Time to upgrade your PC? 50 old and new AMD and Intel CPUs rated and reviewed

Whether you’re upgrading or building from scratch, one of these 50 processors will fit the bill, but which one?

It has been the quietest of revolutions, but make no mistake: the CPU landscape has changed completely. New technologies have blown away the old-school, with performance rocketing while power consumption and prices plummet.

Even the cheapest processor in this test, which costs an almost throwaway $70, is faster than the once top-of-the-line 3.2GHz Pentium D.

Then, just as we were going to press, Intel sent us its new range and effectively retired its biggest sellers of recent times.

The performance end of the processor world is a particularly exciting place, with the two major manufacturers taking radically different approaches: AMD is squeezing ever greater bang per buck from its flagship Phenom II design, while Intel is undertaking a fundamental revamp of its CPU line-up.

At the other end of the scale, the famous Sempron, Celeron and Pentium names are still around, although not in their traditional guises; today, they’re using technology from last generation’s cutting edge to keep them fresh.

Cheap as they are, these CPUs are still viable options for those upgrading or repurposing an existing motherboard.

Alternatively, if you’re building a system from scratch, you’ll want to know which platform is the cheapest, most flexible and future-proof.

Analysis, plus how we test

The most eye-opening way to survey the current CPU landscape is to plot price against performance, so once again we’ve done just that.

The graph below gives an instant appraisal of a CPU’s position compared to its peers: with the benchmark score along the X-axis and price up the Y-axis, those CPUs nearest to the bottom-right corner can be instantly seen to give the best bang-per-buck.

The most apparent trend is that AMD’s CPUs beat Intel’s for pure value. The Athlon II line (red) is a good distance beneath Intel’s Core 2 parts, while the Phenom II line (yellow) is way below all but the best of the new Core i3 and i5 parts.

Based on price alone, AMD’s aggressive strategy is working.

Of course, that isn’t the whole story: motherboard prices need to be factored in, as does the longevity you’ll get from Intel’s newer platforms. But it gives you an at-a-glance idea of the situation.

The new 32nm Core i3 and i5 processors are the stars of Intel’s range, with several running AMD close. It’s their newness that gives them a slight price disadvantage, but that will gradually diminish as stocks rise and prices fall.

By contrast, the much-loved Core 2 Duo and Quad parts now sit far too high on the graph, an indication that Intel wants to phase them out.

To the left of them, the ageing Pentium and Celeron lines just can’t match the Athlons for power, yet they cost as much or more.

And then there are the usual laughable anomalies: we’ve deliberately excluded as many older Extreme Edition processors as we can – they’re just too hard to find at retail – but the Core i7-975 Extreme keeps that flag smugly fluttering.

The full graph would has to stretch upwards by a further $300 just to accommodate its excesses.

This graph charts street price against benchmark performance. The perfect CPU would be found in the bottom-right corner, so the closer to that the better the value. (Click on image for larger size)

How we test

Every CPU is fully tested using our comprehensive suite of real-world application benchmarks – which includes Photoshop, Office and several media encoding programs.

Obviously, given the multiple platforms being tested, we can’t use a single test rig for every CPU. Instead, we stick to the same 2GB of DDR3 RAM and a 160GB 7200rpm hard disk, and choose a suitably flexible motherboard for each CPU socket to allow us to delve into the BIOS.

For Socket AM3 parts we used an MSI 790FX-GD70; for Socket LGA 775, it was a Foxconn BlackOps.

For the LGA 1366 Core i7s we tested with an MSI X58 Platinum, but the LGA 1156 parts required two separate boards: a Gigabyte P55A-UD6 with a P55 chipset for the 45nm parts, and an Intel test board with H55 chipset for the new 32nm parts.

In the case of these brand-new CPUs, we were supplied only a few early samples, so for unavailable models we replicated their clock speeds by altering the FSB and/or multiplier on the samples we had; where this is the case, the final score is an estimate.

We wouldn’t expect the actual score to differ by more than 1% or so.

50 CPUs rated and reviewed: click on image for larger size

This Group Test appeared in the April, 2010 issue of PC & Tech Authority Magazine