More than just a relic of AMD’s original Spider platform, the 790FX remains the company's only real enthusiast northbridge. The newer SB750 southbridge offers modern peripheral performance too, while DDR3 support via AMD’s latest on-die memory controller is the latest performance trend.
The big reason you'd choose a 790FX over the more “modern” 790GX is its 38 PCI Express (PCIe) 2.0 pathways, which can be configured as two x16, four x8, or a mix of single x16 and two x8 sets, with six pathways to spare. As with the 790GX, AMD’s third-generation HyperTransport interconnect links the 790FX to the AM3 processor, so the only two things more “modern” about the 790GX are its onboard Radeon HD 3300-series graphics core, which enthusiasts don’t want anyway, and its release date.
We have to suspect that most AMD enthusiasts haven’t considered shifting over to AM3 yet because of the lack of top-range clock speeds for DDR3-supporting processors (plus the fact that half are triple-core models, while the other half are quad-cores with cut-back cache).
AMD will release updated models soon, but we can’t give you the speed or the date (Ed.: Here's a hint: check back tomorrow). Until then, many are choosing the Phenom II X3 720 Black Edition for its excellent reputation in overclocking, since most programs can’t take advantage of all four cores of the slower-clocked Phenom II X4 910.
| Socket AM3 Processors | |||||
|---|---|---|---|---|---|
| Model | Frequency | L3 Cache | Voltage | Model # | Socket |
| Phenom II X4 910 | 2.6 GHz | 6 MB | 0.875-1.425V | Tray: HDX910WFK4DGI | AM3, AM2+, AM2 |
| Phenom II X4 810 | 2.6 GHz | 4 MB | 0.875-1.425V | Tray: HDX810WFK4FGI; PIB: HDX810WFGIBOX | AM3, AM2+, AM2 |
| Phenom II X4 805 | 2.5 GHz | 4 MB | 0.875-1.425V | Tray: HDX805WFK4FGI | AM3, AM2+, AM2 |
| Phenom II X3 720 BE | 2.8 GHz | 6 MB | 0.850-1.425V | Tray: HDZ720WFK3DGI; PIB: HDZ720WFGIBOX | AM3, AM2+, AM2 |
| Phenom II X3 710 | 2.6 GHz | 6 MB | 0.875-1.425V | Tray: HDX710WFK3DGI; PIB: HDX710WFGIBOX | AM3, AM2+, AM2 |
- 790FX Is Still The King
- Socket AM3 Motherboard Features Comparison
- Asus M4A79T Deluxe
- DFI LANParty DK 790FXB-M3H5
- Gigabyte GA-MA790FXT-UD5P
- MSI 790FX-GD70
- Test Settings
- Benchmark Results: 3D Games
- Benchmark Results: A/V Encoding And Productivity
- Benchmark Results: Synthetic
- Overclocking, Power, And Heat
- Conclusion

(2.80 GHz, 86.0 MB Cache)
I never knew any AMD processors had that much cache!
Super CPU!
1.66% better than the worst performer in the tests. :-)
Not much point in throwing that much GPU horsepower at a motherboard review; the card Thomas used is our current reference--and it's more than ample for showcasing the differences between these boards.
If you want to see quad-CrossFire for any specific reason, feel free to let us know and we can put together a story idea!
Consistent would have been better if not for the fear of people pointing out ever tiny inconsistency. Just remember, if you're 5'11" tall it's clear to just about everyone that you're not 6'!!!
Could you clarify that a bit Chris? Are you saying you would not expect any difference in crossfire between the MBs? If so, that's OK. However, if there's going to be a difference, that is the main reason to buy a 790FX. If you aren't going to crossfire might as well get a GX.
I suspect the chipset isn't the whole story and the various manufacturers could still screw up the PCI-E voltages or something
It depends on the numbers you're looking for. I interpreted the OP's request to mean he wanted performance results with 4870 X2s, which are overkill for comparing these boards. If it's a matter of comparing PCI Express scaling (the reason for going FX instead of GX), check out this piece: http://www.tomshardware.com/reviews/crossfire-pci-express,2095.html. It isn't on the AMD platforms, but it still illustrates fairly well how much/little performance you'd lose with PCIe 2.0 x8 vs. x16.
Granted my request isn't based on the real needs of the consumer, it's more of a scientific curiosity behind it. But I remember a while back tom's had an article about nvidia's SLI with 2, 3 or 4 cards in different configurations and that was an interesting read.
PS: Just to clear something up in the 2 x 4870X2 vs. 4 x 4870 or other versions. I know that 4x4870 are more $$ then 2x4870X2 but if you buy a 4 slot PCIe motherboard what if you start out with a single 4870 or 4890 and just add in cards over the period of a year since prices change and people might not have all the cash to get 4 cards at the same time.
"We guys" just made a suggestion since Chris stated he's opened to ideas. The asrock X58 article a few days back is another good example of a story that can be looked at from a more technical perspective. Since that board and these two AMD ones share 4 PCIe ports and ATI & Nvidia cards support ATI STREA/CUDA one would be inclined to have a look beyond the "can it run crysis" comment. And I'm sure finding 4 identical cards isn't an issues since the time that takes to right an article wasn't up for debate.