diff --git a/core/unit_tests/helpers/default_hw_info.h b/core/unit_tests/helpers/default_hw_info.h
index 6f5114b2fb..fbdf0ad4ca 100644
--- a/core/unit_tests/helpers/default_hw_info.h
+++ b/core/unit_tests/helpers/default_hw_info.h
@@ -10,7 +10,6 @@
 
 namespace NEO {
 struct HardwareInfo;
-extern size_t numPlatformDevices;
 extern const HardwareInfo **platformDevices;
 
 } // namespace NEO
diff --git a/core/unit_tests/helpers/default_hw_info.inl b/core/unit_tests/helpers/default_hw_info.inl
index 1bc6ec4e79..ef499f6c2f 100644
--- a/core/unit_tests/helpers/default_hw_info.inl
+++ b/core/unit_tests/helpers/default_hw_info.inl
@@ -13,6 +13,5 @@ static const HardwareInfo *DefaultPlatformDevices[] = {
     &DEFAULT_TEST_PLATFORM::hwInfo,
 };
 
-size_t numPlatformDevices = arrayCount(DefaultPlatformDevices);
 const HardwareInfo **platformDevices = DefaultPlatformDevices;
 } // namespace NEO
diff --git a/unit_tests/api/cl_api_tests.h b/unit_tests/api/cl_api_tests.h
index 14f656bffb..da95fb7737 100644
--- a/unit_tests/api/cl_api_tests.h
+++ b/unit_tests/api/cl_api_tests.h
@@ -7,6 +7,7 @@
 
 #pragma once
 #include "core/execution_environment/root_device_environment.h"
+#include "core/unit_tests/helpers/debug_manager_state_restore.h"
 #include "runtime/api/api.h"
 #include "runtime/command_queue/command_queue.h"
 #include "runtime/tracing/tracing_api.h"
@@ -25,7 +26,6 @@ namespace NEO {
 class Context;
 class MockClDevice;
 struct RootDeviceEnvironment;
-extern size_t numPlatformDevices;
 
 template <uint32_t rootDeviceIndex = 1u>
 struct ApiFixture : PlatformFixture {
@@ -33,7 +33,7 @@ struct ApiFixture : PlatformFixture {
     ~ApiFixture() = default;
 
     virtual void SetUp() {
-        numDevicesBackup = numRootDevices;
+        DebugManager.flags.CreateMultipleRootDevices.set(numRootDevices);
         PlatformFixture::SetUp();
 
         if (rootDeviceIndex != 0u) {
@@ -67,7 +67,7 @@ struct ApiFixture : PlatformFixture {
 
         PlatformFixture::TearDown();
     }
-
+    DebugManagerStateRestore restorer;
     cl_int retVal = CL_SUCCESS;
     size_t retSize = 0;
 
@@ -77,7 +77,6 @@ struct ApiFixture : PlatformFixture {
     MockProgram *pProgram = nullptr;
     constexpr static uint32_t numRootDevices = maxRootDeviceCount;
     constexpr static uint32_t testedRootDeviceIndex = rootDeviceIndex;
-    VariableBackup<size_t> numDevicesBackup{&numPlatformDevices};
     cl_device_id testedClDevice = nullptr;
     std::unique_ptr<RootDeviceEnvironment> rootDeviceEnvironmentBackup;
 };
diff --git a/unit_tests/context/context_tests.cpp b/unit_tests/context/context_tests.cpp
index bcdace75f3..d6cba51b44 100644
--- a/unit_tests/context/context_tests.cpp
+++ b/unit_tests/context/context_tests.cpp
@@ -70,7 +70,6 @@ struct ContextTest : public PlatformFixture,
 };
 
