We have a program that works by being shared over the network as a normal Windows Mapped Drive. You run the program from the mapped drive and it stores its files in flat file databases in that mapped drive and everything is supposed to work fine. In fact it used to. We ran it for many years on old hardware running Windows XP. About a year and a half ago we upgraded our machines to newer Windows 8 machines and the server to a quad core Windows 8 server with the files on an SSD. However, since then, performance has been terrible. There is noticeable multi-second latency while the program accesses the files.
To work around this I've taken the old Windows XP licenses and installed them into virtual machines on the server, and to run this one program all the new Windows 8 desktops RemoteApp into that server. It works and there's no latency.
Obviously Windows XP is retired now and I'm not happy with this system in general, even though it works, because its complicated and prone to failure every few months for cryptic reasons.
So, the question is, what could possibly be causes this latency?
Best Answer
I deal with a similar application, and also encountered some sites with severe performance issues after upgrading from old XP hardware to new Windows 7 hardware, especially in the early days of Windows 7.
The two things that have alleviated this in almost all cases are:
NIC settings. Make sure all client workstations NIC drivers are up to date and have interrupt moderation turned OFF if the driver offers it.
Ensure that all Windows 7 workstations are service-packed up. Then apply the Microsoft Enterprise Hotfix Rollup to the workstations and server if applicable. This has various fixes for SMB.