Why does my 2006 Mac Pro 1,1 crash on startup?

Question

Hi, folks--
My 2006 Mac Pro is regularly crashing on startup with a kernel panic. It will chime on startup and usually show me the Apple startup screen with the spinning wheel-- but after that, I get the multi-language "You need to restart your computer. Hold down the Power button until it turns off, then press the Power button again" message. Sometimes it doesn't even get there-- the spinning wheel just freezes, and stays frozen. Every once in a while, the Mac will start up, but the mouse will be so unresponsive that it takes me several minutes to mouse over to Restart so I can try again. (I've checked the mouse on another computer and it works fine.)
Additional info:
• I have one SSD startup disk with Lion, and two HDD startup disks with Snow Leopard. Starting up with any of these three disks results in the problems described above. This suggests to me that it's a hardware problem, rather than a problem with a specific startup disk.
• I tried starting up from my Snow Leopard Install disk. It was able to start up successfully. All the data on my hard drives seemed to be intact, including Lion Install, so I tried re-installing Lion on my SSD. It showed the blue progress bar for a minute. Then it said it would restart my computer in 30 seconds-- at which point, I once again got the multi-language "You need to restart your computer. Hold down the Power button ETC" crash. If even the install disk is crashing, this again suggests a hardware problem.
• I set the Mac Pro to target mode, and used it as a startup disk for my wife's Macbook. It functioned just fine and there were no crashes. Again, confirmation that it is a hardware problem with my Mac Pro.
• I have zapped the PRAM. I have also run Disk Utility, repaired permissions, and verified the disk. This did not fix the issue. (Not surprising if it is a hardware problem.)
• HOWEVER:  I put in the install disk that came with the computer originally and was able to complete the Hardware Test. I chose the most thorough option. It did not find any problems.
• This started happening three days ago. I'm not aware of any recent changes to the system that could have caused this. The most recent change I made was installing a Radeon HD 5770  graphics card and an SSD drive, more than a month ago. There was no sign of trouble after I installed either of them (except for some problems putting the Mac Pro to sleep, which is apparently a known issue with the Radeon 5770 in this model Mac Pro).
• Weirdly, after I fiddle with the Mac Pro for an hour or so (run diagnostics, reboot it repeatedly, etc) it seems to start working. If there is indeed a hardware problem, then perhaps something works better when it's warmed up.
Is there anything you'd suggest I try? Or am I stuck lugging it to the Genius Bar? I don't have a car, so this is a bit of a pain…
Thanks in advance for any help you can give!

Answer 1

Thanks, The Hatter. I'm working through all the links you've provided and see if I can narrow down the problem.
And, Grant, thanks as well-- I really appreciate the specific information. You've enabled me to track down the panic log -- but they are indeed baffling. I'm pasting one below, in case somebody wiser than I can interpret it for me.
Wed Mar  6 11:25:26 2013
panic(cpu 2 caller 0x2ceabf): Kernel trap at 0x00baf978, type 14=page fault, registers:
CR0: 0x8001003b, CR2: 0x8da19000, CR3: 0x00100000, CR4: 0x00000660
EAX: 0x7db19000, EBX: 0x07eb6004, ECX: 0x0ff00000, EDX: 0x0ff00000
CR2: 0x8da19000, EBP: 0x4469bc38, ESI: 0x0ff00000, EDI: 0x08feab04
