AMD 990FX/SB950 Release: Asus SABERTOOTH 990FX and the MSI 990FXA-GD80
AMD Unleashes the 990FX: Paving the way for Bulldozer
Word of the AMD 990FX chipset first came around the end of last year. Speculation was brisk as to what new features it would bring, and when exactly it would help to usher in the age of Bulldozer to the world. Most thought that it would be a shrink of the then current 890FX, and the new SB950 southbridge would have improvements to the SATA 6G controller, as well as a native USB 3.0 implementation. Today we finally get to see the reality of the situation. It is not groundbreaking, nor is it altogether exciting, but it is certainly interesting.
The 990FX and SB950 chips are identical to the previous 890FX and SB850. They are the same silicon. For those hoping for new technology will be disappointed. But all is not lost! AMD did increase the HyperTransport specification from 3.0 to 3.1, which allows the HT bus to run at 6.4 GTPS as compared to the older 5.2 GTPS. This is in place to allow the upcoming Bulldozer chips to run the northbridge portion of the chip up to 3.2 GHz, and to give the CPU more bandwidth between the different busses on the board (eg. SATA, USB 3.0, and PCI-E connections).
The other advance, but one that is not covered as of yet due to there not being any Zambezi/Bulldozer based chips to test on, are some improved power characteristics. AMD has changed and improved the power specification, so it is a more efficient unit overall. This sounds like it is needed due to how the new Bulldozer chips handle turbo speeds and power gating. We should see some efficiency improvements with current CPUs, but these are in the range of a couple of watts. These results are measurable, but simply not meaningful for most users.
Two households, both alike in dignity...
At the end of the day, the reason that AMD decided to rebrand these chips as the 900 series is to make crystal clear what motherboards support the upcoming Bulldozer processors. While some motherboard manufacturers have enabled Bulldozer support through beta BIOS programs, it is still unclear how these boards will handle all of the features of that upcoming CPU. I am pretty sure most of the high end 890FX boards will work flawlessly with the new chips, but for quite a few users out there we probably should expect some confusion. AMD’s stance is that if a user wants a Bulldozer CPU, they should get a AMD 900 series of motherboards.
The most interesting update to this chipset is of course the SLI support. NVIDIA has finally relented, and allowed their manufacturing partners to include SLI support on the latest AMD chipset. It has been over two years now since NVIDIA launched the 900 series of AMD based chipsets. In the intervening time we have seen the introduction of SATA 6G and USB 3.0 on the AMD side, as well as some nice improvements in overclocking and power consumption. Unfortunately, the 980a boards currently available for AMD processors are just not that impressive when compared to what was available at the 890FX launch last year. Apparently with the specter of Bulldozer hanging over the market, and a pretty consistent call from reviewers and users alike, NVIDIA has given its blessing for multi-GPU goodness with their cards on the new 900 series of chipsets. There is one stipulation though; SLI is available only to those motherboard manufacturers who previously licensed the technology on their Intel P67 motherboards. So, we will see a handful of 990FX motherboards that do not officially support SLI. This is not the case for the two contenders we are looking at today.