Index: /trunk/src/VBox/Runtime/r0drv/nt/mp-r0drv-nt.cpp
===================================================================
--- /trunk/src/VBox/Runtime/r0drv/nt/mp-r0drv-nt.cpp	(revision 53764)
+++ /trunk/src/VBox/Runtime/r0drv/nt/mp-r0drv-nt.cpp	(revision 53765)
@@ -436,5 +436,6 @@
               : VERR_CPU_OFFLINE;
 
-    if (g_pfnrtKeIpiGenericCall)
+    if (   g_pfnrtKeIpiGenericCall
+        && RTMpGetOnlineCount() <= 2)
         return rtMpCallUsingBroadcastIpi(pfnWorker, pvUser1, pvUser2, rtmpNtOnSpecificBroadcastIpiWrapper, 0);
     return rtMpCallUsingDpcs(pfnWorker, pvUser1, pvUser2, RT_NT_CPUID_SPECIFIC, idCpu);