Dual Core vs P4 1633

journey

Nope, disk limited.

Nope, disk limited again.

Nope, requires virtually no processing power.

Only in certain cases that a home user will never run into (eg. when the CPU is controlling say a 10 disk RAID5 setup).

If you feel any speedup in what you listed above, then it's in your head. Different computing tasks have different limiting factors, and in general the slowest piece of hardware (and hence most common limiting factor) is your hard disk. Both disk defragmentation and virus checking are limited by your HDD's read speed which is much less than how fast your processor can process files (by process I mean, check for fragmentation or scan for viruses). Moving files around on a single drive is typically limited by the drive's write speed. In the case of multiple drives (eg. in a RAID array), the controller of the array (which could be a CPU) can be the limiting factor, but that's only in the extreme case (eg. huge databases). External drives connected on serial connections like USB or Firewire are also effected by CPU, but the amount of processing power necessary is minimal (like in playing MP3's).

CPU limited tasks include compiling, solving math functions, transcoding video-encoding audio (often disk limited, but if you're writing to a fast disk, eg. a RAM disk, your limit is the CPU), hashing pbuttwords, rendering engines (can be RAM limited), etc.