AMD has launched two new quad core processors, the Athlon II X4 620 and 630. Announced at $99 and $122, they are clocked at 2.6 and 2.8 GHz respectively. How has AMD managed to bring them out so cheaply and how do the processors perform?
A third die at 45nm
Following on from the Phenom II X4 and the Athlon II X2, the Athlon II X4 enjoys a third die engraved at 45 nm. The new chip then is not an assembly of two Athlon II X2s or a Phenom II X4 with the L3 cache disactivated (even if in practice, that may also be the case): the Athlon II X4 integrates 4 cores on its silicon die, each with 128 KB of L1 as on all recent AMD processors. The L2 cache is 512 KB per core, as with the Phenom IIs, which is half the L2 cache on the Athlon II X2. Otherwise you’ll find the HyperTransport 3 bus and DDR2/DDR3 memory controller used by all AM3 CPUs.
Of course, it is much smaller as it is made up of 300 millions transistors that fit on 169 mm² of silicon, as against 258 mm² for a Phenom II X4. This means that AMD can engrave more processors per wafer and therefore drastically reduce production costs.
Compared to the Intel offer, we can see that the Athlon II X4 is around the same size as a Core 2 Quad from the Q9x00 (Q9300/9400) range. These Core 2 Quads are based on the assembly of two Penryn dies with 3 MB of cache that are used on their own on the Core 2 E7xxx but also on the Pentium E6xxx and E5xxx (with 1 and 2 MB of L2 cache deactivated respectively). The same die is also used for the Q8x00 (Q8200/8300/8400), with just 2x2 MB of L2.