diff --git a/Source/Core/Core/PowerPC/GDBStub.cpp b/Source/Core/Core/PowerPC/GDBStub.cpp
index 35f0ddbe23..5ab058ef82 100644
--- a/Source/Core/Core/PowerPC/GDBStub.cpp
+++ b/Source/Core/Core/PowerPC/GDBStub.cpp
@@ -761,6 +761,7 @@ static void WriteRegister()
       break;
     case 131:
       ppc_state.spr[SPR_MMCR0] = re32hex(bufptr);
+      PowerPC::MMCRUpdated(ppc_state);
       break;
     case 132:
       ppc_state.spr[SPR_PMC1] = re32hex(bufptr);
@@ -773,6 +774,7 @@ static void WriteRegister()
       break;
     case 135:
       ppc_state.spr[SPR_MMCR1] = re32hex(bufptr);
+      PowerPC::MMCRUpdated(ppc_state);
       break;
     case 136:
       ppc_state.spr[SPR_PMC3] = re32hex(bufptr);
diff --git a/Source/Core/Core/PowerPC/Gekko.h b/Source/Core/Core/PowerPC/Gekko.h
index 1acf6632f2..62a1743b45 100644
--- a/Source/Core/Core/PowerPC/Gekko.h
+++ b/Source/Core/Core/PowerPC/Gekko.h
@@ -930,6 +930,7 @@ enum CPUEmuFeatureFlags : u32
 {
   FEATURE_FLAG_MSR_DR = 1 << 0,
   FEATURE_FLAG_MSR_IR = 1 << 1,
+  FEATURE_FLAG_PERFMON = 1 << 2,
 };
 
 constexpr s32 SignExt16(s16 x)
diff --git a/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp b/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
index f4afeb6b96..8e8025cec9 100644
--- a/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
+++ b/Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
@@ -491,6 +491,11 @@ void Interpreter::mtspr(Interpreter& interpreter, UGeckoInstruction inst)
     }
     break;
 
+  case SPR_MMCR0:
+  case SPR_MMCR1:
+    MMCRUpdated(ppc_state);
+    break;
+
   case SPR_THRM1:
   case SPR_THRM2:
   case SPR_THRM3:
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit.cpp b/Source/Core/Core/PowerPC/Jit64/Jit.cpp
index 1b97ae1851..a6881c1172 100644
--- a/Source/Core/Core/PowerPC/Jit64/Jit.cpp
+++ b/Source/Core/Core/PowerPC/Jit64/Jit.cpp
@@ -337,7 +337,7 @@ void Jit64::FallBackToInterpreter(UGeckoInstruction inst)
   gpr.Flush();
   fpr.Flush();
 
-  if (js.op->opinfo->flags & FL_ENDBLOCK)
+  if (js.op->canEndBlock)
   {
     MOV(32, PPCSTATE(pc), Imm32(js.compilerPC));
     MOV(32, PPCSTATE(npc), Imm32(js.compilerPC + 4));
@@ -353,7 +353,7 @@ void Jit64::FallBackToInterpreter(UGeckoInstruction inst)
   gpr.Reset(js.op->regsOut);
   fpr.Reset(js.op->GetFregsOut());
 
-  if (js.op->opinfo->flags & FL_ENDBLOCK)
+  if (js.op->canEndBlock)
   {
     if (js.isLastInstruction)
     {
@@ -445,7 +445,6 @@ bool Jit64::Cleanup()
     did_something = true;
   }
 
-  // SPEED HACK: MMCR0/MMCR1 should be checked at run-time, not at compile time.
   if (MMCR0(m_ppc_state).Hex || MMCR1(m_ppc_state).Hex)
   {
     ABI_PushRegistersAndAdjustStack({}, 0);
diff --git a/Source/Core/Core/PowerPC/JitArm64/Jit.cpp b/Source/Core/Core/PowerPC/JitArm64/Jit.cpp
index 4f973f5c06..9474805972 100644
--- a/Source/Core/Core/PowerPC/JitArm64/Jit.cpp
+++ b/Source/Core/Core/PowerPC/JitArm64/Jit.cpp
@@ -187,7 +187,7 @@ void JitArm64::FallBackToInterpreter(UGeckoInstruction inst)
   gpr.Flush(FlushMode::All, ARM64Reg::INVALID_REG);
   fpr.Flush(FlushMode::All, ARM64Reg::INVALID_REG);
 
-  if (js.op->opinfo->flags & FL_ENDBLOCK)
+  if (js.op->canEndBlock)
   {
     // also flush the program counter
     ARM64Reg WA = gpr.GetReg();
@@ -207,7 +207,7 @@ void JitArm64::FallBackToInterpreter(UGeckoInstruction inst)
   fpr.ResetRegisters(js.op->GetFregsOut());
   gpr.ResetCRRegisters(js.op->crOut);
 
-  if (js.op->opinfo->flags & FL_ENDBLOCK)
+  if (js.op->canEndBlock)
   {
     if (js.isLastInstruction)
     {
@@ -276,7 +276,6 @@ void JitArm64::Cleanup()
     SetJumpTarget(exit);
   }
 
