diff --git a/router/java/src/net/i2p/router/transport/ntcp/EventPumper.java b/router/java/src/net/i2p/router/transport/ntcp/EventPumper.java
index 2a0824bf7..42e76440c 100644
--- a/router/java/src/net/i2p/router/transport/ntcp/EventPumper.java
+++ b/router/java/src/net/i2p/router/transport/ntcp/EventPumper.java
@@ -73,7 +73,6 @@ class EventPumper implements Runnable {
         }
     }
     
-    private static final TryCache<ByteBuffer> _bufferCache = new TryCache<>(new BufferFactory(), MAX_CACHE_SIZE);
 
     /** 
      * every few seconds, iterate across all ntcp connections just to make sure
@@ -105,6 +104,8 @@ class EventPumper implements Runnable {
         long maxMemory = SystemVersion.getMaxMemory();
         MIN_BUFS = (int) Math.max(MIN_MINB, Math.min(MAX_MINB, 1 + (maxMemory / (16*1024*1024))));
     }
+    
+    private static final TryCache<ByteBuffer> _bufferCache = new TryCache<>(new BufferFactory(), MIN_BUFS);
 
     public EventPumper(RouterContext ctx, NTCPTransport transport) {
         _context = ctx;
diff --git a/router/java/src/net/i2p/router/transport/udp/UDPPacket.java b/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
index a88020ced..ca7380532 100644
--- a/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
+++ b/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
@@ -57,11 +57,14 @@ class UDPPacket implements CDQEntry {
     private static final TryCache<UDPPacket> _packetCache;
     private static final TryCache.ObjectFactory<UDPPacket> _packetFactory;
     private static final boolean CACHE = true;
+    private static final int MIN_CACHE_SIZE = 64;
     private static final int MAX_CACHE_SIZE = 256;
     static {
         if (CACHE) {
+            long maxMemory = SystemVersion.getMaxMemory();
+            int csize = (int) Math.max(MIN_CACHE_SIZE, Math.min(MAX_CACHE_SIZE, maxMemory / (1024*1024)));
             _packetFactory = new PacketFactory();
-            _packetCache = new TryCache<>(_packetFactory, MAX_CACHE_SIZE);
+            _packetCache = new TryCache<>(_packetFactory, csize);
         } else {
             _packetCache = null;
             _packetFactory = null;