EFL: 0x00010206, EIP: 0x00baf978, CS:  0x00000008, DS:  0x00000010
Error code: 0x00000000
Backtrace (CPU 2), Frame : Return Address (4 potential args on stack)
0x4469ba98 : 0x2203de (0x6b08cc 0x4469bab8 0x229fb0 0x0)
0x4469bac8 : 0x2ceabf (0x6bd9e0 0xbaf978 0xe 0x6bd989)
0x4469bb78 : 0x2e5564 (0x4469bba0 0x4469bb88 0x4469bb98 0x22cbbb)
0x4469bb98 : 0xbaf978 (0xe 0x44690048 0xff1b0010 0x10)
0x4469bc38 : 0x1547167 (0x8ad2c04 0x7eb6004 0xff00000 0x7eb6004)
0x4469bc58 : 0x153e35c (0x7eb6004 0x8feab04 0x0 0xff00000)
0x4469bc88 : 0xcb6c56 (0x7eb6004 0x9465004 0x4469bca0 0x0)
0x4469bd38 : 0xd27c8a (0x7eb6004 0x9465004 0x8971c14 0xff)
0x4469bdc8 : 0xd2933e (0x7eb6004 0x8a97c04 0x0 0x0)
0x4469be28 : 0xd2b46a (0x7eb6004 0x8a97c04 0x8 0x2)
0x4469be58 : 0x1562269 (0x7eb6004 0x8a97c04 0x0 0x0)
0x4469be88 : 0xd2b589 (0x7eb6004 0x8a97c04 0x0 0x0)
0x4469bed8 : 0xb9eb05 (0x7eb6004 0x0 0x0 0x0)
0x4469bf68 : 0xb5362c (0x7eb6004 0x1 0x7c637f0 0x7c63be8)
0x4469bf98 : 0x23e4ae (0x8af4400 0x7eb6004 0xfa6d03 0x7eb4028)
0x4469bfc8 : 0x2c7d0c (0x84ad60 0x0 0x10 0x92f8410)
      Kernel Extensions in backtrace:
         com.apple.NVDAResman.G7xxx(7.0.4)[6581C9F3-3221-4530-BEB4-627CB8D602AE]@0xb4c00 0->0xe41fff
            dependency: com.apple.iokit.IOPCIFamily(2.7)[8087C029-833E-4B62-A8C3-2B074B4C55F7]@0xade000
            dependency: com.apple.iokit.IONDRVSupport(2.3.4)[393829BA-614C-4ED7-B4AD-CE577A41C683]@0xb3 b000
            dependency: com.apple.iokit.IOGraphicsFamily(2.3.4)[EE3F8FBE-3457-4F0E-A3A3-B9B1A44DCF6B]@0 xb07000
         com.apple.nvidia.nv40hal.G7xxx(7.0.4)[C61073DF-524F-472B-A19F-3B80B884F6C5]@0x1 4b2000->0x15bdfff
            dependency: com.apple.NVDAResman.G7xxx(7.0.4)[6581C9F3-3221-4530-BEB4-627CB8D602AE]@0xb4c00 0
BSD process name corresponding to current thread: kernel_task
Mac OS version:
11G63
Kernel version:
Darwin Kernel Version 11.4.2: Thu Aug 23 16:26:45 PDT 2012; root:xnu-1699.32.7~1/RELEASE_I386
Kernel UUID: 859B45FB-14BB-35ED-B823-08393C63E13B
System model name: MacPro1,1 (Mac-F4208DC8)
System uptime in nanoseconds: 37415286581
last loaded kext at 10244857365: com.apple.driver.AppleHWSensor          1.9.5d0 (addr 0x3125000, size 28672)
loaded kexts:
com.microsoft.driver.MicrosoftMouseUSB          8.2
com.microsoft.driver.MicrosoftMouse          8.2
com.microsoft.driver.MicrosoftKeyboardUSB          6.2.2
com.microsoft.driver.MicrosoftKeyboard          6.2.2
com.apple.driver.AppleHWSensor          1.9.5d0
com.apple.filesystems.autofs          3.0
com.apple.driver.AppleHDAHardwareConfigDriver          2.2.5a5
com.apple.driver.AudioAUUC          1.59
com.apple.driver.AppleHDA          2.2.5a5
com.apple.driver.AppleTyMCEDriver          1.0.2d2
com.apple.driver.AppleUpstreamUserClient          3.5.9
com.apple.driver.AppleMCCSControl          1.0.33
com.apple.kext.ATIFramebuffer          7.3.2
com.apple.iokit.IOUserEthernet          1.0.0d1
com.apple.GeForce          7.3.2
com.apple.iokit.IOBluetoothSerialManager          4.0.8f17
com.apple.GeForce7xxx          7.0.4
com.apple.Dont_Steal_Mac_OS_X          7.0.0
com.apple.driver.AudioIPCDriver          1.2.3
com.apple.driver.AppleMCEDriver          1.1.9
com.apple.ATIRadeonX3000          7.3.2
com.apple.driver.ACPI_SMC_PlatformPlugin          5.0.0d8
com.apple.driver.ApplePolicyControl          3.1.33
com.apple.driver.AppleLPC          1.6.0
com.apple.driver.CSRUSBBluetoothHCIController          4.0.8f17
com.apple.driver.CSRHIDTransitionDriver          4.0.8f17
com.apple.iokit.SCSITaskUserClient          3.2.1
com.apple.driver.XsanFilter          404
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless          1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib          1.0.0d1
