Games at Bolton CELL (diagrams from IBM) Andrew Williams

Games at Bolton CELL partners  Sony, IBM, Toshiba  We all know why Sony wants the CELL –What is IBM’s angle? –What about Toshiba – what do they want out of the CELL?

Games at Bolton CELL chip image What is this?

Games at Bolton PPU  Power Processing Unit –Where might you have expected to find one of these a couple of years ago?

Games at Bolton SPE questions  Each SPE has bit registers –What is a register anyway? Name an example from an x86 compatible CPU –How many bytes per register? –128-bits seems a lot (modern desktop CPUs have 64-bit registers) Why does it need 128-bit registers?

Games at Bolton This is an SPE: 256K?? What the….?!

Games at Bolton Multiplying a matrix by a vertex void Matrix4f::multiply(const Vector4f vec4f, Vector4f *resultVector) { float *vD = (float *)vec4f.data; // Just for convenience resultVector->data[0] = data[0]*vD[0] + data[1]*vD[1] + data[2]*vD[2] + data[3]*vD[3]; resultVector->data[1] = data[4]*vD[0] + data[5]*vD[1] + data[6]*vD[2] + data[7]*vD[3]; resultVector->data[2] = data[8]*vD[0] + data[9]*vD[1] + data[10]*vD[2] + data[11]*vD[3]; resultVector->data[3] = data[12]*vD[0] + data[13]*vD[1] + data[14]*vD[2] + data[15]*vD[3]; };

Games at Bolton SPE FP performance  A CELL can handle 250GFLOPS as long as you’re happy with SP  Translate that into English –What (according to IBM) is the likely performance penalty if you really want DP FP?

Games at Bolton EIB

Games at Bolton EIB questions  What is the clock speed of the PS3 CELL?  What is the clock speed of the EIB?  How is the theoretical maximum bandwidth calculated?  How many concentric data pathways (rings) are there in the EIB?  How many data transfers can run concurrently on each ring?

Games at Bolton EIB questions (continued)  Give examples of the sorts of activity that could reduce the bandwidth of the EIB

Games at Bolton RSX  What is the RSX?  Who developed the RSX?  Which consumer PC product is most like the RSX?  What does the design of the RSX say about the work that the SPEs are likely to be doing?

Games at Bolton PS3 and Backwards Compatibility  PS2 is the biggest selling home console  PS2 has the biggest library of games  Microsoft’s XBOX  XBOX360 compatibility issues  All good reasons why Sony would want to ensure that the PS3 can run PS2 games

Games at Bolton PS3 and Backwards Compatibility  American PS3 motherboard includes a chip labelled EE/GS EE/GS What does EE/GS mean?

Games at Bolton PS3 and Backwards Compatibility  On the European model that chip is absent: ZOMG!!!

Games at Bolton PS3 and the PS2 – What Gives?  If the EE/GS isn’t there, what happens to backwards compatibility in European (and later American) versions? –How is it done? –What are the advantages and disadvantages?