Up the max heap size from 512Mbytes to 700MBytes as an experiment.

src/heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 63 matching lines @@
       reserved_semispace_size_(2*MB),
       max_semispace_size_(2*MB),
       initial_semispace_size_(128*KB),
       max_old_generation_size_(192*MB),
       max_executable_size_(max_old_generation_size_),
       code_range_size_(0),
 #elif defined(V8_TARGET_ARCH_X64)
       reserved_semispace_size_(16*MB),
       max_semispace_size_(16*MB),
       initial_semispace_size_(1*MB),
-      max_old_generation_size_(1*GB),
+      max_old_generation_size_(1400*MB),
       max_executable_size_(256*MB),
       code_range_size_(512*MB),
 #else
       reserved_semispace_size_(8*MB),
       max_semispace_size_(8*MB),
       initial_semispace_size_(512*KB),
-      max_old_generation_size_(512*MB),
+      max_old_generation_size_(700*MB),
       max_executable_size_(128*MB),
       code_range_size_(0),
 #endif
 // Variables set based on semispace_size_ and old_generation_size_ in
 // ConfigureHeap (survived_since_last_expansion_, external_allocation_limit_)
 // Will be 4 * reserved_semispace_size_ to ensure that young
 // generation can be aligned to its size.
       survived_since_last_expansion_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
@@ skipping 6044 matching lines @@
 }
 
 
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 } }  // namespace v8::internal