Not exactly. Reduancy is designed into chip hardware not to account for cosmic rays striking the wrong trace, but for manufacturing defects. For example Nvidia

Not exactly. Reduancy is designed into chip hardware not to account for cosmic rays striking the wrong trace, but for manufacturing defects. For example Nvidia runs it's GTX 980 and GTX 970 production at the same time. The only difference is GTX970's can have up to 2 of their compute units non-functional. This is very commonly done in the industry. If you remember Phenom Dual, Tri, and Quadcores. Which were the same chip, just it was expected that only 5% of produced chips would be fully featured quad cores, the rest would be sold as other core counts. This was done with 27xx series i5, which were 34xx core i7's but with hyper threading disabled due to issues with yields on dye shrinks. If a single transistor fails, normally the whole thing dies.