The processorsFor this test, we managed to get our hands on both the Athlon II X4 620 and X4 630.
It is interesting to note that the voltages of the two processors differ by quite a bit: the Athlon II X4 620 works at 1.125V in idle and 1.4V in load, as against 1.025V and 1.325V for the Athlon II X4 630. This can vary from one processor to another depending on the quality of the die, AMD simply saying that the nominal voltage is between 0.925 and 1.425V.
Energy consumption is measured in two places: processor consumption alone at the ATX12V socket and with a clip-on ammeter and total consumption with a power meter at the wall socket, always loading the machine with Prime 95. Watch out, then, for your other components such as the graphics card or hard drive, which are in idle when these readings are taken.
In the case of the reading at the ATX12V we only compare readings within the same platform so as to be able to compare apple to apple; on AM3 for example, the memory controller is supplied by this power source but on the LGA1156/1366 platform, the uncore part of the processor is supplied by the standard ATX connector.
The Athlon II X4 620 remains quite economical both in idle and in charge, a long way down on the X4 965. Strangely, in spite of its lower voltages, the 630 is lot more demanding both in idle and load. What this probably means is that although the Athlon II X4 620 is a “Propus”, the 630 is actually a “Deneb”, namily a chip with 6 MB of L3 but which are disactivated.
The comparison with socket 775 is not necessarily in favour of AMD as the configuration based on the Q9400 proves more economical both in idle and in charge. The scores are nevertheless reasonable.
Naturally, we tried to overclock the processors. The Athlon II X4 620 managed 3.2 GHz without increasing its voltage of 1.4V, which leads you to think that the voltage is somewhat overestimated. At 1.5V, we stabilized it at 3.4 GHz in 4 instances of Prime 95.
Version 630 was also stable up to 3.2 GHz without us having to change its voltage of 1.325V. We stabilized it at 3.4 Ghz at 1.4V and 3.6 GHz at 1.5V. Although overclocking is by its nature a bit random, the results for the Athlon II X4 620 were a little disappointing. Things are a bit better for the 630 but nothing exceptional.