The relative guide to upgrading

THE FIVE-YEAR-OLD PC

Five years is a long time in computing terms, especially if you consider Moore’s Law, which essentially says that processors will double in performance every two years. In theory, a five-year-old PC should take five times longer to complete a task, such as encoding a video or applying an effect in Photoshop, than the equivalent PC today.

Although it’s easy to look at clock speeds to try and disprove this theory – today’s processors run only a little faster than they did in 2006 in terms of GHz – don’t forget that modern chips have more cores than they did back then. A typical PC from 2006 had a single- or dual-core processor and 1GB of RAM. Check the specifications of a budget PC today, and you’ll likely find a triple- or quad-core processor and 4GB of RAM, showing that Moore’s Law is just about staying true.

A typical PC system from 2006. This one has a single core Intel Celeron 430 processor

Of course, the other thing to remember is that every PC in 2006 ran Windows XP. Given that support for XP has all but ended, it makes sense to upgrade to Windows 7. Although you could do this without upgrading your hardware, you’ll probably find that 1GB of RAM just isn’t enough to keep multiple applications running smoothly.

MOTHERBOARDS AND CHIPSETS

One of the main limitations of a PC this old is the motherboard and, more specifically, the chipset and processor socket it has. If you own an Intel-based PC, it probably has an LGA775 processor. Unfortunately, older chipsets like the Intel 915PL don’t support the later dual-core Core 2 Duo and quad-core Core 2 Quad chips. The best you can upgrade to is the fastest Pentium 4 that Intel released: the 3.8GHz 670. Although it sounds fast, this single-core processor can’t match Core 2 Quad chips with three extra cores, so if you do find you have a chipset that doesn’t support Core 2 processors, you should consider buying an entirely new PC base unit.

You may be more fortunate and have an Intel 945 or 965 chipset. These support Core 2 Duo and Core 2 Quad processors, but you still need to check your motherboard manual to make sure it supports the particular model, as front side bus speeds vary. For example, the Core 2 Duo “Allendale” E4xxx chips had 800MHz FSBs, while the later “Conroe” E6xxx versions had 1,066MHz and 1,333MHz FSBs. The E7xxx models all had a 1,066MHz FSB, while the most recent E8xxx series had 1,333MHz FSBs. If your motherboard doesn’t support the processor’s FSB speed, it simply won’t work.

It’s also highly likely that you’ll need to update your motherboard’s BIOS in order to run a newer processor. Usually, there’s no need to update the BIOS as manufacturers release new versions, so you may still have the original version that the motherboard shipped with. See the box on page xxx for more information on upgrading your BIOS.

Plenty of PCs with AMD processors were sold in 2006, but as with their Intel counterparts, there were different and incompatible versions. Earlier models had motherboards with the 939-pin socket, while later PCs had the newer socket AM2. As with older Intel LGA775 motherboards, the problem if you own a PC with a Socket 939 processor is that you can’t upgrade to a noticeably faster model, and certainly not a quad-core chip. Plus, you’ll be stuck with the original DDR memory, which is expensive to buy, even in small capacities. Sometimes you have to draw a line and our advice if you have a Socket 939 motherboard is to either replace it, or buy a new base unit.

If you have a motherboard with a Socket AM2, however, it’s a different story. For a start, you’ll have DDR2 RAM, which is faster and cheaper than DDR. Chances are that you have 1GB installed, split between two 512MB modules, and two spare slots. This means it’s easy to add more RAM without having to throw away your existing memory.

There’s also a good chance you’ll be able to upgrade to a faster processor. You may have a single-core processor such as the Athlon 64 3500+, running at 2.2GHz. Depending on your motherboard, you may be able to update the BIOS and install one of AMD’s latest Phenom II processors. However, if you’re on a tighter budget, there are still significant performance gains to be had by upgrading to a relatively inexpensive Athlon II chip.

WHAT TO BUY

It’s all very well seeing the performance gains in the graphs, but which upgrade is the best value? We picked only the best-value processors as potential upgrade options, but older processors can be hard to find in the shops. Your best bet is to search online retailers such as www.scan.co.uk as they tend to carry a much wider range. Bear in mind that prices are very volatile, so if you see another processor that’s similar to what we’ve tested with (say a Core 2 Quad Q8300 instead of a Q8200) at a lower price, then go for that instead. Likewise, memory prices fluctuate almost daily, so don’t be surprised if the prices we mention here are different from those you see online.

Starting with RAM, a 2GB kit comprising two 1GB PC2-6400 modules costs £16 including VAT. Alternatively, you can buy a single 2GB module for £11. If you already have a 1GB module and want to add another, make sure you check the exact speed and try and match it. Currently, a 1GB PC2-6400 module costs just around £9, which is clearly poorer value than the above, though at these prices it’s not a big deal.

However, while our test PC felt a little more responsive once we’d upgraded it to 2GB, the benchmarks show that there were virtually no gains in application performance. Clearly, there’s a much bigger gain if you upgrade your processor. A Core 2 Quad Q8200 (or Q8300) costs around £100, and could make your PC up to three times faster (this was certainly the case when upgrading from our Celeron 430).

If your motherboard doesn’t support the Q8200’s 1,333MHz FSB, another option could be the Core 2 Duo E7500. This has a slower 1,066MHz FSB and costs around £85 yet was almost as fast as the Q8200 in our tests. It was noticeably slower at encoding video, though, where the Q8200’s extra two cores showed their muscle. Conversely, the E7500 was faster in our image editing test (which isn’t optimised for multiple cores) thanks to its faster clock speed – 2.93GHz against the Q8200’s 2.33GHz.

If you’re upgrading an AMD-based PC, very similar rules apply. Our PC with an Athlon 64 3500+ and 1GB of RAM showed no noticeable improvement in our benchmarks after adding an extra 1GB of RAM. However, when we upgraded the processor to a Phenom II X4 965, the overall score shot up from 28 to 101. This isn’t a big surprise, of course, and the 965 costs a lot more than 1GB of RAM: £87 including VAT from Pixmania.

If you’d rather save money and upgrade to a modern dual-core processor, the Athlon II X2 250 is an excellent choice. It boosted our PC’s score to 86 (along with an extra 1GB of RAM), yet costs only £42. If you took this route, your PC would be roughly three times faster for a total price of just £67. Bargain.