Is it better to execute a file over the network or copy it locally first?

My winforms app needs to run an executable that's sitting on a share. The exe is about 50MB (it's a setup.exe type of file). My app will run on many different machines/networks with varying speeds (some fast, but some awfully slow, like barely 10baseT speeds).

Is it better to execute the file 开发者_运维技巧straight from the share or is it more efficient to copy it locally and then execute it? I am talking in terms of annoying the user the least.

Locally is better. A copy will read each byte of the file a single time, no more, no less. As you execute, you may revisit code that is out of cache, etc and gets pulled again.

As a setup program, I would assume that the engine will want to do some kind of CRC or other integrity check too, which means it's reading the entire file anyway.

It is always better to execute it locally than running it over the network.

If you're application is small, and does not need to load many different resource during runtime then it is ok to run it over the network. It might even be preferable because if you run it over the network the code is read (download and load to memory) once as oppose of manually downloading the file then run it which take 2 read code. For example you can run a clock widget application over the network.

On the other hand, if your application does read a lot of resources during runtim, then it is absolutely a bad idea to run it over the network because each read of the resource will go over the network, which is very slow. For example, you probably don't want to be running Eclipse over the network.

Another factor to take into consideration is how many concurrent user will be accessing the application at the same time. If there are many, you should copy the application to local and run from there.

I believe the OS always copy the file to a local temp folder before it is actually executed. There are no round trips from/to the network after it gets a copy, it only happens once. This is sort of like how a browser works... it first retrieves the file, saves it locally, then it runs if off of the local temp where it saved it. In other words, there is no need to copy it manually unless you want to keep a copy for yourself.