Specs are right on the Kickstarter page: It's a Jaguar based GCN APU with 2GB of dedicated RAM. OP, please provide the Kickstarter URL so we don't have to be guessing here
https://www.kickstarter.com/projects/smachteam/smach-z-the-first-handheld-steam-machine/
"We have been looking for a good balance between performance, cost and power efficiency, that will permit to play the majority of current games in Steam awesomely well. Take a look:
AMD embedded G-Series SoC (formerly codenamed "Steppe Eagle") with "Jaguar"-based CPU and GCN-based Radeon™ graphics with 2 GB of dedicated GPU RAM.
4 GB RAM memory (8 GB on PRO model)
64 GB* internal memory (128 GB on PRO model)
MicroSD Card Slot.
5-inch Touch screen with 1080p** resolution.
USB 3.0 type C
Configurable tactile gamepads.
HDMI video output connection.
Wi-Fi connectivity.
Bluetooth connectivity.
4G mobile network connectivity (PRO model only).
* Only if the Stretch Goal is achieved, otherwise: 32GB.
** Only if the Stretch Goal is achieved, otherwise: 720p."
Supposedly can handle such games as:
"Powerful enough to play any game on the market: Portal 2, DOTA, Left 4 Dead 2, Team Fortress 2, SOMA, Civilization V, Metro: Last Light Redux, Borderlands 2, The Witcher 2, ..."
This seems like a spurious claim given the Jaguar CPU involved but who knows as I was able to play a ton of games with the lowly 5350 APU some time ago.
I'm glad they're copying the Steam controller as it's much more well rounded than a traditional controller for a large Steam library.