On Sat, 10 Jan 2009 09:52:10 -0800 (PST), "larry moe 'n
curly" wrote:



Conor wrote:

In article 83981e4a-f306-432c-9e4b-d0ade341f4a2
@y1g2000pra.googlegroups.com, larry moe 'n curly says...

I have some motherboards designed for 4-6 SATA ports, but only 2 SATA
connectors were installed, and I'd like to add the missing connectors
plus any needed termination resistors.
Here's an example with an ECS GeForce 6100SM-M v. 1.0 motherboard:

http://farm4.static.flickr.com/3397/...b349938d_o.jpg

What are the values of the missing resistors? I thought that each
pair of SATA data lines needed one 100 ohm resistor between them, but
on this circuit board the resistors seem to be arranged differently.

You're assuming that the second SATA controller exists to utilize them.

Yes, and apparently the NVidia chipset does support additional SATA
devices. I don't know if the BIOS does, and it's possible that a
termination voltage source/sink isn't there fro the extra SATA
connectors.


Which chipsets do these boards have? AFAIK, nVidia 400,
405, 410 only support 2 SATA. 430 supports 4.

One thing we might need to consider is that if anyone were
to pull some stunt trying to save a fraction of a cent on
resistors, it'd be ECS/PCChips.

I don't have an nForce /4xx series board available to check
it, but checking an old A7N8X board that uses a Silicon
Image SATA controller, it has the SATA data pins coupled
directly to the chip inputs with a 2200pF ceramic chip
capacitor in series.

The picture linked above is a little high in contrast so
it's hard to tell but might those empty spots be
corresponding to capacitors on the adjacent used SATA spots?
Further, if you can trace these data lines to the chipset,
are there unused surface mount pads adjacent to it?