Difference between revisions of "Blast processing"
From Sega Retro
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The term was used to refer to two things that gave the Mega Drive/Genesis a faster performance: | The term was used to refer to two things that gave the Mega Drive/Genesis a faster performance: | ||
| − | *The fact that the main CPU processor was clocked over two times faster than the one in its rival product, the [[wikipedia:Super Nintendo Entertainment System|SNES]]. Sega's [[Motorola 68000]] processor was clocked at 7.67 MHz, compared to the 3.58 MHz clock speed of Nintendo's Ricoh 5A22 processor. However, this was slightly misleading. This idea of simply comparing CPU clock rates to determine performance, regardless of other characteristics, is commonly known as the "[[wikipedia:Megahertz myth|megahertz myth]]". While Nintendo's 5A22 did run slower in clock cycles per second, it would put out more instructions per clock cycle, giving it a similar [[wikipedia:Instructions per second|MIPS]] (million instructions per second) performance to Sega's 68000. The 68000 did | + | *The fact that the main CPU processor was clocked over two times faster than the one in its rival product, the [[wikipedia:Super Nintendo Entertainment System|SNES]]. Sega's [[Motorola 68000]] processor was clocked at 7.67 MHz, compared to the 3.58 MHz clock speed of Nintendo's Ricoh 5A22 processor. However, this was slightly misleading. This idea of simply comparing CPU clock rates to determine performance, regardless of other characteristics, is commonly known as the "[[wikipedia:Megahertz myth|megahertz myth]]". While Nintendo's 5A22 did run slower in clock cycles per second, it would put out more instructions per clock cycle, giving it a similar [[wikipedia:Instructions per second|MIPS]] (million instructions per second) performance to Sega's 68000. The 68000's faster performance did not necessarily come from its higher clock rate, but from other advantages such as a faster memory bandwidth, more [[wikipedia:Processor register|registers]], [[32-bit era|32-bit]] instructions,{{ref|http://trixter.oldskool.org/2008/12/05/blast-processing-101/}} and shared [[wikipedia:Codebase|codebase]] with [[arcade]] games (where the 68000 saw widespread use). |
| − | *The fact that Sega's [[Yamaha]] YM7101 [[VDP]] graphics chipset had a [[wikipedia:DMA controller|DMA controller]] that could handle [[wikipedia:Direct memory access|DMA]] (direct memory access) operations at a faster speed than Nintendo's Ricoh PPU graphics chipset. While Sega's VDP had a DMA transfer rate of 7.2 KB per frame (432 KB per second), Nintendo's PPU had a DMA transfer rate of 5.72 KB per frame (343.2 KB per second). | + | *The fact that Sega's [[Yamaha]] YM7101 [[VDP]] graphics chipset had a [[wikipedia:DMA controller|DMA controller]] that could handle [[wikipedia:Direct memory access|DMA]] (direct memory access) operations at a faster speed than Nintendo's Ricoh PPU graphics chipset.{{ref|http://trixter.oldskool.org/2008/12/05/blast-processing-101/}} While Sega's VDP had a DMA transfer rate of 7.2 KB per frame (432 KB per second), Nintendo's PPU had a DMA transfer rate of 5.72 KB per frame (343.2 KB per second). The Mega Drive/Genesis also had a faster [[VRAM]] bandwidth of 204 bytes per scanline (52.2 KB per frame), compared to the SNES VRAM bandwidth of 170.5 bytes per scanline (43.6 KB per frame). The quicker data transfer rates are what really gave the Mega Drive/Genesis a faster performance over the SNES.{{ref|http://www.gamepilgrimage.com/content/sega-genesis-vs-super-nintendo}} |
==References== | ==References== | ||
Revision as of 22:16, 26 October 2015
Blast Processing was a marketing term coined by Sega to advertise the faster processing performance of the Mega Drive/Genesis. Sonic the Hedgehog 2 was the posterboy for this campaign, being faster than any other platform game at the time. The ad campaign featured commercials with races between two vehicles, with the SNES strapped to one and the Mega Drive strapped to the other.
The term was used to refer to two things that gave the Mega Drive/Genesis a faster performance:
- The fact that the main CPU processor was clocked over two times faster than the one in its rival product, the SNES. Sega's Motorola 68000 processor was clocked at 7.67 MHz, compared to the 3.58 MHz clock speed of Nintendo's Ricoh 5A22 processor. However, this was slightly misleading. This idea of simply comparing CPU clock rates to determine performance, regardless of other characteristics, is commonly known as the "megahertz myth". While Nintendo's 5A22 did run slower in clock cycles per second, it would put out more instructions per clock cycle, giving it a similar MIPS (million instructions per second) performance to Sega's 68000. The 68000's faster performance did not necessarily come from its higher clock rate, but from other advantages such as a faster memory bandwidth, more registers, 32-bit instructions,[1] and shared codebase with arcade games (where the 68000 saw widespread use).
- The fact that Sega's Yamaha YM7101 VDP graphics chipset had a DMA controller that could handle DMA (direct memory access) operations at a faster speed than Nintendo's Ricoh PPU graphics chipset.[1] While Sega's VDP had a DMA transfer rate of 7.2 KB per frame (432 KB per second), Nintendo's PPU had a DMA transfer rate of 5.72 KB per frame (343.2 KB per second). The Mega Drive/Genesis also had a faster VRAM bandwidth of 204 bytes per scanline (52.2 KB per frame), compared to the SNES VRAM bandwidth of 170.5 bytes per scanline (43.6 KB per frame). The quicker data transfer rates are what really gave the Mega Drive/Genesis a faster performance over the SNES.[2]
References
<mediaplayer>File:Blast Processing Commercial.flv</mediaplayer>
