I wouldn't go for none of the above.
I find it very annoying to have everything aligned to the left of the screen.
I would add a wrap container and center that to the screen. Add a darker BG color to your body to focus the attention to the center and there you have it.
This appears to be a CMS-like interface so it will be used by the "admins"
quite frequently to update their website/profile so it would be even more
annoying to have to go all the way to the far left side of the screen
all the time to change between pages.
You want to be able to keep everything an eye-movement away and keep a nice posture when using it.
Your first example forces you to keep your head twisted to the left and stress will build up in your neck leading to discomfort.
Your second example forces you to turn your head front-left-front every time you want to change tabs and that may get highly irritable and will prove to be unproductive.
Try to keep things together (without overcrowding).