Program.cs

class Program
{
    static void Main(string[] args)
    {
        var connectionMultiplexer = ConnectionMultiplexer.Connect("localhost:6379");

        var redis = connectionMultiplexer.GetDatabase(db: 1);

        const int keyCount = 10000;
        var random = new Random();

        var keys = Enumerable.Range(0, keyCount).Select(i =>
        {
            var keyLength = random.Next(100, 5000);
            return MakeRandomKey(random, keyLength);
        }).ToList();

        var sw = new Stopwatch();
        sw.Start();
        for (int i = 0; i < keys.Count; i++)
        {
            var key = keys[i];
            redis.StringSet(key, "value");
        }
        sw.Stop();

        Console.WriteLine("Done.");
        Console.WriteLine("Time Taken: {0}", sw.Elapsed.ToString());
        Console.Read();
    }

    static string MakeRandomKey(Random random, long length)
    {
        const string keyChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        var stringChars = new char[length];

        for (int i = 0; i < stringChars.Length; i++)
        {
            stringChars[i] = keyChars[random.Next(keyChars.Length)];
        }

        return new String(stringChars);
    }
}