_TIME]
+    jmp AfterSet
+
+BelowDispatch:
+    /* Update kernel time */
+    inc dword ptr [ebx+KTHREAD_KERNEL_TIME]
+    jmp AfterSet
+
+NotKern:
+    /* Update user time */
+    inc dword ptr [eax+KPCR_PRCB_USER_TIME]
+    inc dword ptr [ebx+KTHREAD_USER_TIME]
+
+AfterSet:
+    /* Get the DPC Count and last count, and set the ne wone */
+    mov ecx, [eax+KPCR_PRCB_DPC_COUNT]
+    mov edx, [eax+KPCR_PRCB_DPC_LAST_COUNT]
+    mov [eax+KPCR_PRCB_DPC_LAST_COUNT], ecx
+
+    /* Substract counts and add request rate, divide by two to get average */
+    sub ecx, edx
+    add ecx, [eax+KPCR_PRCB_DPC_REQUEST_RATE]
+    shr ecx, 1
+
+    /* Set this as the new request rate */
+    mov [eax+KPCR_PRCB_DPC_REQUEST_RATE], ecx
+
+    /* Check for depth > 0, DPCs to be inactive, and no other pending request */
+    cmp dword ptr [eax+KPCR_PRCB_DPC_QUEUE_DEPTH], 0
+    je DontRequest
+    cmp byte ptr [eax+KPCR_PRCB_DPC_ROUTINE_ACTIVE], 0
+    jnz DontRequest
+    cmp byte ptr [eax+KPCR_PRCB_DPC_INTERRUPT_REQUESTED], 0
+    jnz DontRequest
+
+    /* Request a DPC */
+    mov ecx, DISPATCH_LEVEL
+    call @HalRequestSoftwareInterrupt@4
+
+    /* Restore PCR address */
+    mov eax, [fs:KPCR_SELF]
+
+    /* Get the DPC request rate and threshold adjust, and set it */
+    mov ecx, [eax+KPCR_PRCB_DPC_REQUEST_RATE]
+    mov edx, _KiAdjustDpcThreshold
+    mov [eax+KPCR_PRCB_ADJUST_DPC_THRESHOLD], edx
+
+    /* Check if the rate now is not ideal */
+    cmp ecx, _KiIdealDpcRate
+    jge RateOk
+    cmp dword ptr [eax+KPCR_PRCB_MAXIMUM_DPC_QUEUE_DEPTH], 1
+    je RateOk
+
+    /* Fix the depth */
+    dec dword ptr [eax+KPCR_PRCB_MAXIMUM_DPC_QUEUE_DEPTH]
+    jmp RateOk
+
+DontRequest:
+    /* We didn't request a DPC, decrease the threshold */
+    dec dword ptr [eax+KPCR_PRCB_ADJUST_DPC_THRESHOLD]
+    jnz RateOk
+
+    /* We're at 0 now, reset it */
+    mov ecx, _KiAdjustDpcThreshold
+    mov [eax+KPCR_PRCB_ADJUST_DPC_THRESHOLD], ecx
+
+    /* Get maximum depth and check it */
+    mov ecx, _KiMaximumDpcQueueDepth
+    cmp ecx, [eax+KPCR_PRCB_MAXIMUM_DPC_QUEUE_DEPTH]
+    je RateOk
+
+    /* Increase it, it's below maximum */
+    inc dword ptr [eax+KPCR_PRCB_MAXIMUM_DPC_QUEUE_DEPTH]
+
+RateOk:
+    /* Decrement quantum and verify it */
+    sub byte ptr [ebx+KTHREAD_QUANTUM], CLOCK_QUANTUM_DECREMENT
+    jg QuantumNotEmpty
+
+    /* Make sure this isn't the idle thread */
+    cmp ebx, [eax+KPCR_PRCB_IDLE_THREAD]
+    jz QuantumNotEmpty
+
+    /* Set quantum end */
+    mov byte ptr [eax+KPCR_PRCB_QUANTUM_END], 1
+    mov ecx, DISPATCH_LEVEL
+    call @HalRequestSoftwareInterrupt@4
+
+QuantumNotEmpty:
+    /* Restore ebx and return */
+    pop ebx
+    ret 4
+.endfunc
+
 .globl _KeUpdateSystemTime2@0
 .func KeUpdateSystemTime2@0
 _KeUpdateSystemTime2@0: