No, they don't always achieve the same results but there is a lot of engineering dedicated to correct the errors. You can find academic papers on the subject o

No, they don't always achieve the same results but there is a lot of engineering dedicated to correct the errors. You can find academic papers on the subject of GPGPU soft errors around 5 years ago when people started doing general purpose computation on graphics processors. GPU's did not dedicate as much logic to error correction because it doesn't matter as much for real time graphics.