Just got done transplanting the original Quad 500mhz R14000 motherboard in my O300 in favor of a Quad 600mhz R14000A motherboard.
Pretty painless transplant, had to go out to Home Depot for an additional Torx bit for the Numalink Torx screw on the back, but other than that you might need some needle-nose pliers to get the ATXish power connections unlatched too.
Code:
4 600 MHZ IP35 Processors
CPU: MIPS R14000 Processor Chip Revision: 2.4
FPU: MIPS R14010 Floating Point Chip Revision: 2.4
CPU 0 at Module 001c16/Slot 0/Slice A: 600 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.4. Scache: Size 4 MB Speed 300 Mhz Tap 0x1a
CPU 1 at Module 001c16/Slot 0/Slice B: 600 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.4. Scache: Size 4 MB Speed 300 Mhz Tap 0x1a
CPU 2 at Module 001c16/Slot 0/Slice C: 600 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.4. Scache: Size 4 MB Speed 300 Mhz Tap 0x1a
CPU 3 at Module 001c16/Slot 0/Slice D: 600 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.4. Scache: Size 4 MB Speed 300 Mhz Tap 0x1a
Main memory size: 2048 Mbytes
Instruction cache size: 32 Kbytes
Data cache size: 32 Kbytes
Secondary unified instruction/data cache size: 4 Mbytes
Memory at Module 001c16/Slot 0: 2048 MB (enabled)
Bank 0 contains 1024 MB (Premium) DIMMS (enabled)
Bank 1 contains 1024 MB (Premium) DIMMS (enabled)
Integral SCSI controller 0: Version QL12160, low voltage differential
Disk drive: unit 1 on SCSI controller 0 (unit 1)
Disk drive: unit 2 on SCSI controller 0 (unit 2)
Integral SCSI controller 1: Version QL12160, low voltage differential
IOC3/IOC4 serial port: tty3
IOC3/IOC4 serial port: tty4
Integral Fast Ethernet: ef0, version 1, module 001c16, pci 4
PCI Adapter ID (vendor 0x1077, device 0x1216) PCI slot 1
PCI Adapter ID (vendor 0x10a9, device 0x0003) PCI slot 4
PCI Adapter ID (vendor 0x11c1, device 0x5802) PCI slot 5
IOC3/IOC4 external interrupts: 1
HUB in Module 001c16/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)
IP35prom in Module 001c16/Slot n0: Revision 6.124
USB controller: type OHCI
Pictures to come in the morning!
_________________

33mhz R3k/48mb/XS24

150mhz R4400/256mb/XL24

600mhz R14kA/2gb/V10

8x1.4ghz Itanium 2/8GB

32x600mhz R14kA/24GB

4x700mhz R16k/8GB/V12/DCD/SAS/FC/DM5

2x700mhz R16k/4GB