I imagine it’s possible to use the CPU from the modern consoles - but it’s really slow. As in, there isn’t really anything on the market right now in the PC world that runs that slow. They both use a custom 8-core “Jaguar” AMD chip which is basically an 8-core A-series CPU (without the integrated GPU) clocked down for longevity, to 1.6GHz.
This chip scored 1.041 in 3DMark '06, vs 1,197 from the prior generation’s A8-5600K email@example.comGHz. Yes, that’s just one metric but their desktop quad-core beats the console’s compute power with half the cores - and that’s in 2012. The reason I’m using that 5600K for my example is because it’s what I have in my TV-PC hooked up to a nice Panasonic plasma TV - it’s what I’m typing this on, right now. I use this computer for setups and Photoshop (when not gaming or watching shows) but for rendering it’s pathetically slow. It heats up rapidly and I cannot safely render with all four cores, even with an aftermarket cooler.
And that’s why those Jaguar chips in the consoles are clocked so low - they are very inefficient and the architecture is quite outdated and slow.
To sum up, there’s absolutely no reason to waste your time using the weak-sauce power of those consoles for rendering. Every real computer you can buy today will render faster, including most laptops. For the price of either console, you could buy a computer that renders many, many times faster - perhaps 16 or 32 times faster, or more. We’re not just talking about twice as fast or three times as fast.