Windows vs Linux execution speed.

[Pretz]

I have an application build in C++, which is portable on Win and Linux. It's a communication node between other two applications, and it's using UDP as streaming.

The problem is that the entire installation is running faster when this node runs on Windows, and much slower when it's on Linux. All it has to do, is to listen on a UDP port, and sent received data on an other UPD port. But it's running tree or four time slower on Linux, I can't figure it out why.

Weird thing is when this node is running on Linux Virtual Machine (Ubuntu) which is hosted by a Windows machine, it's running as fast as it would be on a Windows box natively. So, I'm thinking that it's a network configuration problem...

Does anyone know what would be the reason. Anyone found a similar behaviour?

Thanks.

[rdrast]

Wide open field there.
It could be anything from hardware, to cables, to configurations, to having 'Auto-negotiate' turned off somewhere to the protocol stack, to memory, to ... well, you get the picture?

Start first by running some simple raw speed tests on both boxes, see how they behave.

Note: Run the tests locally in controlled circumstances, not a test site on the net. Even just copying a large file from both boxes to a 'Test' machine over the network might show something.

[Pretz]

The Linux or the Windows is running on same machine, as dual boot. So the hw is the same. Copying files works fine, I mean, with a 100Mbps NIC I have around 7MBytes/s. I think it's fine. I cant test it locally, because the other two applications (client and server) are running only on Windows.

I tried to test them all on same machine with Windows plus a Virtual Machine with Linux for the node. The speed seems to be fine. This is something that I cant understand.

The "Auto-negotiate" doesn't apply only for TCP? Coz I'm using only UDP for communication.

Thanks...