L3 20MB ! wow, it's the fastest processor I've ever seen !

these processors will be compatible with bigger screens and I think (if I'm not mistaken) it'll be compatible with the 4K if you've a graphics card that supports it.

however, the i7-4790K for most of people will be enough for them ! unless if they don't have it and they want to buy it, I'd recommend to add $40 and buy the i7-5820K. if they want to buy a new one !

Since you haven't mentioned your budget, I'd recommend ASUS N550JK-DS71T such a powerful laptop with responsible price! see this link

1. Go to Chrome browser settings chrome://settings

2. then go to Privacy

3. Then, from Privacy, click on Content settings button.

4. Now, on Cookies options, untick "Block third-party cookies and site data".

5. Then click done, and go back to Youtube and refresh the page using CTRL + F5 keys.

Problem Solved ;) ..