There's no right answer. PC-based servers are cheaper but purpose-built servers offer advantages in reliability and redundancy.

The following table shows my recommendations:-

Number of Users

PC-Based Server

Purpose-Built Server

These prices are for high-spec models that include SCSI RAID arrays and redundant power supplies

PC-Based Server

Purpose Built Server

There are no tricks (that I know about) to circumvent these limitations.

You can purchase an upgrade from SBS 2003 to Windows Server 2003 Standard Edition if you decide later that you made the wrong choice.

There is also a Premiun Edition of SBS 2003 that includes a Database server and a firewall.

More information about SBS 2003 here

The Outlook client can be installed on as many computers as you have Client Access Licences (CALs)

My Recommendation

If you think you might want a second Domain Controller for redundancy then a few £100s saved on the cost of software now, won't be worth the hassle later.

A company needs a connection to the Internet in order to send and receive emails - all other uses of the Internet are secondary

A good email system allows you to access company mail wherever you are. It should be designed so that if the main system fails emails are not lost but are stored on a backup system - perhaps a catch-all POP3 mailbox at an ISP.

Anti-virus scanning and spam filtering are also important.

Steps in the Cycle

Status

Cost

The never ending quest for more powerful, easier to use and cheaper computers continually drives the pace of hardware development.

Although a component may take 5 to 10 years to complete the Hardware Life Cycle, 3 months is enough for a component to move on a step and make the specification below become out-of-date.

Component

Recommended Item

UK Supplier
& Weblink

Cost
(excl. VAT)

Extras You Might Need

Component

Recommended Item

UK Supplier
& Weblink

Cost
(excl. VAT)

(24x10/100+2x10/100/1000)

£80.83

+ 25 CALs

Then try these alternative UK

mail-order computer companies:-

www.simply.co.uk

http://www.savastore.com/watford/

http://uk.insight.com/index.php?ref=

Traditional IDE hard drives were more correctly referred to as ATA but now, for clarity, should be called PATA drives (P for Parallel).

The fastest transfer rate that the PATA interface can achieve is 133mbps while current SATA drives operate at 150mbps with future standards promising transfer rates of 300mbps and 600mbps.

PATA drives are now obsolete because the standard won't be developed further and all innovation efforts will now focus on the SATA standard.

This seems unfair on the PATA standard when you realise that the actual physical hard drive mechanism behind all hard drives struggles to provide data faster than 60mbps - half the speed that PATA can handle. Comparing a current PATA and SATA drive will show a few percentage points of increased performance from the SATA drive due to burst mode transfers where data is taken from a drive's on-board cache.

For the last 15 years or so SCSI drives have been more expensive than IDE drives of the same capacity and currently cost around 4 times as more. This margin has to be mostly artificial so expect SATA drives to soon steal some of the market for SCSI drives.

Drive manufacturers have a lot of work ahead of them if they're to make use of the current and future SATA bandwidth. They might do this with faster rotational speeds or denser storage on the magnetic coating but it's going to take a revolution in the way hard drives work for them to supply data anywhere near 600mbps.

If you've now got PATA drives there's certainly no point in replacing them but I recommend all new server drive purchases should be SATA drives - unless you can afford SCSI.

I've also heard about a SATAPI standard for CD and DVD drives to connect to so that motherboards can be made without PATA channels.

SATA - Fast Facts

Only one drive per SATA channel so no more drive jumpers or master and slave drives.

SATA drives have a new power connector which is bigger than the data connector. As power supplies don't come with SATA power connectors yet, you need a Molex-to-SATA convertor.

The SATA standard was designed with hot-swapping in mind which can be seen in the power and data connectors.

Currently SATA drives require drivers to be loaded from a floppy when installing Windows - in a similar way to SCSI drives.

SATA drives use a different HAL to IDE drives so  upgrading from IDE for SATA isn't straightforward.

A SATA data cable can be up to 1 metre long which allows for external drives.

The 15mm wide SATA cable won't obstruct the internal flow of cooling air as much as the far wider PATA cable.

The Western Digital Raptor 36gb SATA drive for £62.12 is an example of a 10,000rpm drive, details here.

"...mine's on the RPM..."

The first Intel dual-core processors still have hyper-threading - see later in this section - which means a server with 2 CPU sockets fitted with 2 dual-core Pentiums will show 8 logical CPUs in Task Manager.

