SQL connection is too slow

We have a business web application in ASP.NET + SQL Server 2008.

In the beginning, SQL Server and IIS were on the same machine. Now we bought another machine. Current configuration is 开发者_开发技巧IIS machine plus SQL Server machine, and they are connected by a 1gb LAN connection.

With this configuration our web application is slower than before. Max bandwidth is 1-2% of network, about 15mbps.

When we use another threads to the same SQL Server from the same IIS machine, network use is higher. So this is no problem with SQL Server.

Ho we can make higher bandwidth for this SQL connection?

Specs:

• .Net 3.5
• SQL Server 2008 Standard
• file transfer can use 100% of LAN
• SQL connection by TCP/IP protocol
• SQL logins
• Pool tested with enable and disable
• Ado.Net by subsonic without LINQ

Use Sql Server Profiler to make sure you pool DB connections. You do cache DB query results, do you? Also make sure that the DB server has good enough hardware. There might also be some authentication or name resolution problems which are eventually resolved but will take time. These tends to cumulate, so many small delays will grow into big one.