AMD puts out a faster 780G

AMD CURRENTLY HAS the best integrated graphics chipset on the market, the 780G, but it was just dethroned. Luckily, it is by a derivative chipset, the AMD 790GX, an upclocked 780G with a new south bridge and a lot of tweaks.

To be fair, lets start out by saying that it is not just a 780G with the clock turned up, but a third generation 780G. The first one was the one you know and love, until today the fastest integrated chipset out there bar none. The second generation started out with the chipset which went into the Puma laptops, and it brought some power-saving twists here and there. The third gen is the 790GX, and it has all of those additions, and some performance tweaks on top.

From the first time we showed you pics of the board, you will notice that it has two PCIe2 16x slots, and that is the key to the naming difference. In AMD newspeak, the 780 series has one 16x slot, and the 790 has at least two. We won't mention how suffixes confuse the issue, that would be double plus ungood. In any case, the PCIe2 lanes are the same, it just splits them into two 8x electrical channels, more than good enough for what you need to do.

How fast is fast? Well, the 780V ran at 300MHz, the 780G at 500, and if math is your forté, you can probably guess that the new one runs at 700MHz. Purely coincidence, but it is a nice thing to point out. This should bump the the 3DMark06 scores from the mid-1600s to the low- to mid-2000s. For an integrated GPU, that is a stunning achievement.

If you add in Sideport memory – basically an on board 64 or 128M DDR2 or DDR3 chip in either 64 or 128 bit width – this should add an even larger chunk to the score. A local frame buffer saves an immense amount of travel to and from main memory, and can be used to more aggressively put the memory controller to sleep while keeping video active. This is one of those power tweaks we mentioned earlier.

The GPU itself is basically an ATI RV610 core. It has all 40 shaders of the older 34x0 GPU, along with AVIVO HD and UVD. It can hardware decode all HD codecs currently in use, and saddle anyone dumb enough to buy a Blu-Ray drive with all the crushing DRM that platform has to offer. The video outs can have DVI, VGA, HDMI and Displayport, pick any two to be active at any time.

There are also 22 PCIe2 lanes, most commonly found in a 2 8x and up to 6 1x config. Four more are used to connect the SB750 south bridge. This SB brings 6 SATA2 channels, one PATA, 12 USB2.0, PCI and HD audio. Nothing special there, but lurking beneath the surface, there is a lot of goodness.

The major upgrade from the SB700 to the SB750 is simple, it adds RAID5 to the mix. With 6 SATA channels, this could have some major opportunities, especially for a home cinema box with a few 1.5TB drives slapped on it. To make this much simpler, ATI threw in a completely revamped Raid control panel to make life simpler.

More importantly than that, another one of the new features is called ACC, or Advanced Clock Calibration. To the buzzword averse, this brings something quite interesting to the table: a communications channel from the SB750 to the CPU, basically a tweaking path and feedback loop. What it does is allow all the boot setting and some of the usually factory-set fuses to be overridden and reprogrammed if you have an unlocked CPU.

ACC may not sound like much, and it is most definitely not a user-controllable option, but it should help. What it does is allow flexibility and remove hidden bottlenecks. If you crank up the main CPU voltage, you may or may not be changing several other voltages and clocks on the CPU that very well could limit the performance in a spectacular way. With luck, ACC will break this glass ceiling by changing the settings you can't automatically.

The early 780Gs were not meant for the insane overclocker set, and even though they had a lot of options to fiddle with, they lacked one big must-have: power delivery. The 780G we reviewed in March simply would not boot with a prototype Phenom 2.6GHz/9950. That chip drew 140W, and the humble 780G board would not even post with the CPU in.

The new 790GX takes that into account, and provides full power for 140W CPUs and more should you chose to play with the AMD Overdrive utility.

Speaking of which, there is a completely revamped AMD Overdrive program that launches with the 790GX. It is black and green instead of the older more staid color scheme, and quite simply looks a lot better. If you have a newish AMD box, go grab it here, it is well worth the price.

In the end, the 790GX is simply a 780G with a lot of tweaks, features, and RAID5. The base part was so damn good that it is hard to find things to improve. More speed is always a good thing, as is power savings and potentially a few more MHz from your CPU. Hard to argue any of those bullet points.

The only down side is cost. 780G boards run from about $80 to $110, 790GX boards are $100 to $150, but both prices will fall a bit as soon as they are out for a bit. The low end 790GX boards are a pretty solid deal, and the high end ones are quite feature packed, but a bit hard to justify the added price. If you want a home theater box with local storage, RAID5 is mighty valuable.

Building a system piecemeal and want to end up with a higher end crossfire box? Again, the 790GX is a great starting point.

For everything else, there is the 780G, and that is not exactly a bad system. The only competition to the 790GX is it's little brother, in some ways a great problem for AMD to have, and in others, the worst of both worlds.

Bottom line, the consumer wins, there is a wider spectrum of choices on the market, and that is never a bad thing.

Hard to fault more and better.µ