Intel 815 - Manual (Page 21)

Introduction
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Intel
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815 Chipset Platform Design Guide 21
1.3.3 Platform Initiatives
1.3.3.1 Universal Socket 370 Design
The Intel 815 chipset platform for use with the Universal Socket 370 allows systems designers to
build one system that is compatible with the Pentium III processor (CPUID=068xh), Celeron
processor (CPUID=068xh), and future 0.13 micron socket 370 processors. When implemented,
the Intel 815 chipset platform for use with the Universal Socket 370 can detect which processor is
present in the socket and function accordingly.
1.3.3.2 PC 133
The Intel PC133 initiative provides the memory bandwidth necessary to obtain high performance
from the processor and AGP graphics controllers. The platform’s SDRAM interface supports
100 MHz and 133 MHz operations. The latter delivers 1.066 GB/s of theoretical memory
bandwidth compared with the 800-MB/s theoretical memory bandwidth of 100 MHz SDRAM
systems.
1.3.3.3 Accelerated Hub Architecture Interface
As I/O speeds increase, the demand placed on the PCI bus by the I/O bridge becomes significant.
With the addition of AC’97 and Ultra ATA/66, coupled with the existing USB, I/O requirements
could affect PCI bus performance. The chipset platform’s accelerated hub architecture ensures
that the I/O subsystem, both PCI and integrated I/O features (IDE, AC’97, USB), receives
adequate bandwidth. By placing the I/O bridge on the accelerated hub architecture interface
instead of PCI, I/O functions integrated into the ICH and the PCI peripherals are ensured the
bandwidth necessary for peak performance.
1.3.3.4 Internet Streaming SIMD Extensions
The Pentium III processor (CPUID = 068xh) provides 70 new SIMD (single-instruction, multiple-
data) instructions. The new extensions are floating-point SIMD extensions. Intel
®
MMX™
technology provides integer SIMD instructions. The Internet Streaming SIMD extensions
complement the MMX technology SIMD instructions and provide a performance boost to floating-
point-intensive 3D applications.
1.3.3.5 AGP 2.0
The AGP 2.0 interface allows graphics controllers to access main memory at more than 1 GB/s,
which is twice the bandwidth of previous AGP platforms. AGP 2.0 provides the infrastructure
necessary for photorealistic 3D. In conjunction with the Internet Streaming SIMD Extensions,
AGP 2.0 delivers the next level of 3D graphics performance.