Impact of (kernel+XFREE+WM) on performances?

Impact of (kernel+XFREE+WM) on performances?

Post by Marco Fiorett » Wed, 31 Oct 2001 01:21:06


couldn't sleep last night, and came to ask myself the following
question, which I now pass here. Any feedback is welcome.

Imagine having your linux desktop open, with several (heavy) user
space applications running, locally and over the network.

For example, the Gimp is applying some filter to a large image and
redrawing it, StarCalc is updating totals and graphs inside a big
spreadsheet, some ftp is ongoing, and you are browsing your Imap
folders on the server.

In such a context, how much does the triplet "modern kernel, Xfree and
your_preferred_window_manager_here"  "impact" on overall performance?
In other words, of 1000 CPU clock cycles, how many would be spent
actual application code in the CPU, and how many for all the system
or just waiting for interrupts?

By "system" here I refer to *everything* else: process scheduling,
swapping, file system management/journalling, loading instruction into
the CPU, loading data to and from disk, redrawing the screen and all the
other window manager stuff, keep all the TCP/IP/PPP/firewalling
going, etc..

Of course, without a multitasking kernel with networking included and
a windowing system nothing would happen at all, but I'd really like to
figure out exactly what "price" we pay for it, just out of curiosity.

I have tried to sum all the processes ran by root on my workstation,
and came out with system stuff requiring 0.8% of CPU, 9.6% of RAM. Is
this the right answer to my question, or there is a better way to
calculate this?




1. Xfree Performance vs. Accelerated-X Performance

        It seems that many people here buy a commercial X-server like
Accelerated-X simply because it will support their video card (ex.
Matrox Millenium) but does anyone have information that compares the speed
of the X-server software to that of the drivers that Xfree86 comes with? I
would assume that the Accelerated-X drivers may be superior coming from
XInside; but by how much, and in what areas?

Cols, Oh

2. HELP! No printer connection with PCNFS pro

3. Sys Accounting and performance impact???

4. select call and signal call

5. Interleave factor performance impact

6. Same IRQ for sound and Modem of IRQ 5

7. potential performance impact question

8. pilot-mail does nothing but segmentation fault

9. Q: performance impact of log. interf.

10. NFS Performance Impact

11. Impact of process accounting on system performance

12. Linux netfilter/iptables firewall : impacts on performances ?

13. smptimers - performance impact