VIA KM133 Socket-A Chipset: Final Battle of the Value Chipsetsby Anand Lal Shimpi on December 20, 2000 3:11 AM EST
- Posted in
The ProSavage Line
With VIA's acquisition of S3's graphics division, they gained the rights to use all of S3's graphics technology, the most recent contributions being the Savage4 and the Savage 2000 graphics cores. VIA's ProSavage line of chipsets all take advantage of these graphics cores by featuring a graphics engine derived from a combination of the Savage4 and the Savage 2000.
According to VIA, the ProSavage chipsets, which include the KM133, feature the Savage4's 3D core combined with the Savage 2000's 2D core making up what we like to call, the ProSavage graphics core. The reason for not including the Savage4's 2D core is because of performance concerns, and the reason for not going entirely with a Savage 2000 core is most likely of cost/heat concerns.
VIA has done nothing to increase the performance of the Savage4 or the Savage 2000 cores that are present in part on the KM133 North Bridge. Looking back at our original performance analysis of the Savage4, you’ll remember that we found that its performance was approximately equal to that of a default clock TNT2 (125/150) in 16-bit and slightly slower than a TNT2 Ultra in 32-bit performance. This is at lower resolutions, as you move to 800 x 600 and beyond, the performance drop was more pronounced and fell noticeably behind the TNT2.
With the ProSavage line of chipsets however, the 3D performance won’t be limited by the core, rather it will be severely crippled by a lack of memory bandwidth. As with all Unified Memory Architecture (UMA) systems the ProSavage core must share the same memory bandwidth as the rest of the motherboard. Meaning that with PC133 SDRAM, the 1.06GB/s of available peak memory bandwidth must be shared by the CPU, PCI devices, disk controllers, and the ProSavage video core as a means of getting to its frame buffer. Unfortunately this means that the ProSavage core will have much less available memory bandwidth than the standalone Savage4 which truly matters when it comes to 3D performance.
In terms of frame buffer size, the ProSavage core uses, by default, 8MB of system memory however that number can be changed by simply hopping into the BIOS and manipulating a setting. With the solution already being memory bandwidth limited, there will be very little need for more than an 8MB frame buffer setting since most of the time you will be restricted to very low resolutions (640 x 480 x 16) in order to sustain playable frame rates.