DocumentCode :
36641
Title :
A Reconfigurable SIMT Processor for Mobile Ray Tracing With Contention Reduction in Shared Memory
Author :
Kim, Han-Yee ; Kim, Yun-Jung ; Oh, J.-H. ; Kim, Lee-Sup
Author_Institution :
School of Electrical Engineering and Computer Science, MVLSI Lab. Dept. of EECS, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Republic of Korea
Volume :
60
Issue :
4
fYear :
2013
fDate :
Apr-13
Firstpage :
938
Lastpage :
950
Abstract :
In this paper, we present a reconfigurable SIMT multi-core processor with a shared memory for mobile ray tracing. The proposed processor addresses two issues of SIMT architecture: branch divergence of concurrently executed threads and contention in a shared memory. Performance degradation due to the branch divergence is reduced by dividing a wide SIMT datapath into several narrow SIMT cores that execute independent threads asynchronously. The contention in a shared memory caused by the multiple SIMT cores is alleviated by introducing a new time-division multiplexing (TDM) scheme using multi-phase clocks. The SIMT cores send their requests to a shared memory sequentially not concurrently by synchronizing the SIMT cores with multi-phase clocks to hide arbitration delays. The processor achieves the same datapath utilization as 4-wide SIMT which has been widely used by CPU-based ray tracers while its area remains 68% of the 4-wide SIMT. As a result, the performance normalized to area is improved by 26% compared to previous work with negligible overheads (2.6% for area and 1% for power consumption). The chip was fabricated in 90 nm CMOS technology, and it contains 2.3 M logic gates and 19.3 KB SRAM. It consumes 221 mW at 100 MHz with {\\rm Vdd}=1.2~{\\rm V} .
Keywords :
Clocks; Degradation; Instruction sets; Kernel; Multicore processing; Ray tracing; 3-D graphics; Branch divergence; SIMT; mobile multi-core processor; ray tracing; shared memory contention;
fLanguage :
English
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-8328
Type :
jour
DOI :
10.1109/TCSI.2012.2209302
Filename :
6289395
Link To Document :
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