4gb (4 memory sticks) at 400Mhz on socket 939 MB -- JEDEC specifications ...

[Peter Arremann]

On Saturday 08 July 2006 14:43, Bryan J. Smith wrote:
<snip>
Thanks for the details - I had a hard time finding that... :-)

> As above.
>
> BTW, your greater concern than signaling is timing.  Slower timed DDR400
> DIMMs often cause more of an impact that faster timed DDR333 DIMMs.
>
> I personally use at least 2.5-3-3-6 for DDR400.
>
> If you're using 3-3-3-8 or worse for DDR400, you might as well run at
> DDR333.

Have you guys actually measured the impact of the memory speed? I'm running a 
few servers - dual 280s with 4GB ram each - that run queries against a 
smallisch in memory DB... this should be about as memory intensive as any 
application can get (unless you're running UMA graphics). Some systems have 
266Mhz memory - others 400. It looks like even in this setup, all I can see 
is less than 3% difference...

Peter.