Stadia is a cloud gaming service by Google, where the games will be processed and rendered at the Google data center and stream to your device.
That means you don’t need expensive local processing like high-end PC or consoles to play games 4k at high settings.
Let’s get started with the important bits. Stadia will launch this year in 14 different countries included the US, UK, Canada.
So what is Stadia?
Basically, it’s a game streaming service that allows you to play the game directly through any chrome supported hardware that includes your PC.as long as you have Chrome installed, your Android phone your Chrome OS
tablet or laptop even things like Chromcast Ultra to play from your TV.
Performance
Last year when they tested it the performance of the project stream was limited to 1080p at 60fps when it launches
Stadia will offer up to 4K 60fps with HDR and they plan on allowing up to 8k at 120 FPS
in the future. Now I said that there was no console but google will offer the stadia controller which will connect via wifi to your network on top that it will directly be connected to the Google Network to avoid latency issues.

According to the presentation, you can stop gaming on one device and pick up on the next one seamlessly which is where this controller will shine.
Specification
Google did not give a complete specification but here are the some we know
CPU: Custom 2.7GHz hyper-threaded x86 CPU with AVX2 SIMD and 9.5MB L2+L3 cache
RAM: 16GB of RAM with up to 484GB/s of performance
Minimum 10 Mbps download / 1 Mbps upload
GPU: Custom AMD GPU with HBM2 memory and 56 compute units, capable of 10.7 teraflops
SSD cloud storage
35 Mbps download for ‘optimal’ 4K streaming
.
Google really working hard on AI and Gaming features
Yes indeed