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Re: gEDA-user: trace calculation

My experience at ~1GHz (2Gbps FibreChannel) is that the difference between round corners and 45 degree pairs is small, but if you're pushing the limits like we were, it can be significant.  The biggest problem we had with round corners was a CAD package that generated gerbers with line segments for curves that ended up shorting the differential pairs!
 
--DLM
 
-------------- Original message --------------
From: Larry Doolittle <ldoolitt@xxxxxxxxxxxxxxx>
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On Thu, Jan 05, 2006 at 04:27:20PM -0500, DJ Delorie wrote:
> 
> On my AMD motherboard, the bus traces have s-shaped wiggles in them to
> keep the lengths all the same.  Rounded corners, too.

The rounded corners are probably overkill.  Those traces have
to carry 3.2 GB/s, IIRC.  So response up to ~10 GHz matters,
and the relevant distance scale is 3 cm.  Anything smaller
than 3 cm only shows up in its net capacitance, inductance,
and time delay.

    - Larry

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