[coreboot] seeking AMD 990FX / SB950 documentation

[David Griffith]

On Wed, 18 Jul 2012, Mark Nelson wrote:

>> >     Would someone please point out where I can get documentation on the 
>> AMD 990FX /
>> >     SB950 north and south bridges? The 800 series stuff is at 
>> support.amd.com, but
>> >     not these.
>> 
>> Hi
>> 
>> 
>> Yes I have same question, but maybe AMD folks here could sched some light 
>> on documentation release plan.
>> 
>
> I believe the 990FX and the SB950 are essentially the same thing as the 890FX 
> and the SB850 - the same silicon. AMD just transitioned to the 900 series 
> numbering to easily allow consumers to tell whether a motherboard has an AM3+ 
> or an AM2 socket on there, and so whether it supports their Bulldozer family 
> of CPUs or not.
>
> From the Tech Report:
> "Led by the 990FX, this core-logic family is new in name only. The 990FX 
> consists of the same north- and south-bridge components as its 890FX 
> predecessor, and those chips continue to be manufactured by TSMC using a 
> 65-nm fabrication process."
>
> From tom's hardware:
> "The 990FX chipset employs the same silicon as 890FX.
> ...
> According to AMD, it’s incrementing the platform name to clarify 
> compatibility with Bulldozer-based processors. When you see a board that 
> centers on 990FX, the company wants you to know that its upcoming AM3+ CPUs 
> are drop-in-compatible (again, 990FX-based boards will also take existing AM3 
> chips)."
>
> From Hardware Secrets:
> "The AMD 990FX chipset is basically an AMD 890FX chipset with a new name, but 
> supporting the higher HyperTransport 3.0 speeds that weren’t used before and 
> that will be supported by the “Bulldozer” processors.
> The AMD 990FX chipset is targeted to the new socket AM3+ platform, while the 
> 890FX chipset is targeted to the socket AM3 platform. This way, AMD is 
> providing an easy way to identify the platform through the chipset name. 
> Socket AM3+ motherboards support the forthcoming AMD CPUs based on the new 
> “Bulldozer” architecture. So, even though the chipset is basically the same, 
> 890FX motherboards won’t support this new generation of AMD processors."

There must be something new about the 990FX because there's support in 
there for nVidia SLI.  Earlier chipsets don't do SLI.  Look here: 
http://blogs.nvidia.com/2011/04/you-asked-for-it-you-got-it-sli-for-amd/

-- 
David Griffith
dave at 661.org