64 latency for PCI bridge on an Abit BH6?

stodge · 08-08-2004, 08:41 AM

I get really crappy performance (hard disk, graphical, etc.) on my BH6 + P3700 under Linux, typically 40% slower than under Windows. The KDE info app shows the latency for the PCI bridge as 64. Is this typical?

Code:

cat pci
PCI devices found:
  Bus  0, device   0, function  0:
    Host bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 3).
      Master Capable.  Latency=32.
      Prefetchable 32 bit memory at 0xd0000000 [0xd7ffffff].
  Bus  0, device   1, function  0:
    PCI bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 3).
      Master Capable.  Latency=64.  Min Gnt=136.
  Bus  0, device   7, function  0:
    ISA bridge: Intel Corp. 82371AB/EB/MB PIIX4 ISA (rev 2).
  Bus  0, device   7, function  1:
    IDE interface: Intel Corp. 82371AB/EB/MB PIIX4 IDE (rev 1).
      Master Capable.  Latency=32.
      I/O at 0xf000 [0xf00f].
  Bus  0, device   7, function  2:
    USB Controller: Intel Corp. 82371AB/EB/MB PIIX4 USB (rev 1).
      IRQ 5.
      Master Capable.  Latency=32.
      I/O at 0xe000 [0xe01f].
  Bus  0, device   7, function  3:
    Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 2).
      IRQ 9.
  Bus  0, device  11, function  0:
    Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 48).
      IRQ 10.
      Master Capable.  Latency=32.  Min Gnt=10.Max Lat=10.
      I/O at 0xe400 [0xe47f].
      Non-prefetchable 32 bit memory at 0xe3000000 [0xe300007f].
  Bus  0, device  13, function  0:
    Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 4).
      IRQ 11.
      Master Capable.  Latency=32.  Min Gnt=2.Max Lat=20.
      I/O at 0xe800 [0xe81f].
  Bus  0, device  13, function  1:
    Input device controller: Creative Labs SB Live! MIDI/Game Port (rev 1).
      Master Capable.  Latency=32.
      I/O at 0xec00 [0xec07].
  Bus  1, device   0, function  0:
    VGA compatible controller: nVidia Corporation NV15 [GeForce2 GTS/Pro] (rev 163).
      IRQ 7.
      Master Capable.  Latency=248.  Min Gnt=5.Max Lat=1.
      Non-prefetchable 32 bit memory at 0xe0000000 [0xe0ffffff].
      Prefetchable 32 bit memory at 0xd8000000 [0xdfffffff].

Electro · 08-08-2004, 04:16 PM

Well KDE can slow down the computer to a crawl if you enable all the pretty effects. You can optimize the hard drive performance with hdparm. You can use iceWM or use XFCE. I have a Pentium II 400 MHz with 256 MB memory. It runs pretty fast with KDE but the resolution is set at 800x600 at 16-bit.

stodge · 08-08-2004, 08:28 PM

My PC doesn't run Linux "pretty fast" with any window manager, or at any resolution.

THanks

Electro · 08-09-2004, 12:19 AM

You probably have a lot of services running. Post what "top -bn1" and "/sbin/chkconfig --list" show and I or someone else can make some suggestions.

stodge · 08-09-2004, 10:58 AM

Quote:

Originally posted by Electro
You probably have a lot of services running. Post what "top -bn1" and "/sbin/chkconfig --list" show and I or someone else can make some suggestions.

Will do - thanks for the suggestion.

stodge · 08-10-2004, 06:51 PM

Does anyone know what the Min Gnt refers to in /proc/pci? Mine seems exceptionally high compared to others I've found on Google.

Quote:

Bus 0, device 1, function 0:
PCI bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 3).
Master Capable. Latency=64. Min Gnt=136.

Electro · 08-10-2004, 09:13 PM

If you really want to change the latency, you can use setpci. Though you can make your system unstable or not even work at all. The latency have to be in hexdecimal. If your system is stable, you can increase the latency on the IDE controller.

I do not know if nVidia has drivers for GeForce2. You may want to check.

The X Window Server does not have any 2D acceleration, so the word slow means nothing in Linux vs Windows. You can optimize the kernel with sysctl.conf to increase the efficiency of the filesystem, the network, and the memory. You can compile the kernel with a few options, so the kernel conserves less memory than before.