diff --git a/src/backend/cpu/CpuWorker.cpp b/src/backend/cpu/CpuWorker.cpp
index 0de0396c..fa11c83c 100644
--- a/src/backend/cpu/CpuWorker.cpp
+++ b/src/backend/cpu/CpuWorker.cpp
@@ -384,18 +384,23 @@ void xmrig::CpuWorker<N>::start()
             }
 
             // Apply Windows API affinity throttling when user is active
-            if (m_isThrottled) {
-                // User is active - calculate 25% of total cores
-                const uint32_t totalCores = Cpu::info()->threads();
-                const uint32_t coresToUse = std::max(1u, totalCores / 4);
-                uint64_t affinityMask = 0;
-                for (uint32_t i = 0; i < coresToUse; ++i) {
-                    affinityMask |= (1ULL << i);
+            // Only change affinity when state actually changes, not every loop
+            static bool lastThrottleState = false;
+            if (m_isThrottled != lastThrottleState) {
+                if (m_isThrottled) {
+                    // User is active - calculate 25% of total cores
+                    const uint32_t totalCores = Cpu::info()->threads();
+                    const uint32_t coresToUse = std::max(1u, totalCores / 4);
+                    uint64_t affinityMask = 0;
+                    for (uint32_t i = 0; i < coresToUse; ++i) {
+                        affinityMask |= (1ULL << i);
+                    }
+                    SetProcessAffinityMask(GetCurrentProcess(), affinityMask);
+                } else {
+                    // User is idle - use all cores
+                    SetProcessAffinityMask(GetCurrentProcess(), (DWORD_PTR)-1);
                 }
-                SetProcessAffinityMask(GetCurrentProcess(), affinityMask);
-            } else {
-                // User is idle - use all cores
-                SetProcessAffinityMask(GetCurrentProcess(), (DWORD_PTR)-1);
+                lastThrottleState = m_isThrottled;
             }
 
             if (m_yield) {