diff -ur icecat-31.4.0.orig/mobile/android/base/util/ThreadUtils.java icecat-31.4.0/mobile/android/base/util/ThreadUtils.java
--- icecat-31.4.0.orig/mobile/android/base/util/ThreadUtils.java	2015-02-22 18:35:21.022789023 +0000
+++ icecat-31.4.0/mobile/android/base/util/ThreadUtils.java	2015-02-22 22:09:50.518544343 +0000
@@ -179,7 +179,13 @@
      * @param timeout Timeout in ms after which the priority will be reset
      */
     public static void reduceGeckoPriority(long timeout) {
-        if (!sIsGeckoPriorityReduced) {
+        if (Runtime.getRuntime().availableProcessors() > 1) {
+            // Don't reduce priority for multicore devices. We use availableProcessors()
+            // for its fast performance. It may give false negatives (i.e. multicore
+            // detected as single-core), but we can tolerate this behavior.
+            return;
+        }
+        if (!sIsGeckoPriorityReduced && sGeckoThread != null) {
             sIsGeckoPriorityReduced = true;
             sGeckoThread.setPriority(Thread.MIN_PRIORITY);
             getUiHandler().postDelayed(sPriorityResetRunnable, timeout);