Here is a shot of the Dram configuration
settings in the bios.
The max mem clock setting is actually your
FSB/Memory divider. The settings available are "100Mhz", "133Mhz", "166Mhz"
and "200Mhz", which corresponds to 1/2, 3/2, 5/4 and 1/1 dividers
With this board, and probably most of the K8
boards, there are many memory timings/settings to tweak as seen from the
options. This Ali board is a little sensitive towards these settings and I had
to go through many different combinations before it would work properly at
200Mhz memory speed with the Corsair XMS 3200.
Here are the memory settings used in the
testing. This is the fastest possible for our setup. The bios used is dated
- Cas latency: 2.0
- Row cycle time: 8
- Row refresh: 10
- Ras-Cas delay: 3
- Row-Row delay: 2
- Min Ras Active time: 13
- Row precharge: 2
- Write Recovery: 2
- Write to Read: 1
- Read to Write: 1
- Refresh period: 1 x 2064
Under the HyperTransport configuration options,
you get to adjust the CPU to Northbridge frequency and width. And also the
data access frequency and width between Northbridge and Southbridge.
We use the maximum settings possible for our
tests, which is
- Hammer to M1687 Frequency: 800Mhz
- Hammer to M1687 Width: 16 bit
- M1687 to M1563 HTT Frequency: 400Mhz-400Mhz
- M1687 to M1563 HTT Width: 8 bit
- M1687/M1563 HTT Tristate: Enabled
In the Frequency/voltage control screen we only
had the option to change FSB as this is an engineering sample. The FSB can be
adjusted from 170 Mhz to 230 Mhz.
With no voltage adjustments available, I was
able to overclock the FSB to 220 Mhz with stability to run 3D benchmarks. With
some more voltage, I’m sure I can hit higher. I had to lower Row-Row delay to
3T after 215 Mhz.
We can see that the Athlon 64/Ali combo scales
very well as we go up in Mhz, from 44s Super pi run to 40s Super pi run by
just upping the speed by 200 Mhz. This is equivalent to 2s for every 100 Mhz.
The Ali reference board, although an early
engineering sample, already shows some serious performance potential when
coupled with the Athlon 64. The overclockability is also there as I was able
to go up to 220 Mhz FSB without any voltage adjustments. The retail boards by
manufacturers will probably have more voltage adjustments. It is a little
sensitive towards memory settings so you might need to play around with the
settings a little.