jmke

AMD’s Graphics Product Group finished its transition from the Radeon HD 4000 to 5000 generation as the Radeon HD 5830 closed the last gap between the Radeon HD 5770 and Radeon HD 5830 and made the whole series of AMD’s DirectX 11 compatibles complete. A junior Radeon 5800 series model had indeed been lacking as there had been a large price gap between the earlier released Radeon HD 5770 (below $160) and Radeon HD 5850 ($399). It could be filled in by either a tuned-up version of Radeon HD 5770 or a cut-down variant of Radeon HD 5850. AMD chose the latter option and based its Radeon HD 5830 on the RV870 Cypress core, the same core as in the Radeon HD 5850 but with a cut-down configuration.

This is a wise solution considering that the Cypress itself is a highly complex chip incorporating over 2 billion transistors. Despite the polished-off tech process, there is going to be a large share of defective chips which, however, might work just fine if the defective subunits were turned off. This turning off of defective subunits helps the manufacturer put such chips to good and profitable use rather than scrap them altogether. That’s a standard practice among GPU makers. In fact, the Radeon HD 5850 itself has a small part of its shader and texture-mapping processors turned off. As for the Radeon HD 5830, there are 480 ALUs, 24 TMUs and 16 (out of 32) raster back-ends disabled in its RV870 processor.



http://www.xbitlabs.com/articles/vid...on-hd5830.html

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