Difference between revisions of "Blast processing"
From Sega Retro
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*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|Super NES]]. 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 the main CPU processor was clocked over two times faster than the one in its rival product, the [[wikipedia:Super Nintendo Entertainment System|Super NES]]. 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 the Sega Mega Drive's [[Yamaha]] YM7101 [[VDP]] graphics chipset had a powerful [[wikipedia:DMA controller|DMA controller]] that could handle [[wikipedia:Direct memory access|DMA]] (direct memory access) operations at a faster speed than the Super Nintendo's Ricoh PPU graphics chipset.{{ref|http://trixter.oldskool.org/2008/12/05/blast-processing-101/}} The Mega Drive/Genesis could write to [[VRAM]] during active display and [[wikipedia:Vertical blanking interval|VBlank]],{{ref|http://emu-docs.org/Genesis/sega2f.htm}} and had a faster VRAM bandwidth than the SNES. The quicker transfer rates and bandwidth gave the Mega Drive/Genesis a faster performance over the SNES.{{ref|http://www.gamepilgrimage.com/content/sega-genesis-vs-super-nintendo}} This included a higher [[fillrate]], higher gameplay resolution, faster scrolling, high frame-rate with many moving objects on screen, and capabilities such as rendering a [[wikipedia:Bitmap|bitmap]] | + | *The fact that the Sega Mega Drive's [[Yamaha]] YM7101 [[VDP]] graphics chipset had a powerful [[wikipedia:DMA controller|DMA controller]] that could handle [[wikipedia:Direct memory access|DMA]] (direct memory access) operations at a faster speed than the Super Nintendo's Ricoh PPU graphics chipset.{{ref|http://trixter.oldskool.org/2008/12/05/blast-processing-101/}} The Mega Drive/Genesis could write to [[VRAM]] during active display and [[wikipedia:Vertical blanking interval|VBlank]],{{ref|http://emu-docs.org/Genesis/sega2f.htm}} and had a faster VRAM bandwidth than the SNES. The quicker transfer rates and bandwidth gave the Mega Drive/Genesis a faster performance over the SNES.{{ref|http://www.gamepilgrimage.com/content/sega-genesis-vs-super-nintendo}} This included a higher [[fillrate]], higher gameplay resolution, faster scrolling, high frame-rate with many moving objects on screen, and programming capabilities such as mid-frame palette swaps (per scanline), direct color mode (increasing colors displayed on screen), rendering a [[wikipedia:Bitmap|bitmap]], and processing 3D polygons with stock hardware (without needing enhancement chips). For more details on the Mega Drive's DMA capabilities, see [[Sega Mega Drive#Blast Processing|Sega Mega Drive: Blast Processing]]. |
==References== | ==References== | ||
Revision as of 22:52, 5 September 2016
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 Super NES. 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 the Sega Mega Drive's Yamaha YM7101 VDP graphics chipset had a powerful DMA controller that could handle DMA (direct memory access) operations at a faster speed than the Super Nintendo's Ricoh PPU graphics chipset.[1] The Mega Drive/Genesis could write to VRAM during active display and VBlank,[2] and had a faster VRAM bandwidth than the SNES. The quicker transfer rates and bandwidth gave the Mega Drive/Genesis a faster performance over the SNES.[3] This included a higher fillrate, higher gameplay resolution, faster scrolling, high frame-rate with many moving objects on screen, and programming capabilities such as mid-frame palette swaps (per scanline), direct color mode (increasing colors displayed on screen), rendering a bitmap, and processing 3D polygons with stock hardware (without needing enhancement chips). For more details on the Mega Drive's DMA capabilities, see Sega Mega Drive: Blast Processing.
References
<mediaplayer>File:Blast Processing Commercial.flv</mediaplayer>
