The compilation of gcc46 requires too much time for me. 

Code:
> dmesg | grep -i cpu
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 5200+ (2705.78-MHz K8-class CPU)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0
powernow0: <PowerNow! K8> on cpu0
powernow1: <PowerNow! K8> on cpu1
SMP: AP CPU #1 Launched!
> cd /usr/ports/math/octave
> make all-depends-list | grep -i gcc
/usr/ports/lang/gcc46
cd /usr/ports/math/R
> make all-depends-list | grep -i gcc
/usr/ports/lang/gcc46
cd /usr/ports/math/py-scientific/
> make all-depends-list | grep -i gcc
/usr/ports/lang/gcc46