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PC workstation with full PCI bus numbering (ie. 256)?

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Hi there!


I have a problem with DELL Optiplex 7010 and two PXIe chassises connected to it like this:


PC PCie8372      port 1 ->              3 meter cable ->              PXIe-8370 ->      Chassis 1 PXIe-1065

                               port 2  ->             3 meter cable ->              PXIe-8370 ->      Chassis 2 PXIe-1075


Problem is that in Windows event log nipxirfk service complains that  "PCI Host Bridge: Maximum bus number limit reached before enumerating all devices,  status = -313563"


When I have tried different things to solve the problem like removing PCI bus GPIB card and switching PXIe chassises to different ports on PCIe card, half of the PC USB ports have stopped working and when I have changed something else the other half stops working 🙂


PC has limited bus numbers availability:


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===NI Resource Root Bus Detection Utility===
This utility determines the number of PCI/PCI Express root bus
devices on your system and whether there are any bus number
range limitations that could cause hardware problems.

Single root bus detected.
Your system has a single PCI root bus.
Root bus has a limited range.
Your system BIOS has a set limit on the range of bus numbers
you can assign to your PCI tree. In Windows XP, this limit is ignored
and has no impact. In Windows Vista and later, the limit is strictly
enforced and cannot be exceeded. As such, the amount of MXI-Express
hardware you can attach is limited. Refer to the bus number range
below for your system's limitations.


----- Root Bus: ACPI\PNP0A08\0 -----
Bus Number Range: [0, 3e]
Status: Device is running

This utility ran with no errors.


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So I take there just isn't enough PCI bus numbers available on this PC to allocate enough resources to all connected devices. There is nothing left on PC PCI bus that I could remove or nothing that I could disable from BIO, in fact I have to put back PCI GPIB card and that will eat resources further. Both PXIe chassises are about half full of instruments and I need to add few more card to one of them. PC BIOS is up to date. I have been sorting out details with NI support already but they do not have solution yet. Our lab has two older HP/DELL workstations (no longer available) with limited PCI bus numbering that work with the same two chassises just fine. I think this problem is PC BIOS related and my computer is just on the limit of not working.


Basically I need to know some current PC workstation that people have used succesfully for controlling atleast two (2) PXIe chassises. If you could check you workstations PCI bus numbering capability with this NI tool:




And posting the results here I would be very grateful.

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Message 1 of 5
Accepted by topic author Jan_Nousiainen



Some Dell BIOSes have an option for setting the max number of PCIe buses.  A lower number allows more usable memory in a 32-bit OS.  I've seen it in some of the Precision desktops like the T3600.  On those machines you go to the BIOS and go to System Configurationoption» PCI Bus Configuration, then change the value to something higher (like 256).  Can you check for that option?


- Robert

Message 2 of 5

Thanks for your reply 🙂


I did check the available BIOS settings when I started troubleshooting and there is no settings for PCI bus configuration and I just checked the manual and there was no mention either. So I guess there is no settins for it.


It seems that this Optiplex series is kind of general office work PC while Precisions series are more serious workstations and propably because of that offer more settings in BIOS. I have to check some current Precision model manuals to see if there is mention about PCI bus configuration.

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Message 3 of 5

Checked Dell Precision T3610 & T5610 & T7610 User Manuals (models currently available) and found the BIOS setting you mentioned (look at the attachment). You can choose either 64, 128 or 256 PCI buses, yay!


Tried looking same info on Lenovo Thinkstation manuals but did not find anything.


So now I know that atleast those workstations should solve the problem and this case is solved for me I hope, thank you for the tip 🙂

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Message 4 of 5

Recent UEFI workstations (= all new workstations, it seems?) don't offer this option anymore.

would anyone have any advice on how to keep using a PXI-1044 on a new workstation?

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