Photoshop Ram Requirements
Photoshop by default does not require a lot of RAM, however when working with larger files or files with a larger bit depth or effects like the Liquify Tool, it can play an important role in performance. If you intend to use any of the video editing capabilities of Photoshop this will also be true. I recommend not working in Photoshop with less than 4GB of Ram. If you work in print production, I recommend 8GB of Ram, particularly if you are working with a lot of layers.
Photoshop Processor Requirements
Photoshop CC like Photoshop CS6 has made use of the Mercury Performance engine and is more streamlined than ever. That being said you should still be mindful that saving larger files with multiple layers, effects and filters as well as doing batch processing of high quality photographs will require intense processor usage. I recommend that when purchasing a laptop that you keep this in mind and purchase a Dual Core laptop though Quad Core is ideal, also they should have a core speed of atleast 2GHz. If you are purchasing an Intel chipset computer, get the I5 rather than the I3.
Advanced Photoshop/Adobe Recommendations
If you are going to be working in 3D or using some of the more resource intensive features of any Adobe app.lication I recommend the following:
A multi-hard drive setup: Many laptops today can hold up to 2 hard drives 3, if you replace the optical drive with a SSD. This is ideal as you can now use a completely separate Drive as a Scratch Disk for improved Photoshop performance
16GB of Ram. While most laptops allow for a maximum of 8GB of Ram there are some more expensive options that allow as much as 16GB of Ram. This is particularly useful in Quad and Octo Core laptops since ideally you would want 4GB to each core as a ratio.
Quad Core or Better Processors at 2.4GHz or more. Again typically this is not something that will come on a laptop that you can buy standard over the counter, however this is for your ultimate mobile work station if you are doing print, animation or video and can’t afford to slow down.
An External Hard drive to use as a Scratch Disk in addition to storage.
http://robertoblake.com/blog/2013/06/thoughts-on-buying-a-photoshop-cc-laptop/