Server vs. high end desktop

Somewhere between a high-end PC and a true server, the distinction does blur, but generally a server is built with reliability and throughput in mind and a desktop places more emphasis on the user interface and keeping the price low.

The items that drive up the price of a server:
drives - a server should have some sort of RAID that provides continued operation if a drive fails. A RAID card is about $1k minimum and SCSI drives are more expensive than their desktop IDE counterparts plus there is a redundancy cost (the price per megabyte doubles if you use mirroring - somewhat less if you use RAID-5).
In addition, disk speed is more important on a server because there may be many workstations waiting to write data to the disk ratherthan just one.

Backup systems - few desktops have any backup system. A 35/70gig DLT drive will set you back between $5-7k.

RAM - lots of it. Most of my servers have 2gig of RAM and we use error correcting RAM (ECC) when available. On a Compaq server, 2gig of RA

To finish my note, 2gig of ECC RAM can add $10k to the cost of a server.

Finally, there is redundancy and hot-swapping. Few desktops must be up and running on a 7x24 basis but servers are designed to permit hot-swapping of power supplies and drives without taking the server down. This adds additional cost not only for the redundant components but also for the engineering and infrastructure to make it all work.

If performance, uptime and the ability to recover quickly from a disaster arenot major issues, there is no advantage to investing the additional money in a server-class computer. But if those issues are important in your operation, trying to make-do with workstations is probably a risky proposition. It really depends on how your business interacts with the network and how expensive downtime is for you. If you stand to lose $1,000 per minute of downtime, a $35,000 server starts looking like a pretty good investment.

paul

One other comment I wanted to add. A cluster of workstation-class computers can equal an expensive server in both performance and reliability. One notable search engine (google) runs on a boatload of Linux servers running on clone hardware.

paul