Technology often has an appeal that can't be quantified; and just as often has a name that can't be pronounced. While the GTX470 SOC isn't so bad in its condensed form, the full official title of ‘GV-N470SO-13I' is certainly a mouthful. We've seen a few entrants in the Super OverClock, or SOC series, and they're generally defined with a few noteworthy - and expensive - changes.
The first of these is the most basic: a core clockspeed increase from a reference speed of 607MHz to the SOC's 93MHz-faster factory clocks of 700MHz. This impressive boost represents an increase of 15 per cent, which the SOC will run at until the day it dies.
The next change is somewhat more expensive, as GIGABYTE has applied its latest heatsink design to the SOC; the Windforce X3. This heatsink is complex, consisting of a copper vapour chamber (licensed from Sapphire), which lifts heat from the core efficiently. A vapour chamber is essentially a large, flat heatpipe, and inside the ‘chamber' resides a series of wicks with a fluid inside. The fluid is heated by the core where it circulates inside the chamber via convection, and cyclically dumps its heat on the opposing side of the chamber. It's needed too; the stock GTX470 devours 215W at load, which the factory overclock only increases.
From the vapour chamber heat is distributed via three nickel-plated heatpipes into three separate heatsinks, the middle being flat, and the outer two angled slightly upwards to face the centre at roughly thirty degrees. Three fans are placed on these heatsinks, resulting in airflow that passes through the fins but doesn't cause as much turbulence as it collides with other airstreams. The Windforce X3 keeps temperatures at a low 37 at idle with a quiet 52.2dBA generated from the three fans; rising to an uncomfortable 72 degrees at a still-quiet 54.4dBA load. You'll be hard-pressed to hear this over standard system noise once installed in a case.
The third and perhaps hardest change to qualitatively analyse is the power delivery system. Rather than the boring reference design, where there are five chunky power phases to provide power, there are twelve smaller power phases that manage the load - and can provide a greater total. Thought of another way, it's like having five tanks in a skirmish against the same five tanks with supporting units; when the action heats up, it's better to have more available than not.
The backbone of this system is the NEC Proadlizer chip, of which the SOC is endowed with a total of five. These are astoundingly efficient and reliable, but along with their large cost comes heat - they became scaldingly hot under load and are not actively cooled, as they are located on the rear of the PCB. Airflow is a must to retain stability, and we wonder why no heatsink was applied.
Performance in benchmarks is great, returning a good score in 3DMark Vantage and Heaven, with our new Lost Planet 2 benchmark also taking advantage of the additional memory on offer to return some tasty frames. The SOC offers a rough performance boost of ten per cent compared to a reference-clocked card, and thanks to the impressive cooler, we could push it a further 12 per cent to 783MHz on the core, with memory rising by an additional 13 per cent.
You'll pay an extra $70 over the reference card to grab the SOC, and though it is expensive, the card is quite nice if you're after a little more by way of design. If you're after sheer performance, well, the 5870 still pips the SOC to the punch.
