Under the hood: MotorStorm “uses 15-20% of available SPU resource”

Talking to Beyond3D about their baby MotorStorm, technical director Scott Kirkland stripped the hood off the game and revealed how many of the PS3 gears MotorStorm runs on. In SPU usage terms, he says the game “only uses between 15 and 20 percent of available SPU resource.”

On how it stacks up with an earlier assertion that MotorStorm uses all of PS3’s SPUs, we can infer that the game runs across all of the Cell Processor‘s processing units, but it still all averages out to 15-20% of total available processing resources. After all, Scott enumerates exactly what runs on those SPUs:

• Havok physics.
• Determination of object visibility.
• Concatenation of hierarchies.
• Billboard object culling and vertex buffer creation.
• Updating of particles and vertex buffer creation.
• Updating of vehicle dynamics.
• Updating of vehicle suspension constraints.
• Audio (MultiStream).
• Video decoding.

Not on that list are rendering MotorStorm‘s dirty graphics: “We donÂ’t use the CellÂ’s SPUs in this way at the moment.  All of our lighting and transformation work is done in the RSXÂ’s pixel and vertex shaders.” In the future, however, Scott believes that “cooperative rendering” between the RSX and SPUs “will become far more widespread”… given enough experience, of course.

That leaves how a future MotorStorm could look like open to the imagination.

Talking to Beyond3D about their baby MotorStorm, technical director Scott Kirkland stripped the hood off the game and revealed how many of the PS3 gears MotorStorm runs on. In SPU usage terms, he says the game “only uses between 15 and 20 percent of available SPU resource.”

On how it stacks up with an earlier assertion that MotorStorm uses all of PS3’s SPUs, we can infer that the game runs across all of the Cell Processor‘s processing units, but it still all averages out to 15-20% of total available processing resources. After all, Scott enumerates exactly what runs on those SPUs:

• Havok physics.
• Determination of object visibility.
• Concatenation of hierarchies.
• Billboard object culling and vertex buffer creation.
• Updating of particles and vertex buffer creation.
• Updating of vehicle dynamics.
• Updating of vehicle suspension constraints.
• Audio (MultiStream).
• Video decoding.

Not on that list are rendering MotorStorm‘s dirty graphics: “We donÂ’t use the CellÂ’s SPUs in this way at the moment.  All of our lighting and transformation work is done in the RSXÂ’s pixel and vertex shaders.” In the future, however, Scott believes that “cooperative rendering” between the RSX and SPUs “will become far more widespread”… given enough experience, of course.

That leaves how a future MotorStorm could look like open to the imagination.