program running time comparison under Linux Desktop, Linux Server and Windows Xp
 

Hi guys!

A few days ago, I tried to run the same program under three different OS, one is Ubuntu 8.10 Desktop, one is Ubuntu 8.10 Server, and the other is Windows XP, and I got interesting result regarding the running time of the program, it took 1 hour to run under Windows, and took almost 2 hours to run under Ubuntu Desktop, and what is more ridiculous I think is that it took nearly 6 hours to run under Ubuntu Server and the machine running Ubuntu Server is actually much much better that the previous two, so what's wrong? I always think Linux should be more effective than Windows, and Linux server version should be more effective than Desktop version, am I wrong?

The program I ran is written in C++ and use only the standard C++ libraries.

the machines running Windows and Ubuntu Desktop are just ordinary PCs:
1. cpu: Intel(R) Core(TM)2 Duo CPU E4500 @ 2.20GHz
2. mem: 2G

the machine running Ubuntu Server is DELL PE 6800:
1. cpu: Intel(R) Xeon(TM) CPU 3.00GHz (16 cores)
2. mem: 32G

Any ideas? Thanks in advance!

Hello,
I think that difference between a desktop and a server version of linux is more in the stability / reliability than in the performance. More over performance depend on what you're looking at, I mean for example that system tick in a kernel desktop configuration is 1ms, but in a server it would be 10ms: so the desktop user will see a "smoother" system, but at the price of less raw power since you will sheduling 10 more times...
For the hardware, if your program doesn't use many memory space, you won't notice any difference between 2GB and 32GB.
The number of core make a difference if your application is multi-threaded, if not you'll use only one core...
A last word regarding of the compiler (and its option) you're using? With gcc try with optimization and architecture flag to get better performance.

Hmm, I think you're right, so I think I need to figure out what factors affect the performance of the kernel, do you have any suggestions? thanks!