Table 2.

Single-precision GPU CS MRI reconstruction times for test images ranging from 16² to 8192² with and without CPU multithreading. Effective speedup is the multicore CPU time relative to the GPU time.

Square	CPU time (s)		GPU	Effective
image size	1 Core	6 Cores	time (s)	speedup
16	0.011	0.011	0.060	0.18
32	0.016	0.017	0.060	0.28
64	0.038	0.046	0.063	0.73
128	0.13	0.099	0.061	1.62
256	0.49	0.28	0.066	4.24
512	2.0	1.1	0.12	9.17
1024	8.4	3.4	0.34	10.00
2048	35	14	1.3	10.77
4096	160	68	8.3	8.19
8192	670	270	140	1.93