TaskBatcher, for batching up memory-intensive parallel tasks. See http://geekswithblogs.net/EltonStoneman/archive/2013/12/09/batching-up-memory-intensive-parallel-tasks.aspx

TaskBatcher.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace Sixeyed.Framework
{
    public class TaskBatcher : IDisposable
    {
        private int _batchSize;
        private int _batchIndex = 0;
        private List<Task> _tasks = new List<Task>();

        public TaskBatcher(int batchSize)
        {
            _batchSize = batchSize;
        }

        public void Add(Action action)
        {
            if (_batchIndex == _batchSize)
            {
                Task.WaitAll(_tasks.ToArray());
                GC.Collect();
                _batchIndex = 0;
                _tasks = new List<Task>();
            }
            _tasks.Add(Task.Factory.StartNew(action));
            _batchIndex++;
        }

        public void Dispose()
        {
            if (_batchIndex > 0)
            {
                Task.WaitAll(_tasks.ToArray());
            }
        }
    }
}