How does AMD respond to Lynnfield? Is it by drastically cutting prices on Phenom II? Nope. By introducing the world’s first quad-core processor to debut at $99. Now that’s cool.

It’s called the Athlon II X4 and its existence shouldn’t be any surprise. AMD quietly announced it along with the Athlon II X2 line.

Today we get two models: the Athlon II X4 630 and the Athlon II X4 620, priced at $122 and $99 respectively. The only difference between the two is clock speed; the 630 runs at 2.8GHz while the 620 runs at 2.6GHz. These are both AM3 chips meaning they'll work in AM3 motherboards with DDR3 memory or AM2+ boards with DDR2 memory.

This isn’t a harvested Phenom II nor is it a pair of Athlon II X2s, instead it looks like we have a brand new die on our hands (some Athlon II X4s will be crippled Phenom IIs but AMD insists that the new die will be used). The Athlon II X4 has four cores on a single die, but unlike the Athlon II X2 each core only has a 512KB L2 per core. You can tell by the die shot that the core-to-cache ratio is much higher than on the X2:

The 45nm Athlon II X4 Propus die

The 45nm Athlon II X2 die (note the larger L2 per core)

Like the rest of the Athlon II lineup there is no L3 cache. This helps keep the die small (and affordable) but also hurts performance:

At the same clock speed the Athlon II X4 should offer roughly 90% of the performance of a Phenom II X4.

The price is unbeatable. If we ignore the 630 for a moment, the Athlon II X4 620 is by far the cheapest route to four cores on the market. Intel’s most affordable quad-core is the Core 2 Quad Q8200 at $163, while AMD would previously charge you $163 for a Phenom X4 9600B. This is where the AM3/AM2+ compatibility play really helps out. Motherboard/memory costs are as cheap as possible thanks to AMD's incredible socket flexibility.

And just in case you’re wondering, yes, the Athlon II X4 620 actually delivers performance competitive with the Q8200 but for 60% of the cost. It’s not all that clear cut, there are some cases where the 620 is faster but others where the Q8200 is much faster. On average it ends up being a wash but you’ll want to pay attention to the coming pages to see how the cookie crumbles as it does vary from test to test.

Codename Propus

Overclocking isn't unfortunately as good as the Phenom IIs; the result of a conscious design decision or simply the early nature of the Propus die. That being said, without a single extra millivolt I was able to hit 3.25GHz on my Athlon II X4 620 sample - making it even more valuable. Extra voltage proved mostly useless, I could only approach 3.4GHz with an extra 300mV.

Let’s see, have I thoroughly ruined the surprise? Check. Now let’s get to the tests.

The Test