ok im looking at the board for the xw6400 now, it has 4 dimm slots, 4 pciexpress slots 2 x16 and 2x8 and 2 32bit pci normal slots

Gemini said
You’ve found the exact motherboard layout for the HP xw6400, and your observation is spot on. It is a compact, highly efficient version of that 5000X chipset architecture.
Since this board is effectively the "twin" of the Mac Pro 1,1/2,1 logic board, your confidence in its Tiger (10.4.11) support should be high. However, because it’s a "miniaturized" workstation, we need to look closely at how you'll fit all your gear into those specific slots.
The Slot Strategy (HP xw6400 Board)
With only six slots total, every inch of that board is prime real estate. Here is how I would recommend mapping your hardware to ensure zero bottlenecks:
PCI Express x16 (Slot 1): GeForce 7900 GTX.
Why: This gives your GPU the full direct bandwidth it needs for Tiger’s "Quartz Extreme" and Windows XP gaming/GUI acceleration.
PCI Express x8 (Slot 2): SiI3132 (SATA II) or MOTU PCIe-424.
Note: On this board, the x8 slots are usually "open-ended" or can handle x1/x4 cards easily. If you have the PCIe version of the MOTU card, put it here to keep your audio data on the faster, modern bus.
PCI Express x8 (Slot 3): Your remaining PCIe card.
PCI Express x16 (Slot 4): Open for future use (or a second GPU/high-speed storage).
PCI 32-bit (Slot 5): M-Audio Delta 1010LT.
Why: This is a legacy card that doesn't need much bandwidth. It will be perfectly happy here.
PCI 32-bit (Slot 6): M-Audio Delta 410 or a TI Firewire Card.
Critical: Check if your specific xw6400 board has the TI Firewire chip integrated (look for a small chip near the Firewire port labeled "TI"). If it does, you save this slot!
Why you can be sure about Tiger (10.4.11)
The Intel 5000X chipset is the "holy grail" for Intel Tiger builds because:
The Bootloader: Tiger expects a specific communication method between the CPU and the chipset (the 1333 MHz FSB). The xw6400 provides this natively.
The Memory: Tiger is very particular about FB-DIMM architecture on multi-socket systems. Because the xw6400 uses the same memory controller as the Mac Pro 2,1, you won't get the "Stuck at gray screen" errors that often happen on newer chipsets (like the 5400).
The CPU: If you drop two Xeon E5345 or X5355 processors in there, Tiger sees them as "Genuine Intel" Mac Pro CPUs, which helps with native speedstep and power management.
One Small Caveat: The 4 DIMM Limit
As you noticed, the xw6400 has 4 DIMM slots, whereas the larger xw8400 has 8.
The Impact: This limits you to 16GB of RAM (4×4GB).
The Reality: For a 2007-era studio running Logic 7 or Pro Tools 7, 16GB is actually massive. In fact, Tiger (32-bit) can only effectively use about 3.5GB per application anyway. You will have more than enough overhead for your multi-boot timeline.
Final Check for the "OldSchoolDAW" Community
If you're documenting this for the forum, the xw6400 is the "Sleeper" choice. It’s smaller, uses less power, and is easier to find in the Ontario used market than the massive xw8400, but it delivers the exact same "Mac Pro 2,1" soul.
Since you are looking at the board now, do you have the PCIe version of the MOTU 424, or are you still holding onto a PCI-X version? (If it's PCI-X, we might need to pivot back to a board with those long slots!)
You said
i was hoping it had pci-x but having 3 exta pci-e slots is almost superior to pci-x slots if theres now bandwidth sharing?
Gemini said
You’re touching on exactly why the HP xw6400 architecture is so highly regarded. By moving away from the "shared" nature of legacy PCI and PCI-X, this board offers a much more modern and stable environment for a high-end DAW.
The "No Bandwidth Sharing" Advantage
On older PCI and PCI-X boards, all those slots were often connected to the same "bus." If your storage card was busy writing data, your audio card had to wait its turn, leading to the pops and clicks we've discussed.
The PCI Express (PCIe) slots on the xw6400 are point-to-point connections. This means:
Dedicated Lanes: Your GeForce 7900 GTX in the x16 slot doesn't "see" the data from your MOTU PCIe-424 in the x8 slot.
Full Duplex: PCIe can send and receive data simultaneously, which is a massive upgrade for audio interfaces that need to record and play back dozens of tracks at once.
Lower Latency: Because the CPU doesn't have to manage a "traffic jam" on a shared bus, your DPC latency stays incredibly low, which is the key to running Tiger 10.4.11 or Windows XP with a tiny buffer size.
Optimizing Your Specific Slots
Since you have four PCIe slots and two 32-bit PCI slots, you can achieve a "Best of Both Worlds" setup:
The Powerhouse PCIe Section: Use the x8 slots for your MOTU PCIe-424 and your SiI3132 SATA card. These will have their own dedicated "highways" to the Intel 5000X chipset.
The Legacy PCI Section: Use the two standard PCI slots for your M-Audio Delta 1010LT and Delta 410. Since these cards don't require massive bandwidth, they won't feel restricted by the 32-bit bus.
Why this is "Superior" for Your Project
For your OldSchoolDAW preservation project, this layout is actually better than having PCI-X. Most PCI-X cards were long, hot, and required specific voltages. By using the PCIe versions of your storage and audio controllers, you get:
Lower Heat: PCIe cards from this era generally run cooler than their bulky PCI-X ancestors.
Better Part Availability: Finding a replacement SiI3132 is often easier and cheaper than hunting down a server-grade SiI3124.
Future-Proofing: If you ever decide to boot a slightly newer OS like Lion (10.7.5), these PCIe cards have much better driver longevity.
A Quick Check for Your Inventory
Since this board relies on PCIe for its high-speed expansion, double-check that your MOTU 424 is the PCIe version (it will have a very short connector). If you have the long PCIX-424 card, it unfortunately won't fit in these slots.
Would you like me to find the specific Silicon Image 3132 PCIe or MOTU PCIe-424 cards to make sure you have the right versions for this xw6400 board?