-  // SPEED HACK: MMCR0/MMCR1 should be checked at run-time, not at compile time.
   if (MMCR0(m_ppc_state).Hex || MMCR1(m_ppc_state).Hex)
   {
     ABI_CallFunction(&PowerPC::UpdatePerformanceMonitor, js.downcountAmount, js.numLoadStoreInst,
diff --git a/Source/Core/Core/PowerPC/JitCommon/JitCache.h b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
index 8c327c202e..feb872ee7b 100644
--- a/Source/Core/Core/PowerPC/JitCommon/JitCache.h
+++ b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
@@ -130,8 +130,8 @@ class JitBaseBlockCache
 {
 public:
   // The size of the fast map is determined like this:
-  // ((4 GiB guest memory space) / (4-byte alignment) * sizeof(JitBlock*)) << (2 feature flag bits)
-  static constexpr u64 FAST_BLOCK_MAP_SIZE = 0x8'0000'0000;
+  // ((4 GiB guest memory space) / (4-byte alignment) * sizeof(JitBlock*)) << (3 feature flag bits)
+  static constexpr u64 FAST_BLOCK_MAP_SIZE = 0x10'0000'0000;
   static constexpr u32 FAST_BLOCK_MAP_FALLBACK_ELEMENTS = 0x10000;
   static constexpr u32 FAST_BLOCK_MAP_FALLBACK_MASK = FAST_BLOCK_MAP_FALLBACK_ELEMENTS - 1;
 
diff --git a/Source/Core/Core/PowerPC/PPCAnalyst.cpp b/Source/Core/Core/PowerPC/PPCAnalyst.cpp
index f093863492..04d15b971e 100644
--- a/Source/Core/Core/PowerPC/PPCAnalyst.cpp
+++ b/Source/Core/Core/PowerPC/PPCAnalyst.cpp
@@ -202,6 +202,23 @@ static void AnalyzeFunction2(Common::Symbol* func)
   func->flags = flags;
 }
 
+static bool IsMtspr(UGeckoInstruction inst)
+{
+  return inst.OPCD == 31 && inst.SUBOP10 == 467;
+}
+
+static bool IsSprInstructionUsingMmcr(UGeckoInstruction inst)
+{
+  const u32 index = (inst.SPRU << 5) | (inst.SPRL & 0x1F);
+  return index == SPR_MMCR0 || index == SPR_MMCR1;
+}
+
+static bool InstructionCanEndBlock(const CodeOp& op)
+{
+  return (op.opinfo->flags & FL_ENDBLOCK) &&
+         (!IsMtspr(op.inst) || IsSprInstructionUsingMmcr(op.inst));
+}
+
 bool PPCAnalyzer::CanSwapAdjacentOps(const CodeOp& a, const CodeOp& b) const
 {
   const GekkoOPInfo* a_info = a.opinfo;
@@ -222,9 +239,11 @@ bool PPCAnalyzer::CanSwapAdjacentOps(const CodeOp& a, const CodeOp& b) const
   // [1] https://bugs.dolphin-emu.org/issues/5864#note-7
   if (a.canCauseException || b.canCauseException)
     return false;
-  if (a_flags & (FL_ENDBLOCK | FL_TIMER | FL_NO_REORDER | FL_SET_OE))
+  if (a.canEndBlock || b.canEndBlock)
     return false;
-  if (b_flags & (FL_ENDBLOCK | FL_TIMER | FL_NO_REORDER | FL_SET_OE))
+  if (a_flags & (FL_TIMER | FL_NO_REORDER | FL_SET_OE))
+    return false;
+  if (b_flags & (FL_TIMER | FL_NO_REORDER | FL_SET_OE))
     return false;
   if ((a_flags & (FL_SET_CA | FL_READ_CA)) && (b_flags & (FL_SET_CA | FL_READ_CA)))
     return false;
@@ -597,7 +616,7 @@ void PPCAnalyzer::SetInstructionStats(CodeBlock* block, CodeOp* code,
 
   code->wantsFPRF = (opinfo->flags & FL_READ_FPRF) != 0;
   code->outputFPRF = (opinfo->flags & FL_SET_FPRF) != 0;
-  code->canEndBlock = (opinfo->flags & FL_ENDBLOCK) != 0;
+  code->canEndBlock = InstructionCanEndBlock(*code);
 