A dual-CPU server may continue to operate after one of the CPUs has failed - a sort of CPU RAID. This is unlikely to happen if both CPUs are on the same core.

Except for the new Intel dual-core processors, I'd advise small businesses to stay away from multiple CPU servers.

The worst thing you can do, and this is not uncommon, is to specify a multiprocessor server but not go that last mile and buy the 2nd processor, instead putting it off for a future upgrade that never happens.

Another school of thought says "Scale out not scale up" in other words buy 2 single-CPU servers instead of one multi-processor one.

64-Bit Processors - 64-Bit Windows

These are both available right now and are set to replace their 32-bit equivalents before long.

Intel's first attempt at 64-bit processors was called Itanium and wasn't a success. AMD then brought out their own 64-bit processor using x64 architecture. Intel have followed up with their own x64 compatible processor and Microsoft have released x64 versions of Windows XP and Windows Server 2003 so the 64-bit revolution has started.

From the end of 2005 I would advise buying only 64-bit server hardware with maybe a dual-core 64-bit processor.

As 32-bit Windows runs perfectly happily on x64 processors you can delay the move to a 64-bit operating system until 64-bit drivers for all common hardware components are available which is not the case right now.

What are the advantages of 64-bit over 32-bit? Instead of being limited to 4 gigabytes of memory you can have up to 1 terabyte and 64-bit CPU registers make floating-point calculations much faster.

The current 64-bit Microsoft Windows operating systems are able to work with up to 128gb of RAM.

Imagine a motherboard fitted with 1000 x 1 gigabyte memory modules.

SCSI RAID Controllers

These can cost over £300. Motherboards often have simpler built-in IDE hardware RAID controllers, otherwise a Promise IDE RAID controller PCI card costs around £80.

When you choose the type of  hard drives you, of course, set the type of RAID controller you need.

Redundant Hot-Swap Power Supplies

A fantastic feature but too expensive for the moment.

Storage Area Networks

This is a hard disk array on a separate high speed network segment usually only accessible to servers. The theory is that it's more efficient and easier to upgrade this type of network storage than when each server has its own hard drives for storing network data. The network traffic generated by accessing a SAN disk array doesn't clog up the main network segment. One centralised SAN storage device may hold the whole of a company's data from all of its separate offices.

Network Attached Storage (NAS) is similar but here the storage device is on the main network and will add to network traffic.

Server Diagnostic Cards

This is a PC-on-a-card which plugs into a PCI slot inside a server and monitors its operation. The card has its own network socket and IP address so it can be contacted if the server crashes and, as the lead to the reset button loops through it, the card can be instructed to "press the reset button"

400 Gigabyte IDE Hard Drives - onwards to ever greater storage capacities. Huge capacity hard drives can make it harder to keep your data organised and accessible. They're also a headache to backup.

DVD Read/Write - Over 4 gigabytes on a disk. A good idea? Maybe, maybe not. Servers can receive a sudden large demand on their resources which may disrupt the steady flow of data required for CD/DVD recording.

Processors with Hyper-Threading - This is a standard feature of Intel processors, 3gHz and faster, where 1 physical processor appears to Windows as 2 logical ones. Two processors for the price of one, it's supposed to make things run faster.

Windows 2000 doesn't understand it and thinks that a CPU with hyper-threading is 2 separate processors. This uses up the 2 x CPU allowance of Windows 2000 Professional and half of the 4 x CPU allowance of Windows 2000 Server.

Hyper-threading has not proved a great success but the next generation of Intel CPUs will genuinely have 2 separate processors on one chip.

Rack-Mount Cases - Desktop cases cost around £40 while server cases cost £100s, sometimes more than a £1000 - why?

This is the new serial bus that is set to replace the parallel bus which is PCI. As with IDE to SATA, a serial bus is proving faster than a parallel one.

This is currently fitted to the Intel 915 and 925 chipset motherboard and is not backwards compatible with PCI cards.

Buying the components individually and assembling the server yourself is not such a radical idea ( I do it all the time). You'll have to provide your own hardware support - faulty components, still under warranty, will be replaced by the manufacturer but, as this usually takes a week or so, you'll need to have rapid access to spares to keep things going in the meantime.

You won't save any money assembling it yourself as suppliers of complete systems can get the components cheaper than you can. So why would you want to do it?