I have an "early 2006" iMac, model iMac4,1. What's odd is that OS X says the CPU is a Core Duo but Intel's documentation says it is a Core Solo. I'm trying to figure out what I actually have. Here's how it breaks down: System Profiler says it's an Intel Core Duo @ 1.83 GHz, 1 processor with 2 cores. MacCPUID (Intel's utility), says it is a model 1400 @ 1.83 GHZ, Family 6, Model 14, Stepping 8. However, Intel's site doesn't list a Core Duo model 1400. It does list a Core Duo T2400 which seems to fit the description: http://ark.intel.com/ProductCollection.aspx?familyId=22731 And Intel's site does list a Core Solo model 1400: http://ark.intel.com/ProductCollection.aspx?familyId=18995 I'm pretty sure I don't have a Core Solo, because Activity Monitor shows two CPUs. Can anyone shed some light on what's going on here? It seems likely that this iMac is using a T2400 Core Duo, but that doesn't explain why Intel's own utility would misidentify it as a 1400. I'm thinking of upgrading the CPU and so I'm trying to figure out what is currently in there and what features it has. Thanks!