diff --git a/OpenSim/Region/Application/Application.cs b/OpenSim/Region/Application/Application.cs
index 0f90d37107..c3e7ec2e67 100644
--- a/OpenSim/Region/Application/Application.cs
+++ b/OpenSim/Region/Application/Application.cs
@@ -102,17 +102,50 @@ namespace OpenSim
             m_log.InfoFormat(
                 "[OPENSIM MAIN]: Environment variable MONO_THREADS_PER_CPU is {0}", monoThreadsPerCpu ?? "unset");
 
-            // Increase the number of IOCP threads available. Mono defaults to a tragically low number
+            // Verify the Threadpool allocates or uses enough worker and IO completion threads
+			// .NET 2.0 workerthreads default to 50 *  numcores
+			// .NET 3.0 workerthreads defaults to 250 * numcores
+			// .NET 4.0 workerthreads are dynamic based on bitness and OS resources
+			// Max IO Completion threads are 1000 on all 3 CLRs.
+			int workerThreadsMin = 500;
+			int workerThreadsMax = 1000; // may need further adjustment to match other CLR
+			int iocpThreadsMin = 1000;
+			int iocpThreadsMax = 2000; // may need further adjustment to match other CLR
             int workerThreads, iocpThreads;
             System.Threading.ThreadPool.GetMaxThreads(out workerThreads, out iocpThreads);
             m_log.InfoFormat("[OPENSIM MAIN]: Runtime gave us {0} worker threads and {1} IOCP threads", workerThreads, iocpThreads);
-            if (workerThreads < 500 || iocpThreads < 1000)
+            if (workerThreads < workerThreadsMin)
             {
-                workerThreads = 500;
-                iocpThreads = 1000;
-                m_log.Info("[OPENSIM MAIN]: Bumping up to 500 worker threads and 1000 IOCP threads");
-                System.Threading.ThreadPool.SetMaxThreads(workerThreads, iocpThreads);
+                workerThreads = workerThreadsMin;
+                m_log.InfoFormat("[OPENSIM MAIN]: Bumping up to worker threads to {0}",workerThreads);
             }
+            if (workerThreads > workerThreadsMax)
+            {
+                workerThreads = workerThreadsMax;
+                m_log.InfoFormat("[OPENSIM MAIN]: Limiting worker threads to {0}",workerThreads);
+            }
+			// Increase the number of IOCP threads available.
+			// Mono defaults to a tragically low number (24 on 6-core / 8GB Fedora 17)
+			if (iocpThreads < iocpThreadsMin)
+            {
+                iocpThreads = iocpThreadsMin;
+                m_log.InfoFormat("[OPENSIM MAIN]: Bumping up IO completion threads to {0}",iocpThreads);
+            }
+			// Make sure we don't overallocate IOCP threads and thrash system resources
+            if ( iocpThreads > iocpThreadsMax )
+            {
+                iocpThreads = iocpThreadsMax;
+                m_log.InfoFormat("[OPENSIM MAIN]: Limiting IO completion threads to {0}",iocpThreads);
+            }
+			// set the resulting worker and IO completion thread counts back to ThreadPool
+            if ( System.Threading.ThreadPool.SetMaxThreads(workerThreads, iocpThreads) )
+			{
+	            m_log.InfoFormat("[OPENSIM MAIN]: Threadpool set to {0} worker threads and {1} IO completion threads", workerThreads, iocpThreads);
+			}
+			else
+			{
+	            m_log.Info("[OPENSIM MAIN]: Threadpool reconfiguration failed, runtime defaults still in effect.");				
+			}
 
             // Check if the system is compatible with OpenSimulator.
             // Ensures that the minimum system requirements are met