CPU manufacturers always quote figures like "2 billion transistors!", I'm assuming cache is grouped into that which inflates it a lot, do you have any idea what the number is for all of a CPU but the cache? No specific model in mind

Not really. Transistor counts are basically bogus anyway. What really matters in a chip is power and area. Transistors obviously consume both, but a significant part of chip space is also the wires between the transistors, which also require area. The wires usually run over the transistors, but even so some parts of a chip have so many wires that you actually have spare space - you could add some more transistors for free! Of course they wouldn't be wired up to anything. However, you can take this approach to do some clever tricks. For example, caches usually have tons of tiny transistors and very few wires. But buses between functional units or between cores are almost all wires (and really long ones, too). So hey - why not put the caches UNDER the buses and use the space twice? And that's what people do, e.g. Knights Ferry/Corner/Xeon Phi did this - the inter-processor ring was laid over the L2$, so depending on which way you did the accounting you got one of them "for free". Also note that there's no thing thing as "a transistor". They're all different sizes. If they need to switch fast, or drive a long wire, or drive twenty other transistors, they usually need to be bigger. If they just need to talk to one transistor right beside them, then they can be smaller. Because of this, the "transistor count" metrics are usually just made up - they take the area of the chip, divide by the smallest transistor they can make, and there's you go - an impressively big number for marketing to use. So I suspect your real question is better phrased in terms of either area or power - and the answers will be different. Caches take up a lot of area, but consume relatively little power compared to a unit doing math. So a cache might take up 50% of the area of a chip, but only 20% of the power (make up numbers). You can get an idea of area from looking at die shots of common CPUs. The large regular caches are pretty easy to spot. Power is harder to measure yourself, but sometimes manufacturers talk about those in technical presentations. I can't really give an "average" answer - every core is different.