Welcome to the last PC buyer's guide for 2009 - today we are looking at the last few pieces of the hardware puzzle, specifically hard drives, optical drives and memory.

Much like any other components we have looked at, you will want to decide what your PC will be used for before settling on any particular product here. For instance, components with low noise and heat output plus low power requirements will appeal to people building Home Theatre PCs, whereas gaming enthusiasts usually want maximum punch without worrying about most of those things, and those of you building a basic workhorse box probably just want something cheap and reliable that won't need to be replaced in 12 months.

Hard Drives

The first choice you're likely to come up against when looking at hard drives is whether to go HDD or SSD.

HDDs (Hard Disk Drives, aka "mechanical" drives) are the type of storage drive you're probably familiar with - they are the 3.5" little grey boxes inside your PC that make an incessant clicking noise when you are doing stuff on your computer (although modern drives are pretty quiet). They are cheap and cheerful, offering capacities up to 2TB (2,000GB) for as little as $329 NZD (roughly $0.16 per gigabyte). They are also the slowest part of modern computers.

This is where SSDs (Solid State Drives) swoop in to save the day. As the name implies there are no moving parts in an SSD, so data can be accessed virtually instantaneously, and their parallel nature means that read and write speeds are off the charts compared to old HDDs. Unfortunately they can also be prohibitively expensive. The popular 160GB Intel X25-M will set you back $849 (a whopping $5.30 per gigabyte).

A good compromise is to go with a small-ish SSD to house the operating system and your most commonly used applications and games, plus a larger HDD to store all your bulky files, videos, music etc. Decent 64GB SSDs can be had for under $300 which may still seem expensive, but a decent PC these days costs upwards of $2,000 so it's not a huge ask to ensure that the biggest performance bottleneck in your system is removed.

Any type of system, be it a HTPC, gaming beast or 'net browser, will benefit from an SSD as the main drive, so unless you're budget constrained or really, really don't give a hoot about performance then I'd recommend going for one. Just make sure that you look for drives with Intel or Indilinx controllers (this is a vital indicator of the drive's performance). Samsung controllers are also acceptable, whilst JMicron should be avoided. Any SSD, no matter what brand or controller, will have low power consumption, negligible heat and absolutely no noise output.

Mechanical HDDs come in two main flavours - performance and economy (although the actual marketing names vary). Performance drives have faster read/write speeds at the expense of noise and price. Economy drives have lower noise/heat output, lower power requirements and a lower price tag at the expense of performance (generally because the internal disks spin slower). Performance drives are suitable as main boot drives whereas economy drives should be reserved for backup, storage, or HTPC drives.

Here are a selection of drives across the board that I can recommend...

SSD:
Kingston 64GB SSDNow V-Series SNV125-S2BD $235
Corsair 64GB X64 $409
Intel 160GB X25-M G2 $849

Performance HDD:
Western Digital 640GB Caviar Blue $109
Samsung 1TB Spinpoint F3 $145

Economy HDD:
Western Digital 1TB Caviar Green $136
Western Digital 2TB Caviar Green $329

Next page: Optical Drives and Memory.