Abit VT7
Contents
Features
Abit has moved the VT7 to the product archive. If you have an old Celeron CPU laying around this motherboard may be of interest.
- Form Factor
- ATX (305 x 225 mm)
- Socket
- 478
I have Abit VT7 v2.0 motherboard on my 0.20 backend system with FC6.
Update Jan 2009: This system has now been updated to 0.21 and Ubuntu 8.04. Related mythtv blog postings are in this link http://noppatech.wordpress.com/tag/mythtv/.
- Processor
- Supports Intel Pentium® 4/Celeron Socket 478 processors (800/533/400MHz FSB)
- Chipset
- VIA PT880 / VT8237 chipset
- 5 x PCI slots
Issues
My Myth backend kept randomly crashing/rebooting usually when I was recording something (high CPU usage and high network activity). I have PVR-150 and PVR-250 on my system.
First I thought this was a XFS issue with FC6 kernel. Or ACPI issue or over-heating issue.
I spent quite a few moments reading mythtv mailing list archives and tried this in /etc/sysctl.conf. It is also mentioned in Jared's guide.
#for making ivtv happier with memory usage: vm.min_free_kbytes = 16384
I also found this XFS file system tuning advise for /etc/sysctl.conf from mailing list:
vm.dirty_ratio = 50 vm.dirty_background_ratio = 5
None of them fully resolved the issue. Random reboots became less frequent though.
Then somebody wrote in the mailing list that disabling on-board NIC is a good idea in situations like this.
I also increased PCI latency on nvidia and eth0 devices and added ethtool command in /etc/rc.local.
See this link http://www-128.ibm.com/developerworks/linux/library/l-hw2.html
This link might help to tweak TCP settings.
[root@hippo ~]# lspci 00:00.0 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:00.1 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:00.2 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:00.3 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:00.4 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:00.7 Host bridge: VIA Technologies, Inc. PT880 Host Bridge 00:01.0 PCI bridge: VIA Technologies, Inc. VT8237 PCI Bridge 00:09.0 Multimedia video controller: Internext Compression Inc iTVC16 (CX23416) MPEG-2 Encoder (rev 01) 00:0b.0 Ethernet controller: National Semiconductor Corporation DP83815 (MacPhyter) Ethernet Controller 00:0c.0 Multimedia video controller: Internext Compression Inc iTVC16 (CX23416) MPEG-2 Encoder (rev 01) 00:0f.0 RAID bus controller: VIA Technologies, Inc. VIA VT6420 SATA RAID Controller (rev 80) 00:0f.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06) 00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.4 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 86) 00:11.0 ISA bridge: VIA Technologies, Inc. VT8237 ISA bridge [KT600/K8T800/K8T890 South] 00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 60) 01:00.0 VGA compatible controller: nVidia Corporation NV34 [GeForce FX 5200] (rev a1) [root@hippo ~]# ca[root@hippo ~]# cat /etc/rc.local #!/bin/sh # # This script will be executed *after* all the other init scripts. # You can put your own initialization stuff in here if you don't # want to do the full Sys V style init stuff. touch /var/lock/subsys/local /usr/bin/mtd --daemon # # Source: # http://www-128.ibm.com/developerworks/linux/library/l-hw2.html # setpci -v -d *:* latency_timer=b0 setpci -v -s 00:11.5 latency_timer=ff setpci -v -s 00:0c.0 latency_timer=ff ethtool -s eth0 autoneg off speed 100 duplex full [root@hippo ~]#
Then I did RTFM on VT7 manual and I found this on page 60:
"PCI slot 1 shares signals with PCI slot 5, AGP slot and LAN."
So I disabled on-board LAN and installed PCI LAN so that it is on PCI slot 4. PVR-150 is now on PCI slot 5.
Now my interrupts are like this (eth0 has it own IRQ).
[root@hippo ~]# cat /proc/interrupts
CPU0 CPU1
0: 255474390 0 IO-APIC-edge timer
1: 11 1456 IO-APIC-edge i8042
7: 0 0 IO-APIC-edge parport0
8: 1 0 IO-APIC-edge rtc
9: 0 0 IO-APIC-fasteoi acpi
12: 478 0 IO-APIC-edge i8042
14: 8723 306873 IO-APIC-edge ide0
15: 22703421 0 IO-APIC-edge ide1
16: 268 206059 IO-APIC-fasteoi libata
17: 177 0 IO-APIC-fasteoi uhci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb4, ehci_hcd:usb5
18: 1333095 0 IO-APIC-fasteoi ivtv0
19: 2353 20253892 IO-APIC-fasteoi ivtv1, nvidia
20: 1 384618 IO-APIC-fasteoi VIA8237
21: 324 9530603 IO-APIC-fasteoi eth0
NMI: 0 0
LOC: 255477872 255260190
ERR: 0
MIS: 0
[root@hippo ~]#
Earlier they were like this where eth0 and NVIDIA FX-5200 were sharing the same IRQ.
LOC: 125702364 125842813
ERR: 0
MIS: 0
CPU0 CPU1
0: 801567 0 IO-APIC-edge timer
1: 15 1677 IO-APIC-edge i8042
7: 0 0 IO-APIC-edge parport0
8: 1 0 IO-APIC-edge rtc
9: 0 0 IO-APIC-fasteoi acpi
12: 137 7262 IO-APIC-edge i8042
14: 6651 14357 IO-APIC-edge ide0
15: 22595 0 IO-APIC-edge ide1
16: 229 10882 IO-APIC-fasteoi libata
17: 1197 0 IO-APIC-fasteoi uhci_hcd:usb1, uhci_hcd:usb2, uhc
i_hcd:usb3, uhci_hcd:usb4, ehci_hcd:usb5
18: 2553 77802 IO-APIC-fasteoi eth0, nvidia
19: 0 0 IO-APIC-fasteoi VIA8237
20: 0 0 IO-APIC-fasteoi ivtv0
21: 0 0 IO-APIC-fasteoi ivtv1
NMI: 0 0
LOC: 801416 801433
ERR: 0
MIS: 0
Now my system is 100% stable.
BIOS
I'm running latest VT7 BIOS 14 with fairly "standard" settings.
Links
Manufacturer's product page for VT7: http://abit-usa.com/products/mb/search.php?model=vt7
