Figure 5. The GPU reconstruction is qualitatively identical to the CPU version.
(A) A high-resolution refinement of the Plasmodium falciparum 80S ribosome using single precision GPU arithmetic achieves a gold-standard Fourier shell correlation (FSC) indistinguishable from double precision CPU-only refinement (previously deposited as EMD-2660). The FSC of full reconstructions comparing the two methods shows their agreement far exceeds the recoverable signal (grey), and as shown in Figure 5—figure supplement 1 the variation in angle assignments match the differences between CPU runs with different random seeds. (B) Partial snapshots of the final reconstruction following post-processing, superimposed on PDB ID 3J79 (Wong et al., 2014).
Figure 5—figure supplement 1. The CPU and GPU implementations provide qualitatively identical distributions of image orientations.
For two CPU runs with different random seeds, 81% of images fall within 1, and for a GPU vs. CPU run 82%. Note that the probability of observing small angles vanishes since the number of potentially available points is proportional to the sine of the angle, which approaches zero for identical orientations. Both distributions were aligned against the reference refinement by fitting reconstructed models.