   code->canCauseException = first_fpu_instruction ||
                             (opinfo->flags & (FL_LOADSTORE | FL_PROGRAMEXCEPTION)) != 0 ||
@@ -935,7 +954,7 @@ u32 PPCAnalyzer::Analyze(u32 address, CodeBlock* block, CodeBuffer* buffer,
     {
       // Just pick the next instruction
       address += 4;
-      if (!conditional_continue && opinfo->flags & FL_ENDBLOCK)  // right now we stop early
+      if (!conditional_continue && InstructionCanEndBlock(code[i]))  // right now we stop early
       {
         found_exit = true;
         break;
diff --git a/Source/Core/Core/PowerPC/PPCTables.cpp b/Source/Core/Core/PowerPC/PPCTables.cpp
index 9d70fb662b..8eeb5da076 100644
--- a/Source/Core/Core/PowerPC/PPCTables.cpp
+++ b/Source/Core/Core/PowerPC/PPCTables.cpp
@@ -374,7 +374,7 @@ constexpr std::array<GekkoOPTemplate, 107> s_table31{{
     {210, "mtsr", OpType::System, 1, FL_IN_S | FL_PROGRAMEXCEPTION},
     {242, "mtsrin", OpType::System, 1, FL_IN_SB | FL_PROGRAMEXCEPTION},
     {339, "mfspr", OpType::SPR, 1, FL_OUT_D | FL_PROGRAMEXCEPTION},
-    {467, "mtspr", OpType::SPR, 2, FL_IN_S | FL_PROGRAMEXCEPTION},
+    {467, "mtspr", OpType::SPR, 2, FL_IN_S | FL_ENDBLOCK | FL_PROGRAMEXCEPTION},
     {371, "mftb", OpType::System, 1, FL_OUT_D | FL_TIMER | FL_PROGRAMEXCEPTION},
     {512, "mcrxr", OpType::System, 1, FL_SET_CRn | FL_READ_CA | FL_SET_CA},
     {595, "mfsr", OpType::System, 3, FL_OUT_D | FL_PROGRAMEXCEPTION},
diff --git a/Source/Core/Core/PowerPC/PowerPC.cpp b/Source/Core/Core/PowerPC/PowerPC.cpp
index f83df655e5..b994b00f6e 100644
--- a/Source/Core/Core/PowerPC/PowerPC.cpp
+++ b/Source/Core/Core/PowerPC/PowerPC.cpp
@@ -137,7 +137,7 @@ void PowerPCManager::DoState(PointerWrap& p)
     }
 
     RoundingModeUpdated(m_ppc_state);
-    MSRUpdated(m_ppc_state);
+    RecalculateAllFeatureFlags(m_ppc_state);
 
     auto& mmu = m_system.GetMMU();
     mmu.IBATUpdated();
@@ -209,7 +209,7 @@ void PowerPCManager::ResetRegisters()
   SystemTimers::DecrementerSet();
 
   RoundingModeUpdated(m_ppc_state);
-  MSRUpdated(m_ppc_state);
+  RecalculateAllFeatureFlags(m_ppc_state);
 }
 
 void PowerPCManager::InitializeCPUCore(CPUCore cpu_core)
@@ -710,7 +710,27 @@ void MSRUpdated(PowerPCState& ppc_state)
   static_assert(FEATURE_FLAG_MSR_DR == 1 << 0);
   static_assert(FEATURE_FLAG_MSR_IR == 1 << 1);
 
-  ppc_state.feature_flags = static_cast<CPUEmuFeatureFlags>((ppc_state.msr.Hex >> 4) & 0x3);
+  ppc_state.feature_flags = static_cast<CPUEmuFeatureFlags>(
+      (ppc_state.feature_flags & FEATURE_FLAG_PERFMON) | ((ppc_state.msr.Hex >> 4) & 0x3));
+}
+
+void MMCRUpdated(PowerPCState& ppc_state)
+{
+  const bool perfmon = ppc_state.spr[SPR_MMCR0] || ppc_state.spr[SPR_MMCR1];
+  ppc_state.feature_flags = static_cast<CPUEmuFeatureFlags>(
+      (ppc_state.feature_flags & ~FEATURE_FLAG_PERFMON) | (perfmon ? FEATURE_FLAG_PERFMON : 0));
+}
+
+void RecalculateAllFeatureFlags(PowerPCState& ppc_state)
+{
+  static_assert(UReg_MSR{}.DR.StartBit() == 4);
+  static_assert(UReg_MSR{}.IR.StartBit() == 5);
+  static_assert(FEATURE_FLAG_MSR_DR == 1 << 0);
+  static_assert(FEATURE_FLAG_MSR_IR == 1 << 1);
+
+  const bool perfmon = ppc_state.spr[SPR_MMCR0] || ppc_state.spr[SPR_MMCR1];
+  ppc_state.feature_flags = static_cast<CPUEmuFeatureFlags>(((ppc_state.msr.Hex >> 4) & 0x3) |
+                                                            (perfmon ? FEATURE_FLAG_PERFMON : 0));
 }
 
 void CheckExceptionsFromJIT(PowerPCManager& power_pc)
diff --git a/Source/Core/Core/PowerPC/PowerPC.h b/Source/Core/Core/PowerPC/PowerPC.h
index 8a1701bb10..afcc0ac8bf 100644
--- a/Source/Core/Core/PowerPC/PowerPC.h
+++ b/Source/Core/Core/PowerPC/PowerPC.h
@@ -349,5 +349,7 @@ void CheckBreakPointsFromJIT(PowerPCManager& power_pc);
 
 void RoundingModeUpdated(PowerPCState& ppc_state);
 void MSRUpdated(PowerPCState& ppc_state);
+void MMCRUpdated(PowerPCState& ppc_state);
+void RecalculateAllFeatureFlags(PowerPCState& ppc_state);
 
 }  // namespace PowerPC