diff --git a/src/crypto/rx/Rx_linux.cpp b/src/crypto/rx/Rx_linux.cpp
index 61f745848..33456333f 100644
--- a/src/crypto/rx/Rx_linux.cpp
+++ b/src/crypto/rx/Rx_linux.cpp
@@ -221,7 +221,10 @@ static bool wrmsr(const MsrItems& preset, const std::vector<CpuThread>& threads,
             else {
                 // Disable L3 cache for Class Of Service 1
                 if (!wrmsr_on_cpu(0xC91, cpu, 0, MsrItem::kNoMask)) {
-                    return false;
+                    // Some CPUs don't let set it to all zeros
+                    if (!wrmsr_on_cpu(0xC91, cpu, 1, MsrItem::kNoMask)) {
+                        return false;
+                    }
                 }
 
                 // Assign Class Of Service 1 to current CPU core
diff --git a/src/crypto/rx/Rx_win.cpp b/src/crypto/rx/Rx_win.cpp
index bac3d5166..82777462a 100644
--- a/src/crypto/rx/Rx_win.cpp
+++ b/src/crypto/rx/Rx_win.cpp
@@ -324,7 +324,12 @@ static bool wrmsr(const MsrItems &preset, const std::vector<CpuThread>& threads,
                 }
                 else {
                     // Disable L3 cache for Class Of Service 1
-                    success &= wrmsr(driver, 0xC91, 0, MsrItem::kNoMask);
+                    if (!wrmsr(driver, 0xC91, 0, MsrItem::kNoMask)) {
+                        // Some CPUs don't let set it to all zeros
+                        if (!wrmsr(driver, 0xC91, 1, MsrItem::kNoMask)) {
+                            success = false;
+                        }
+                    }
 
                     // Assign Class Of Service 1 to current CPU core
                     success &= wrmsr(driver, 0xC8F, 1ULL << 32, MsrItem::kNoMask);