less than 1 watt. 2 GHz operation and a TDP of 20 watts. L2 cache increased from 64k to 128k, with associativity increased from 16-way set associative in C3 to 32-way set associative in C7. VIA has stated the C7 bus is physically based upon the Pentium-M 479-pin packaging, but uses the proprietary VIA V4 bus for electrical signalling, instead of Intel’s AGTL+ Quad Pumped Bus, avoiding legal infringement. "Twin Turbo" technology, which consists of dual PLLs, one set at a high clock speed, and the other set at a lower speed. This allows the processor's clock frequency to be adjusted in a single processor cycle. Lower switching latency means that more aggressive regulation can be employed. Support for SSE2 and SSE3 extended instructions. NX bit in PAE mode that prevents buffer overflow software bugs from being exploitable by viruses or attackers. Hardware support for SHA-1 and SHA-256 hashing. Hardware based "Montgomery multiplier" supporting key sizes up to 32K for public-key cryptography. Design choices C7 Esther as an evolutionary step after C3 Nehemiah, in which VIA / Centaur followed their traditional approach of balancing performance against a constrained transistor / power budget. The cornerstone of the C3 series chips' design philosophy has been that even a relatively simple in-order scalar core can offer reasonable performance against a complex superscalar out-of-order core if supported by an efficient "front-end", i.e. prefetch, cache and branch prediction mechanisms. In the case of C7, the design team have focused on further streamlining the (front-end) of the chip, i.e. cache size, associativity and throughput as well as the prefetch system. At the same time no significant changes to the execution core (back-end) of the chip. The C7 successfully further closes the gap in performance with AMD / Intel chips, since clock speed is not thermally constrained. See also List of VIA C7 microprocessors List of VIA Eden microprocessors List of VIA microprocessors Intel Atom Netbook References Further reading External links Review of the EPIA EN15000 with VIA C7 Processor VIA C7 Processor VIA C7-M Processor Detailed Platform Analysis in RightMark Memory Analyzer. Part 12: VIA C7/C7-M Processors, translated in English http://www.cpushack.com/VIA.html https://www.pricenfees.com/digit-life-archives/via-cyrix-iii-samuel-2-600-667-mhz https://web.archive.org/web/20060615180950/http://www.sandpile.org/impl/c5xl.htm C7 Embedded microprocessors