FreeBSD 5.3 installation on Asus K8V-D impossible?

[David O'Brien]

On Mon, Feb 28, 2005 at 09:33:19AM +0100, Roman Neuhauser wrote:
> # obrien at freebsd.org / 2005-02-28 00:25:23 -0800:
> > On Mon, Feb 28, 2005 at 08:39:54AM +0100, Roman Neuhauser wrote:
> > >     What memory did you have in the box? I've had the same problem with
> > >     K8T Neo-FIS2R and 3x Corsair CMX512-3200C2. The board only works
> > >     with a narrow selection of 400MHz modules. :(
> > 
> > Actually I would read the mobo *and* AMD docs very, very carefully.
> > Using 3x DDR400 (PC3200) DIMM's is out of the JEDEC spec, IIRC.  I stick
> > to DDR333 (PC2700) memory as its easy to find CL2.5 DIMMs, but most
> > DDR400 is CL3.0.  So the end performance in the BW increase is mostly a
> > wash; and I avoid the electrical loading issues of the faster memory bus.
> 
>     I'll admit I'm not an expert on hardware, can you point out what's
>     wrong with the configuration (3 double-sided 400MHz modules)?

It is an electrical load issue.  The non-buffered memory controller can
only drive 2x DDR400 loads.  A 939-pin dual-channel memory controller
Athlon64 can drive 4x DDR400 loads.  An Opteron can drive more due to
being buffered/registered memory.
 
-- 
-- David  (obrien at FreeBSD.org)