The latter is a 4-core machine with 8 HyperThreads. This doesn't actually matter to your price-performance metric but is worth mentioning because it's the reason why the Intel part performs so comparatively poorly. They're fast chips, they're just wildly uneconomical. If you wanted to compare equal core counts (c8i.4xlarge vs. c8g.2xlarge), then the Intel instance type wins on performance but the Graviton is 58% cheaper.