Re: Memory question

M. N. wrote:
> I just purchased a Tyan S2098 mobo that uses the Intel 845GL chipset. The
> manual states 400 MHz FSB support. But the memory should be PC2100 DDR
> memory which corresponds to DDR266. Why isn't faster memory supported --
> given that the FSB is 400Mhz?
>

The characteristics are set by the chipset. Download the datasheet
to get more information.

http://www.intel.com/design/chipsets...hts/290746.htm

On PDF page 73, the GMCH configuration register controls the
memory clock. Basically, there is a two bit wide field in the
register, that selects one of four possible options. In typical
Intel style, two of the options are not documented. The two that
are, correspond to DDR200 or DDR266. So basically, Tyan is
adhering to the documented settings and capabilities of
the chipset.

Your board should be quite stable, with the conservative
choices of FSB400 and DDR266.

The record for the 845 family, is an overclocked 845PE, which
can drive only one stick of RAM at DDR400. If you plug in
two sticks, it would crash. So while the memory bus can be
run at higher speed, it isn't all that stable. The board
that supported that option, was an Asus P4PE.

http://web.archive.org/web/200310032...rt/fsb800.aspx

Paul