com.apple.BootCache          33
com.apple.iokit.IOAHCIBlockStorage          2.1.0
com.apple.driver.AppleFWOHCI          4.9.0
com.apple.driver.AirPortBrcm43224          501.36.15
com.apple.driver.AppleIntelPIIXATA          2.5.1
com.apple.driver.AppleAHCIPort          2.3.1
com.apple.driver.AppleUSBHub          5.1.0
com.apple.driver.AppleIntel8254XEthernet          2.1.3b1
com.apple.driver.AppleEFINVRAM          1.6.1
com.apple.driver.AppleUSBEHCI          5.1.0
com.apple.driver.AppleUSBUHCI          5.1.0
com.apple.driver.AppleACPIButtons          1.5
com.apple.driver.AppleRTC          1.5
com.apple.driver.AppleHPET          1.7
com.apple.driver.AppleSMBIOS          1.9
com.apple.driver.AppleACPIEC          1.5
com.apple.driver.AppleAPIC          1.6
com.apple.driver.AppleIntelCPUPowerManagementClient          195.0.0
com.apple.nke.applicationfirewall          3.2.30
com.apple.security.quarantine          1.4
com.apple.security.TMSafetyNet          8
com.apple.driver.AppleIntelCPUPowerManagement          195.0.0
com.apple.kext.triggers          1.0
com.apple.driver.DspFuncLib          2.2.5a5
com.apple.driver.AppleSMBusController          1.0.10d0
com.apple.iokit.IOSurface          80.0.2
com.apple.iokit.IOSerialFamily          10.0.5
com.apple.iokit.IOFireWireIP          2.2.5
com.apple.iokit.IOAudioFamily          1.8.6fc18
com.apple.kext.OSvKernDSPLib          1.3
com.apple.driver.AppleSMC          3.1.3d10
com.apple.driver.IOPlatformPluginLegacy          5.0.0d8
com.apple.nvidia.nv50hal          7.3.2
com.apple.driver.AppleGraphicsControl          3.1.33
com.apple.driver.AppleHDAController          2.2.5a5
com.apple.iokit.IOHDAFamily          2.2.5a5
com.apple.driver.AppleSMBusPCI          1.0.10d0
com.apple.nvidia.nvGK100hal          7.3.2
com.apple.driver.IOPlatformPluginFamily          5.1.1d6
com.apple.kext.ATI5000Controller          7.3.2
com.apple.kext.ATISupport          7.3.2
com.apple.nvidia.nvGF100hal          7.3.2
com.apple.NVDAResman          7.3.2
com.apple.nvidia.nv40hal.G7xxx          7.0.4
com.apple.NVDAResman.G7xxx          7.0.4
com.apple.iokit.IONDRVSupport          2.3.4
com.apple.iokit.IOGraphicsFamily          2.3.4
com.apple.driver.AppleUSBBluetoothHCIController          4.0.8f17
com.apple.iokit.IOBluetoothFamily          4.0.8f17
com.apple.driver.AppleFileSystemDriver          13
com.apple.iokit.IOUSBHIDDriver          5.0.0
com.apple.driver.AppleUSBComposite          5.0.0
com.apple.iokit.IOSCSIMultimediaCommandsDevice          3.2.1
com.apple.iokit.IOBDStorageFamily          1.7
com.apple.iokit.IODVDStorageFamily          1.7.1
com.apple.iokit.IOCDStorageFamily          1.7.1
com.apple.iokit.IOATAPIProtocolTransport          3.0.0
com.apple.iokit.IOSCSIArchitectureModelFamily          3.2.1
com.apple.iokit.IOFireWireFamily          4.4.8
com.apple.iokit.IO80211Family          420.3
com.apple.iokit.IOATAFamily          2.5.1
com.apple.iokit.IOAHCIFamily          2.0.8
com.apple.iokit.IONetworkingFamily          2.1
com.apple.iokit.IOUSBUserClient          5.0.0
com.apple.iokit.IOUSBFamily          5.1.0
com.apple.driver.AppleEFIRuntime          1.6.1
com.apple.iokit.IOHIDFamily          1.7.1
com.apple.iokit.IOSMBusFamily          1.1
com.apple.security.sandbox          177.8
com.apple.kext.AppleMatch          1.0.0d1
com.apple.driver.DiskImages          331.7
com.apple.iokit.IOStorageFamily          1.7.2
com.apple.driver.AppleKeyStore          28.18
com.apple.driver.AppleACPIPlatform          1.5
com.apple.iokit.IOPCIFamily          2.7
com.apple.iokit.IOACPIFamily          1.4