G400 Max and IRQ's

[BreadFan]

I keep hearing alot of people saying that their G400's need to be on IRQ 9 or higher. Could someone please tell me why (what is the reasoning behind this)? Thanks for you time.

------------------
BreadFan

Abit BH6, Celeron 300A @ 450 (sometimes, soon to be a PIII 500) SoundBlaster Live Value, 10.2gb IBM hard drive, 6.8gb Maxtor hard drive, Promise Ultra DMA 33 controller, Netgear FA310TX PCI Ethernet adapter and a freakin' awesome Matrox G400Max!!

[Kruzin]

It has to do with the way IRQs are used, or "activated", and the way Matrox cards use the IRQ.

IRQ 0-8 are edge activated.
IRQ 9-15 are level activated.
Matrox cards have always worked better on level activaded IRQs

[Jorden]

Hasn't it also to do with the AGP slot??

[mj12]

IRQ's are generally assigned as:
0 - System Timer
1- Keyboard
2 - redirected to 9
3 - com2/com4
4 - com1/com3
5 - lpt2 or sound card
6 - floppy disk controller
7 - lpt1
8 - real-time clock
9 - redirected to 2
10 - available
11 - available
12 - ps/2 mouse
13 - math coprocessor
14 - primary disk controller
15 - secondary disk controller

So you see that since irq's 9-15 are redirected through irq 2 then they have higher precedence than say irq 3. That is way you would want to have your spanking new video killer on 9+.


------------------
Get Paid to Surf the Web! <A HREF="http://www.alladvantage.com/home.asp?refid=CBM-295
" TARGET=_blank>http://www.alladvantage.com/home.asp?refid=CBM-295
</A>

[Zwisch]

Each IRQ has also priority over the BUS before other... The main line is : 0, 1, 2, 9, 10, 11, 12, 13, 14, 15, 3, 4, 5, 6, 7, 8 Hence giving a card an IRQ of 9 10 or 11 is the best thing to have since it will have priority over the other devices...

[Frank]

Yeah, I'm glad you asked that one Bread. I was curious about it myself. Though it hasn't seemed to be a problem for me as the G400 has aquired IRQ5 and no hiccups so far.


[This message has been edited by Frank (edited 16 October 1999).]

[Wombat]

Wow, I just decided to look, and I've got IRQ's to spare! Neat-o:

[rob@gnwy37 /proc]$ cat interrupts
CPU0
0: 4813225 XT-PIC timer
1: 64573 XT-PIC keyboard
2: 0 XT-PIC cascade
5: 1013760 XT-PIC soundblaster
8: 1 XT-PIC rtc
10: 639364 XT-PIC eth0
12: 822915 XT-PIC PS/2 Mouse
13: 1 XT-PIC fpu
14: 287722 XT-PIC ide0
15: 89071 XT-PIC ide1
NMI: 0

[paulcs]

You guys have unravelled one of the great mysteries of life for me. I'm saving this page.

Paul
paulcs@flashcom.net

[BreadFan]

OK, now that y'all have answered that, how do I get my Max on IRQ 9 or higher. Currently, my IRQ's are as follows:

00 System Timer
01 Keyboard
02 Interrupt Controller
03 Free
04 Free
05 G400 Max
05 IRQ Holder for PCI Steering
06 Floppy Disk
07 LPT1
08 CMOS/Real Time Clock
09 Free
10 SBLive Value
10 IRQ Holder for PCI Steering
11 NIC
11 USB Controller
11 IRQ Holder for PCI Steering
12 Promise Ultra33 Controller
12 IRQ Holder for PCI Steering
13 Numeric Data Processor
14 Intel 82371AB/EB PCI IDE Controller
14 Primary IDE Controller
15 Intel PCI IDE Controller
15 Secondary IDE

I have tried the rearranging bit (right now it is PCI0=empty, PCI1=Live Value, PCI2=NIC, PCI3=Promise Controller, PCI4 & 5=empty), the only one I can't try is PCI1=Promise controller because I have 2 hard drives connected to it and I cannot insert a card in the slot below it. I have to keep USB on because my mouse is USB. Thanks for your time.

