How To Build a New PC for Under £150

Upgrading your PC – Mike Walker

I have followed the articles in MicroMart on upgrading your PC with interest as I have recently carried out a similar exercise myself. I was running an Evesham Athlon 500 (October 1999 vintage) with 500MB of RAM, 7200rpm 20MB disk and two 19 inch monitors driven by a Matrox G400 video card and a further PCI card-driven monitor.

Since I use this to follow share prices and chart them in real time, performance and reliability are key. I had upgraded to Windows XP which is a great improvement, but although my system could cope, it was slow and underpowered when dealing with times when trading volumes jumped.

Since a new system would involve purchasing lots of duplicated hardware and cost at least £450 for a bare system without monitors, I decided to upgrade the processor and motherboard and to utilise parts as much as possible from the old system.

Having carried out research, it was clear that a Duron 1200/Elite K7S5A CPU/motherboard combination was the most cost effective route (A Duron 1300 costs about 20% more for 10% more power!).

In particular, I could use my existing memory and buy faster RAM at a later date – my existing RAM is PC100. My disk was fast enough and since I rarely store any pictures, 20MB is perfectly adequate and fast enough as I defrag with Norton Speed Disk three times a week.

Since I dislike noise sitting at a desk with a PC for 12 hours a day, I purchased a standard fan and heatsink for £10 and a replacement Thermaltake TT6025A 2B fan for £10 which runs at lower revs (4,700) and has only a claimed 28dbs noise levels. To improve case cooling, I bought an Akasa case extractor fan which fits in a PCI slot.

Unfortunately, the existing Power Supply was only 200 watts – 300 was needed so I bought an Enhance low noise 300P watt PSU.

Having assembled all the various bits – total cost £155 or just £5 over my original budget of £150 – I set to work by:

  • Stripping out the old motherboard first. Piece of cake;
  • Assemble CPU with heatsink and the (non Thermaltake )fan. Piece of cake;
  • Add memory from old mainboard. Piece of cake;
  • Put new mainboard into old case. Snag!

Although the case was ATX and the old mainboard was also ATX, the new one is about 3cms (1 inch) deeper and fouled the (empty) cage attached to the case for extra hard disks or CD/DVD players. Well, I would not need it but I could not remove it, so out with the CD, floppy and hard disk drives – 12 screws, 10 minutes – out with my junior hacksaw.

Ten minutes later and a bit of metal removed and the remains bent over, there was room for my new mainboard (and a little blood when I cut myself on a sharp edge!).

Attach old mountings (in different positions from the old board), put in new power supply, replace CD floppy and hard disk drives and we are back together. Before I put any cards in, switch on power to test fans – after having checked all connections first. Beep and power up so it clearly was working.

Switched it all off, added all my cards, attached 2 monitors and fire up. Nothing works.!

Test with old motherboard. It does not work! Realised I had switched old hard disk cable to a new cable – it must be faulty. Switch back to old one and reinstall new mainboard. Works perfectly and posts but does not recognise Windows XP on my hard disk.

No problem, as I had expected this and had backed up all my data and settings to CD (XP Files and Settings transfer facility is EXCELLENT).

I then flashed the BIOS to the latest version which I had downloaded before onto a floppy, reloaded XP from scratch and all my other programs plus Windows Updates (all 40MB!) and some drivers from the internet.

Total time taken:

  • To rebuild computer from scratch (including hack sawing!): About 3 hours, up to reloading new BIOS.
  • Total time to reload software including upgrades: About 4 hours!

Was it worth the efforts? Well I have SiSoftware Sandra as a free download and the Whetstone benchmarks were as follows:

  • Old system: 679
  • New system : 1652 – so a 140% power increase!

By comparison an Athlon XP 1600 is 1940 and and an Athlon Thunderbird 1.2 GHz is 1635.

Much faster and smoother and all my systems ran perfectly – and remember that I had not changed my RAM – so faster RAM could give further improvements of 10-20% plus in benchmarks.

I then changed the CPU fan to the Thermaltake and, using Mainboard Monitor 5 (MBM), I obtained the following CPU temperature readings:

  • Before new fan: 33C
  • After new fan: 29C

and less noise as well.

I am now auctioning my old mainboard and CPU on Ebay (! Sorry) and expect to raise about £40 – £60.

So for a net expenditure of around £120, I have a computer nearly 2.5 times faster than my old one, almost as fast as an Athlon XP 1600 and there is scope for further performance improvements. I only used 2 screwdrivers, a pair of pliers and – my hacksaw!

Any person competent in DIY and not afraid of electrics could do what I did, although you do need to read the motherboard manuals and work out which wires go where – but that is not difficult if you are logical and careful (You do not need any electronics expertise – just an ability to read the motherboard manuals and attach about 8 wires to the correct places on the motherboard).

Would I do it again? Yes.

Easy to do, quite a bit of effort on the software side but rewarding and the results are a transformation. My charts now are much smoother when activity is high and switching applications under XP takes 1-3 seconds instead of 5-10.

The “How To Build a PC” article at and the articles in Micromart (together with the adverts) helped a lot – I kept both at my side and referred to them as I went along.

Mike Walker

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