DAW ReBuild Nightmare - Did I Corner Myself?

W2K and XP are a in corner for sure.
(never to come out again IMO).

W2K and XP aren't the problem, I only mentioned that in case there was something that could be done under those OS's.
 
Yeah, I don't understand mass piling onto the same IRQ either, but apparently it can happen.  This is what occurs when people try to make machine people-proof.  The whole PnP concept was borked from day one IMO, at least regarding the whole interrupt/IRQ buss situation.  

I recently changed my system board and was shocked to find a setting to reserve an IRQ for a com port in the bios. I haven't seen that in a long time. However, I haven't had an issue with the virtual IRQ's either.
 
It has been a while since I had XP but IIRC you can reserve/define/config the first four com ports in the control panel. Also, most software I have seen that supports com ports allows you to select one as well.

One other thought crossed my mind...what about PCIe ?  There is one PCIe slot, maybe I should get a PCIe Firewire card instead?   I'm not entirely up on all this but I think maybe PCIe would  "separate" the card from any PCI device interrupt/IRQ collisions?
 
Did I mention I hate computers?

It's not today's hardware, it's using an Intel board circa 2012-ish (I think) that still has driver support for W2K & XP.  Works awesome.  I reconstructed the thing using onboard audio until I got everything figured out and was prepping for the final step of putting a firewire card in for the audio interface and that's when I suddenly realized there's a potential problem with the way the mobo and OS are mapping/handling devices. 

In the BIOS, disable everything you don't need on the board.  That frees up IRQs.  The result: less sharing.

Argh!!!  I got the PCIe FIrewire card and Windows is STILL assigning the SAME IRQ to it !!!   
Everything is jammed on IRQ16, even though there are open IRQ's to be used.   Fireface 400, onboard audio, PCI busses, USB busses, onboard Video.... it's all jammed on IRQ16.    THIS CANNOT POSSIBLY BE SAFE for a DAW is what I maintain.   The one thing I did notice however is that all these other entities are on "PCI Bus 0" whereas the PCIe Firewire card is listed as being on "Bus 2".   So that's probably a good sign.  But still, having assigned the same IRQ....WHY!?
 
Does anybody have any ideas at all about how to force Windows to use one of the open IRQ's, or to set it manually??   I'm already using the only PCIe slot, so moving the card isn't an option.
 
This is the LAST issue remaining, I would hate for it to cause me to scrap this whole effort and move to another motherboard simply to be able to control the IRQ settings.  I just never anticipated Windows would be so brain-dead.
 
    Sonic

On shared IRQ's, there is a priority order.  If the device you want is the primary device it will have priority use over the other(s).  
 
Its been a while since I've had and used XP, but I recall being able to manually assign open IRQ's to devices.  I remember doing this in the Device Manager for the specific device.  
 

No, this is a very real concern.  And just because something might not be obvious up front doesn't mean it isn't a trainwreck waiting to happen in the midst of a session.  There is a misunderstanding in thinking the whole IRQ issue has been solved by modern BIOS and Windows enhancements.  Granted it is not quite the same type of concern as back in the day prior to W2K with IRQ conflicts, but it is still a very real concern.  There are two levels of things going on, one is the actual interrupt layout at the physical board design layer, the other is the IRQ assignment.  Even when using APIC, if things are lumped onto a single IRQ it seems that is still asking for trouble.  Every device still has to service an inquiry to see who is supposed to service the interrupt.  The more devices on the same IRQ, the more queries, and the higher likelihood if anybody does not behave properly & expeditiously there can be negative impacts to audio streams.
 
If somebody can explain how this is NOT a concern, please do so, I'm interested to learn why you feel what I've stated isn't valid.
 
Here is the Intel manual WRT the controller involved: https://www.intel.com/content/www/us/en/io/i-o-controller-hub-7-datasheet.html
For more detail look at sections on pages 43, 62 and 140.   I'm trying to decipher all this still so any help is appreciated.   From what I can see so far, it does seem in APIC mode most single-trigger entities will end up on IntA and IRQ16.   I can't believe there isn't some way to have at least ONE isolated card/bus.  Every board used to have this ability back in the day.  I'm also perplexed why open legacy IRQ's below 16 seem like they can't be used.   Anyway, this is a bit over my head so maybe some of the techy guru's on the forum can figure this out... 
 
Sonic

fireberd
My PCIe Firewire card is assigned IRQ16.  It works perfect and I have no dropouts with my MOTU896Mk3 Hybrid recording interface connected to it.
There are other devices, such as "High Definition Audio Bus" also assigned to IRQ16

 
Thanks for the reply.  What exactly is on your IRQ16..... USB, Video, Audio, etc.... Anything actually being used on IRQ16 besides the Firewire card?

Thanks guys, will try to catch up with some responses....
 
