Installing/Upgrading OSX

Install Mac OS X 10.6.* on its own disk partition, while preserving your current unmodified 10.5.* partition as a fallback.  

This is for systems running the Gigabyte EP45UD3P only, although it might work with other Gigabyte motherboards.  

Revision History: 
Now covers OSX 10.6.4
Now covers OSX 10.6.3
Questions/Comments are welcome.  

Summary of installation 
  • Use 10.5 Disk Utility to restore 10.6.0 and Chameleon to USB thumbdrive
  • Use USB thumbdrive to install 10.6.0 and Chameleon to new disk partition
  • Use Apple Software Update to upgrade 10.6.0 disk partition to 10.6.* 
  • Use Migration Assistant to import apps and data from 10.5 to 10.6.*
We used Lifehacker's snow-leopard-start-to-finish method.  Compared to upgrading-in-place, this method safely preserves a parallel 10.5.* instance.  In this guide, we use Chameleon to multi-boot (e.g. Linux, OSX 10.5, OSX 10.6, Windows).  We also review data migration and hardware redundancy.  We describe only our own experience with this hardware environment:

Hardware and BIOS
Mobo: Gigabyte GA-EP45-UD3P F5
  CPU: Intel Q6600 @ 2.4GHz x 4 (not overclocked)
 RAM: 6Gb (DDR2 SDRAM 800 MHz 2Gb x 3 pieces)
 GPU: NVIDIA GeForce 9500 GT in PCIe slot; 512Mb
  USB: Kensington DataTraveller 8Gb
 HDD: ST31000528AS, Rev CC34, Serial 5VP01BK0

BIOS: Award Modular BIOS v6.00PG 2008, PnP 1.0a, DMI 2.0, SM BIOS 2.4, ACPI 1.0b

  • USB thumbdrive (or memstick) 8Gb or bigger
  • New disk partition that will hold your new 10.6 installation
  • A purchased retail copy of Snow Leopard DVD (.dmg)
  • The EP45UD3P Snow Leopard install package
  • Access to existing OSX 10.5 system
  • 2 to 3 hours 
Step 1: Prepare existing OSX 10.5 disk partition
  • (optional) Update from 10.5.* to 10.5.8 using Apple Software Update
  • (for the paranoid) Save a list of your installed apps (ls /Applications/ > ~/apps.txt)
  • (for the paranoid) Save a list of your Firefox plugins & add-ons
  • clean up and prepare
  • TimeMachine to backup latest data
Step 2: Prepare host
  • Unplug all unneeded cards, USB devices, IDE-to-SATA interfaces, FAT-32 disks
  • Unplug all unneeded disks (to avoid installing to wrong disk!)
  • See more supported hardware for ideas on future choices
  • BIOS: disable over-clocking and higher DRAM voltages
  • BIOS: boot from USB memstick (vs. disk)
(Use OSX 
Disk Utility for next s
Step 3: Prepare bootable USB memstick
Step 4: Install 10.6 to new target disk
  1. Boot from USB memstick (Chameleon boot loader)
  2. Prepare new target disk: 
    • Partition Map Type: GPT (GUID Partition Table)
    • File System: Journaled HFS+
  1. Install 10.6 from USB memstick to new disk partition
  2. install EP45UD3P Snow Leopard install package v3
  3. Reboot and set BIOS to boot from new disk (now with Chameleon boot loader).
  4. install 10.6.4 combo update from Apple
  5. Reboot and Apple Software Update to upgrade 10.6.2 to 10.6.3+
  6. Reboot to verify new disk partition can boot latest Snow Leopard
  7. Shutdown and reinstall cards, USB devices, FAT-32 disks, IDE-to-SATA interfaces
  8. pple Software Update (for any device drivers of your reinstalled hardware)
  9. Get ready to migrate all your data/apps from 10.5.x (see below)
Tip: Donations help with future guides.
System Profiler reports:
Hardware Overview:
  Model Name:            Mac Pro
  Model Identifier:      MacPro3,1
  Processor Speed:       2.43 GHz
  Number Of Processors:  1
  Total Number Of Cores: 4
  L2 Cache:              8 MB
  Memory:                6 GB
  Bus Speed:             1.07 GHz
  Boot ROM Version:      MP31.00C1.B00
  SMC Version (system):  1.13f3
  Serial Number (system):W87234JHYA4

NVIDIA Graphics Engine:
  Chipset Model:         NVIDIA Graphics Engine
  Type:                  GPU
  Bus:                   PCIe
  Slot:                  PCI
  PCIe Lane Width:       x16
  VRAM (Total):          512 MB
  Vendor:                NVIDIA (0x10de)
  Device ID:             0x0640
  Revision ID:           0x00a1
  ROM Revision:          NVIDIA Graphics Engine DSDT
  Resolution:            1680 x 1050 @ 60 Hz
  Pixel Depth:           32-Bit Color (ARGB8888)
  Main Display:          Yes
  Mirror:                Off
  Online:                Yes
  Rotation:              Supported
Display Connector:
  Status:                No Display Connected

Migration (from 10.5 to 10.6.*)
To avoid reinstalling non-vanilla applications (with all their associated settings/cookies/etc), we used Migration Assistant to import from a 10.5 Time Machine backup all except "Machine settings".  This brought over everything except the eSATA host card driver from Silicon Image.

Post-migration, all system components are working well, including sound and video.  The key is using a supported motherboard and video card, as referenced at OSX86 Hardware Compatibility List for 10.6.

Pros/Cons of other guides:
  • pro: Clear and easy, with video
  • pro: Chameleon installed into hidden EFI partition to enable updates from Apple
  • con: Doesn't discuss Chameleon details (e.g. custom kexts)
Dual boot using custom Kexts by MacNutty
  • pro: Comprehensive and clear
  • pro: Discusses custom kexts
  • con: Doesn't seem to cover installation into hidden EFI partition for future updates from Apple
Further investigation
Good luck!
Referenced from OSX86 Hardware Compatibility List 10.6, under motherboard vendor Gigabyte GA-EP45-UD3P.