Realize the same function of the code. like this(run environment: cpu:E5300,Memory:4GB ,win2008R2 x64):

class Program
{
static void Main(string[] args)

{ UseMongoDbDriver1_5_0_Test(); UseMongoDbDriver1_8_2_Test(); Console.Read(); }

static void UseMongoDbDriver1_8_2_Test()
{
var client = new MongoClient();
var server = client.GetServer();
Stopwatch st = new Stopwatch();
st.Start();
var result = server.GetDatabase("Test").GetCollection("Product").FindAll().SetLimit(10).ToList();
st.Stop();
Console.WriteLine("Driver v1.8.2 QueryResult ToList ElapsedTime:

{0} ms", st.ElapsedMilliseconds);
//output: Driver v1.5.0 QueryResult ToList ElapsedTime: 1445 ms
}

static void UseMongoDbDriver1_5_0_Test()
{
MongoServer server = MongoServer.Create("mongodb://127.0.0.1:27017/Test");
MongoDatabase db = MongoDatabase.Create("mongodb://127.0.0.1:27017/Test");
using (server.RequestStart(db))
{
Stopwatch st = new Stopwatch();
var result = db.GetCollection("Product").FindAll().SetLimit(10).ToList();
st.Stop();
Console.WriteLine("Driver v1.5.0 Query Result ToList ElapsedTime: {0}

ms", st.ElapsedMilliseconds);
}
//output: Driver v1.5.0 QueryResult ToList ElapsedTime: 0 ms
}
}

that maybe a bug. driver v1.5.0 query result faster than v1.8.2 ?