AMD's Chipsets - 790FX, 790X And 770
Alongside the new Phenom processor, AMD is also introducing three new chipsets for the AM2+ socket, all of which are compatible with the PCI Express 2.0 standard. The biggest of the three chipset versions, the 790 FX, supports up to four graphics cards running in a Crossfire-X configuration. This functionality will only be unlocked in January of 2008 through a new driver. AMD promises that the four-card configuration will offer three times the performance of a single card.
| AM2+ Chipsets with DDR2 | |||
|---|---|---|---|
| 790FX | 790X | 770 | |
| Hypertransport | 3.02.0 | 3.02.0 | 3.02.0 |
| PCIe 2.0 | 2x 16X1x 16X + 2x 8X4x 8X | 1x 16X2x 8X | 1x 16X |
| Crossfire X | max. 4 Cards | 2 Cards | not supported |
| Code Name | RD790 | RD780 | RX780 |
MSI demonstrates AMD quad Crossfire
In addition to the PCIe lanes for the graphics cards, the chipset offers six additional PCIe lanes to attach other devices such as a network adapter etc.
For now, the chipsets will be paired with the SB600 southbridge. Starting in January of 2008, the motherboard manufacturers will be able to use AMD's newer SB700 southbridge in its place. This brings the following changes to the table:
| Comparison SB600 vs. SB700 | ||
|---|---|---|
| SB600 | SB700 | |
| SATA | 4 | 6 |
| IDE | 1 | none |
| USB | 10 | 12 |
One of the most noteworthy features of the AMD chipset is its low power consumption. The chipset is rated at a TDP of only 10 Watts, which is due in large part to its 65 nm production process. For reference, Intel's chipsets are rated at a TDP of 26 Watts and use a 90 nm process.
The pricing of the chipsets is another highlight, as boards built around the smallest version will be available starting as low as €69.
