
The Phenom II X6 will work in all existing Socket-AM2+ and AM3 motherboards that can 1) support the 125W TDP of the processors, and 2) have BIOS support (apparently over 160 boards at launch). Despite this impressive showing of backwards compatibility, we also get a new chipset today for those of you looking to build a new system instead of upgrade.

The 890FX is a mildly updated version of AMD’s 790FX chipset, mostly adding AMD’s SB850 South Bridge with 6Gbps SATA support. The number of PCIe 2.0 lanes and other major features remains unchanged.
| AMD 890FX | AMD 890GX | AMD 790FX | |
| CPU | AMD Socket-AM3 | AMD Socket-AM3 | AMD Socket-AM3/AM2+ |
| Manufacturing Process | 65nm | 55nm | 65nm |
| PCI Express | 44 PCIe 2.0 lanes | 24 PCIe 2.0 lanes | 44 PCIe 2.0 lanes |
| Graphics | N/A | Radeon HD 4290 (DirectX 10.1) | N/A |
| South Bridge | SB850 | SB850 | SB750 |
| USB | 14 USB 2.0 ports | 14 USB 2.0 ports | 12 USB 2.0 ports |
| SATA | 6 SATA 6Gbps ports | 6 SATA 6Gbps ports | 6 SATA 3Gbps ports |
| IOMMU | 1.2 | N/A | N/A |
| Max TDP | 19.6W | 25W | 19.6W |
You get IOMMU support (an advantage over 790FX) and despite the chipset being built on TSMC's 65nm process, it pulls less power than the 890GX as it lacks any integrated graphics.
To keep the review length manageable we're presenting a subset of our results here. For all benchmark results and even more comparisons be sure to use our performance comparison tool: Bench.
| Motherboard: | ASUS P7H57DV- EVO (Intel H57) Intel DP55KG (Intel P55) Intel DX58SO (Intel X58) Intel DX48BT2 (Intel X48) Gigabyte GA-MA790FX-UD5P (AMD 790FX) MSI 890FXA-GD70 (AMD 890FX) |
| Chipset Drivers: | Intel 9.1.1.1015 (Intel) AMD Catalyst 8.12 |
| Hard Disk: | Intel X25-M SSD (80GB) |
| Memory: | Corsair DDR3-1333 4 x 1GB (7-7-7-20) Corsair DDR3-1333 2 x 2GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 280 (Vista 64) ATI Radeon HD 5870 (Windows 7) |
| Video Drivers: | ATI Catalyst 9.12 (Windows 7) NVIDIA ForceWare 180.43 (Vista64) NVIDIA ForceWare 178.24 (Vista32) |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows Vista Ultimate 32-bit (for SYSMark) Windows Vista Ultimate 64-bit Windows 7 x64 |
"While mainstream CPUs are down at 65nm". I think you meant 65w.