------------------
BreadFan

Abit BH6, Celeron 300A @ 450 (sometimes, soon to be a PIII 500) SoundBlaster Live Value, 10.2gb IBM hard drive, 6.8gb Maxtor hard drive, Promise Ultra DMA 33 controller, Netgear FA310TX PCI Ethernet adapter and a freakin' awesome Matrox G400Max!!

[rickn]

put your usb on irq5 and g400 on irq 11

[Wombat]

BreadFAn,
If you're using the Promise card, are you also using the on-board IDE controllers? If not, you could turn some off and reclaim IRQs 14 and/or 15.

-Wombat

[Frank]

Hey Bread, I tried this last night after reading you thread (edited) and the helpful responses from others. It worked for me. And since you have an Abit mobo too, it should for you.
I noticed last night my IRQ 9 was free. So is yours.
Goto the bios, under PNP/PCI Configuration.
On the right hand side it lists the
PIRQ Use IRQ No. Auto
from 1 to 4.
Now I have nothing in the PCI slot next to my G400 so this worked for me. If you have something in that PCI slot I am not sure if this will work.(AGP and PCI slot1 apparently share IRQ)
Change the first setting from
PIRQ_1 Use IRQ No. :Auto
to
PIRQ_1 Use IRQ No. :9

Save and reboot.
LMK if this works for you as it has for me.
Thanks for bringing this topic up!
I had no prob at IRQ5 but everyone says IRQ9 and above and I had the opportunity so there!


[This message has been edited by Frank (edited 17 October 1999).]

[BreadFan]

Frank, you da man. Thanks for the info on how to put the card on IRQ 9. It worked like a charm. rickn, how do I change the IRQ for the USB controller? I've tried every way I know, but it will only stay at 11. Now that I have IRQ 5 available, it would rock to be able to put either the USB controller or the NIC on IRQ 5. If anyone has any insight on how to do this it would be greatly appreciated. Wombat, I am using the promise card and the onboard IDE ports, so I can't turn anything off. Thanks to everyone for the help, you guys RULE!!

------------------
BreadFan

Abit BH6, Celeron 300A @ 450 (sometimes, soon to be a PIII 500) SoundBlaster Live Value, 10.2gb IBM hard drive, 6.8gb Maxtor hard drive, Promise Ultra DMA 33 controller, Netgear FA310TX PCI Ethernet adapter and a freakin' awesome Matrox G400Max!!

[Gurm]

Breadfan:

The ABIT Mobo's work like this:

AGP0 + PCI1 = IRQA
PCI2 = IRQB
PCI3 = IRQC
PCI4 + PCI5 + USB = IRQD

So you can't make your USB stop sharing an IRQ with the NIC. But then again, who cares? Most NIC's share nice. Part of the PCI spec is sharing IRQ's, some cards just don't do it properly.

Now can anyone say for SURE that the IRQ's 9 and above get PRECEDENCE over 3-8? I always thought they were just level instead of edge... and the "redirect" thing is because certain ISA cards wouldn't let you have an IRQ other than 2, 3, 4, 5, 7... most notably MIDI cards.

- Gurm, who has been doing hardware for TOO MANY YEARS

------------------
G. U. R. M. It's not hard to spell, is it? Then don't screw it up!
The word "Gurm" is in no way Copyright 1999 Jorden van der Elst.

[Gum]

I have manually set my G400 on IRQ11 and USB Controller IRQ5 in my Award BIOS setup. This is due to stability reasons after many trial and errors.

However, Win98 insists that both G400 and USB should share IRQ11, and IRQ5 to be used only by SBLive! DOS Emulation.

Can IRQ5 be shared by both USB and SBLive! DOS Emulation? If yes, how? I do not want my G400 to share an IRQ and cause stability problems!!

BTW, I've no more spare IRQs...
Thanx!! :-D

------------------
AsusP5A rev1007, K6-400 o/c to 448 (112*4), 128Mb Micron PC100 -8E SDRAM, G400 OEM 16Mb AGP, IBM 16GP 8.4, Quantum ST 3.2A, Toshiba 32X CDROM, HP CDWriter 7570i, SBLive! Value, Intel EtherXpress Pro 100TX NIC, Motorola CableModem, RIC 17" Monitor, HP Deskjet 710C, Altec Lansing ACS45 & Cambridge PCWorks