Since Intel Corp, introduced the Pentium processor nearly three years ago. Intel and its two main rivals in the X86 market have unveiled seven additional processors and abandoned a numeric naming convention. The growing prevalence of multimedia features in desktop PCs is also driving chip manufacturers to take a look at optimizing CPU designs to improve multimedia performance and drive down PC costs. Processor names have become increasingly confusing since Intel”s competitors started vying for space in the 486 market with chips bearing -186-like names.
Starting with its clock-tripled 486 chip. which Intel has increased the name recognition of its chips by using trademarked names instead of numbers. while its competitors have continued to use numbers (often with the letter xi. Whether Cyrix’s 5×86, for example, is really a Pentium-class chip is debatable. but for corporate buyers. Performance rather than the chip’s name is the bottom line, which forms part of the Electronic Component Footprint Library.
Multimedia features may be the means by which processor vendors try to differentiate their chips. These chips are designed to lower the cost of multimedia PCs by using the CPU to perform such operations as driving the display or performing audio and video decompression, instead of having these tasks done by more costly graphics boards. sound cards, and MPEG boards.
When NexGen introduced its Nx686 chip at the Microprocessor Forum, the design included an integrated multimedia unit. details of which have not been disclosed. The Ll cache on the Cyrix 6×86 more closely resembles the cache structure of a 486 chip. Like a 486, the Cyrix processor has a single 16K-byte unified cache. which yields a higher hit rate than the Pentium’s split cache.
But because unified cache cannot be accessed twice per cycle to supply data and instructions to the processor core, the Cyrix chip should perform slower than the Pentium. External cache architectures also vary among the processors. The Pentium, the K5. and the 6×86 all use the system bus to connect to the cache and main memory on a system”s motherboard that is part of Electronic Component Footprint Library.
In the case of the Pentium, the maximum bus width and speed are 64 bits and 66MHz, respectively. In contrast, the Pentium Pro and the Nx586 use dedicated external cache buses. For both chips. the dedicated cache bus removes cache access from the busy system bus and thereby improves cache performance.
Mobile-ITX refers to the small form factor motherboards for x86-compatible processors, presented by VIA Technologies on December 1, 2009. Motherboard size is is 60mm × 60mm, however, it does not include I / O ports.
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