AMD 780G Chipset and Athlon X2 4850e Preview

One of the 780G’s principal selling points is its HyperTransport 3.0 support, which dramatically increases bandwidth between the northbridge and compatible processor—a huge gain for an integrated graphics chipset, since the onboard GPU has to interface through the processor’s memory controller.

Of course, the Athlon X2 4850e that shipped with the platform wouldn’t work, since it’s limited to HyperTransport 1.0 link speeds. Instead, we subbed in a Phenom 9600 here, able to run at those HT 3.0 transfer rates. The HT 3.0 numbers were taken with the chip at its default 1.8 GHz HyperTransport speed. Then we manually de-tuned the chip to 1 GHz, simulating the bandwidth of a processor at the same frequency backed by a slower link.

When the AM2+ interface first surfaced, we remember hearing mumbling about a new socket interface soon after the release of AM2. It made sense—after all, why change the socket just to enable HyperTransport 3.0? Now that decision makes a lot more sense, since there’s clearly a lot of performance to be had from an integrated graphics chipset by simply turning up that interface between CPU and northbridge. The speedup is felt equally with or without the Hybrid Graphics feature enabled, so you can be sure of good scaling regardless of the graphics configuration you choose.