 TEST_F(ContextTest, WhenCreatingContextThenDevicesAllDevicesExist) {
-    EXPECT_EQ(numPlatformDevices, context->getNumDevices());
     for (size_t deviceOrdinal = 0; deviceOrdinal < context->getNumDevices(); ++deviceOrdinal) {
         EXPECT_NE(nullptr, context->getDevice(deviceOrdinal));
     }
@@ -333,8 +332,7 @@ TEST(MultiDeviceContextTest, givenContextWithMultipleDevicesWhenGettingTotalNumb
     DebugManagerStateRestore restorer;
     const uint32_t numDevices = 2u;
     const uint32_t numSubDevices = 3u;
-    VariableBackup<size_t> numDevicesBackup(&numPlatformDevices);
-    numDevicesBackup = numDevices;
+    DebugManager.flags.CreateMultipleRootDevices.set(numDevices);
     DebugManager.flags.CreateMultipleSubDevices.set(numSubDevices);
     initPlatform();
     auto device0 = platform()->getClDevice(0);
diff --git a/unit_tests/libult/create_command_stream.cpp b/unit_tests/libult/create_command_stream.cpp
index 05a45d2011..278a58d95a 100644
--- a/unit_tests/libult/create_command_stream.cpp
+++ b/unit_tests/libult/create_command_stream.cpp
@@ -41,7 +41,7 @@ bool getDevices(size_t &numDevicesReturned, ExecutionEnvironment &executionEnvir
         executionEnvironment.setHwInfo(platformDevices[0]);
     }
     if (ultHwConfig.useMockedGetDevicesFunc) {
-        numDevicesReturned = numPlatformDevices;
+        numDevicesReturned = DebugManager.flags.CreateMultipleRootDevices.get() != 0 ? DebugManager.flags.CreateMultipleRootDevices.get() : 1u;
         executionEnvironment.prepareRootDeviceEnvironments(static_cast<uint32_t>(numDevicesReturned));
         executionEnvironment.calculateMaxOsContextCount();
         executionEnvironment.initializeMemoryManager();
diff --git a/unit_tests/main.cpp b/unit_tests/main.cpp
index c17a956be6..cac311765e 100644
--- a/unit_tests/main.cpp
+++ b/unit_tests/main.cpp
@@ -195,7 +195,6 @@ int main(int argc, char **argv) {
 #endif
 
     ::testing::InitGoogleMock(&argc, argv);
-    auto numDevices = numPlatformDevices;
     HardwareInfo device = DEFAULT_TEST_PLATFORM::hwInfo;
     ::productFamily = device.platform.eProductFamily;
 
@@ -217,11 +216,6 @@ int main(int argc, char **argv) {
                 testMode = TestMode::AubTestsWithTbx;
             }
             initialHardwareTag = 0;
-        } else if (!strcmp("--devices", argv[i])) {
-            ++i;
-            if (i < argc) {
-                numDevices = atoi(argv[i]);
-            }
         } else if (!strcmp("--rev_id", argv[i])) {
             ++i;
             if (i < argc) {
@@ -295,10 +289,6 @@ int main(int argc, char **argv) {
         }
     }
 
-    if (numDevices < 1) {
-        return -1;
-    }
-
     uint32_t threadsPerEu = hwInfoConfigFactory[productFamily]->threadsPerEu;
     PLATFORM platform;
     auto hardwareInfo = hardwareInfoTable[productFamily];
@@ -378,13 +368,8 @@ int main(int argc, char **argv) {
     }
 #endif
 
-    auto pDevices = new const HardwareInfo *[numDevices];
-    for (decltype(numDevices) i = 0; i < numDevices; ++i) {
-        pDevices[i] = &device;
-    }
-
-    numPlatformDevices = numDevices;
-    platformDevices = pDevices;
+    platformDevices = new const HardwareInfo *[1];
+    platformDevices[0] = &device;
 
     auto &listeners = ::testing::UnitTest::GetInstance()->listeners();
     if (useDefaultListener == false) {
@@ -462,7 +447,7 @@ int main(int argc, char **argv) {
 
     cleanTestHelpers();
 
-    delete[] pDevices;
+    delete[] platformDevices;
 
     return retVal;
 }