- I did already disable everything possible in the BIOS that wasn't needed. 
- There isn't a way in the BIOS to set interrupts at all (which I find pathetic given my 2001 DELL machine had this support and here I am using an Intel board almost 10 years newer that now doesn't have that ability?)
- There isn't a way in the BIOS to disable PnP / APIC mode.
- There is no way to alter IRQ's in W2K/XP if in APIC mode to my knowledge.
- In theory I could try to go to Standard PC mode but I am still unclear about whether this will work for dual core CPU. I read that it won't work for multi-processor machines but it wasn't entirely clear if that mean 2 physical CPU's or anything more than single core.
 
@bvideo: Are you implying there isn't any bottleneck in IRQ processing?  DPC or not, a device cannot be interrupted again before it has completed it's "ISR" routine.  The IRQ is the trigger for this unless I'm mistaken.  Either the INT lines (A-D) and/or the IRQ are still real, no matter how implemented.  If there are multiple devices (Video, Audio, PCI Bridges, Firewire Card, USB port) all on the same IRQ, and many even sharing the same INT line, that's got to be a problem as far as I can decipher so far.
 
BTW, I did notice another perplexing thing in the DevMgr view: There are two devices listed under IRQ16 that are called "Standard PCI to PCI Bridge".  These are not in any of my older machines.  What are these things??  The Firewire card is actually "on" one of these, yet also takes up an IRQ (again IRQ16).  Why are these "bridges" listed as devices?? Is this some kind of new motherboard design aspect that happened in more recent years?   (Intel G41 Chipset)
 
Sonic

In my IRQ16 list  3 out of the 4 listed controllers are PCIe devices.
The TI 1394 OHCI Compliant Host Controller is my PCIe Firewire card
I have two PCIe 5 port USB 2.0 cards and they are the NEC PCI to USB Open Host Controller and the Standard Enhanced PCI to USB Host Controller.
 
I needed the extra USB ports and I reused the USB port expansion cards from my old PC.  One of the USB cards have my bank of 5 USB connected CD/DVD burners that I use for Audio CD burning production.  The other one only has two devices that must have USB 2.0 ports as there are only USB 3.0 and 3.1 ports on my motherboard rear I/O Panel.
 
 
 

I see, you claiming 2x usb cards?...why 2?...Hubs exist...eh?
 
And the manual, should expose any shared slots with devices listed...Should I say if it is shown as listed in bios...You cannot move those from the slot assign, but you might be able to disable the device that is assigned to the slot, that is on the main board as a device.
 
 
 
Now In Bios do you have a listing for, PNP OS enabled?...That would be where you disable Win control over the Bios, I imagine, if you have the feature.
 
Problem is perhaps you are using too many cards...and things on the main board...you need to recoup, rethink, and get some hubs...and remove a card here...And read the manual for shared slots with onboard devices...to get the right slots assigned that share none or one thing you can disable...and assign it...in the windows system info/ Device manager to check the irq states.
 
In Xp you can then make a bootable configuration (say you want just your audio working) in device manager..disable nic, hdmi, and other things you left on in bios...usb?...I believe even that can be disabled in device manager....So depending on your needs for X...save as a bootable config name.
 
You can make many different configs bootable...so depending on what you need to do...with whatever devices you need working, can be setup to the way you want it, with what is only needed for that processing.
 
Say you only need internet...make a bootable config with nic and audio, with usb disabled....and boot to that named config.
 
If you need usb and audio...make the config no internet, and boot to that config.
 
If you only want one boot config...turn off (disable redundant devices in device manager).
 
So, I would reduce usb cards that are doubled up on slots for no reason, when a 7 port hub can address your needs on one card..or no cards....right from the MB usb ports, frees up two slots!...usb a,b,c...the only thing different usb ports offer is speed....So perhaps a give and rob from one to get the other...
 
 
Sorry, I have not done any of the above for some time...and I had to google how to do...and so I did follow that path.
 
I found, older MB's, got issues with more than two cards put in...one video, if so, and one other, put in a slot that is best suited for it's proper functioning for, should work..but three or more, always gets the sharing happening...Manuals must be read for slot assigned irq's, and in understanding these things...(keep it as simple a setup as possible)...there are cards that have both firewire 400/800 and usb now..so one card does double duties...and that is more so to find more alternate solutions...to how you got it now?...Might be sought to do some rethinking it out, your setup and card deployment...simple setups for one or two slotted card  devices, works better with MS windows...when put in properly and assigned proper...
 
But it ain't perfect ever!....Just to say...I've been there done that!...and still got one machine working with Xg midi daughterboard on isa audio card on XP..that way...still crashes, clicks pops and gets muddled up.
 
My solution was to get off the usb, and firewire band wagon...as it did not solve my issues with MS OSes, even trying out the new thunderbolt 1 ,2, and now 3...got issues with Windows oses..and usb not working proper in win 10 and wireless keyboards and mice.
So...Best of luck ....lol
 
Cheers.
 
 

 
https://www.microsoft.com..._dev_mgr.mspx?mfr=true
 
https://docs.microsoft.com/en-us/windows-hardware/drivers/install/device-manager-details-tab