The graphics processor
powering the Xabre 600 board is virtually identical to
what was featured on the preceding Xabre 400.
Mainly, the core consists of four rendering pipelines,
each equipped with two texture units. Running at
300MHz, SiS claims the core is capable of 30 million
polygons per second. Similarly, the board features
a theoretical pixel fill rate of 1.2Gigapixels per
second, and with all eight texture units fully utilized,
up to 2.4Gigatexels per second. SiS' .13-micron
manufacturing process is probably the most significant
contribution to the Xabre 600. Not only does the
smaller process facilitate faster operating frequencies,
but it also allows the Xabre 600 to run at 300MHz
without a loud cooling solution or an oversized heatsink.
SiS' reference board
includes the 301 companion chip, adding support for
TV-output (S-Video or composite), Digital Flat Panel
output, and a second CRT connector.
SiS used 64MB of Samsung
memory on the reference board we received. Though
the 2.8ns memory modules are theoretically capable of
350MHz, SiS operates the 128-bit memory bus
synchronously with the graphics processor, at 300MHz.
As mentioned, there is an overclocking utility that
provides the option to decouple the two clock
frequencies, but our overclocking attempts met with
mixed results. We managed to hit 330/350MHz with
SiS' own cooling solution and some thermal grease.
However, while some applications would demonstrate an
increase in performance, others would show the opposite.
Hardly reliable results in that department.
HotHardware Test Systems
SiS 648 for AGP
SiS Xabre 600 (64MB)
Driver Version: 3.07
GeForce4 MX 440-8X
RADEON 9000 Pro
Driver Version: Catalyst 2.4
Intel Pentium 4 3.06GHz
512MB PC3200 DDR400
IBM 30GB ATA-100
7200RPM Hard Drive
Words About The Benchmarks:
In setting up our test machines, we install Windows XP
on a formatted, FAT32 hard drive. After installing
the relevant drivers we disable system restore, all of
the graphical enhancements in Windows XP, and the
Automatic Update feature. The desktop on each test
bed is set to 1024x768, 32-bit color and a 85Hz refresh
Windows XP has been updated to Service Pack 1. Quake III
is at version 1.17 and we consequently
use the 'demo001' demo. 3D Mark 2001 SE has been
updated to Build 330.