AMD Phenom X3

After impressing us with its new quad-core Phenom X4 processors earlier this month, AMD has followed up by finally delivering the industry's first triple-core x86 processors, which it originally promised last September .

The three new chips are, logically enough, designated the Phenom X3 series. They're based on the same internal design as the X4 parts, with the same cache arrangements (512KB L2 cache per core, plus 2MB shared L3 cache) and the same 3.6GHz effective HyperTransport. The only major difference is that one of the cores is completely disabled. AMD calls this variant the Toliman core.

The low-end part - the X3 8450 - is the slowest Phenom yet, at 2.1GHz, with the mid-range X3 8650 and top end 2.4GHz X3 8750 clocked at 2.3GHz and 2.4GHz respectively. Oddly, there's no 2.2GHz part, though there's clearly a space for it in the line-up. Despite having one core fewer, the X3s have the same 95W TDP as most X4s.

We've noted before that Windows applications typically derive only a small benefit from extra cores. It's no surprise, therefore, that the triple-core Phenoms aren't far behind the quad-cores in our real-world benchmarks, with the three new parts scoring 1.25, 1.35 and 1.40 at their respective stock speeds.

That's a difference of only around 7% between identically-clocked X3 and X4 parts, and makes the X3 8750 slightly faster, overall, than the X4 9550, which scored 1.39.

As our graph shows, the Phenom X3 doesn't break new ground in terms of bang-per-buck: AMD's high-end Athlon X2s already offer similar performance at a similar price. But the Phenom brings a lower TDP to the table (the fastest Athlons draw 125W), plus an extra core, which can only help as multithreading becomes more pervasive. And, despite these improvements, Phenoms are currently slightly cheaper than comparable Athlons.

So while the X3 may not be as revolutionary as the X4, it's a wholly positive evolutionary step. If you're looking for a capable processor that doesn't cost the earth, it's an excellent choice.

Author: Darien Graham-Smith