Where PC cooling is concerned, you can't get much more standard than copper - it's simply everywhere. Even if you're using an OEM box, chances are it at least has a copper base, and while it might not have many or any fins, your notebook will have a large copper heatpipe. So if copper is that effective, why not create a heatsink with a massive amount of it to keep a PC totally silent, and cool?
I've evaluated the possibilities of such a design while daydreaming in the past, but Germany's Silent PC have made it a reality - and I can honestly say, its real-world design looks nothing like what I've ever dreamed up.
Behold, the PC with copper mesh hat:
I've been unable to find real photos of this PC's internal design, but the website shows that all of the hot components, like the GPU and CPU, are placed right under the top of the chassis - which appears to be a massive copper base. With a direct connection like this, heat can be easily dissipated among this mesh, without the use of a fan. In a way, this design reminds me of Apple's latest Mac Pro, which connects the hottest components directly to a massive heatsink.
At the moment, this design is just a prototype. According to the wording on the website (which I had to rely on Google Translate for), it doesn't seem that the build above has actual components inside of it, and as such, no benchmarks / temperature data is able to be provided to us.
The Silent Power isn't a reality at this point; the folks behind it have been relying on crowd-funding support for it, and currently, just 14,395€ of the 45,500€ needed has been met. The company behind the PC is hoping that pre-orders for the PC will ramp up to make that possible. Currently, there are three models available, priced at 699, 769, and 1159 Euros. All include Windows 8.1, an Intel Core i7-4785T, at least 8GB of RAM, a 500GB SSD (how that's possible on the smallest two models, I'm not sure), an NVIDIA GeForce GTX 760, 4x USB 3.0, DVI, HDMI, DisplayPort, Audio I/O, 802.11ac, and Ethernet. Total weight of the PC is 1.35KG, and all three carry a two-year warranty.
For its very interesting design alone, I hope to see this PC become a reality. Even if the thought of keeping the copper mesh clean is a bit scary.