My dear friend Diege,
You are not only new to sculpting, are you?
K stand for Kilo and is standard for 1000, like in Kilogramm, kilobyte…
324k = 324000
Have you ever build a toy plane?
You need some lead in front to get it into balance. It needs exactly this amount of lead, that is is balanced when you put two finger in centre of wings below. Then it will fly wonderfully.
Not that complicate but almost same it is with a computer.
Nomad shows you your free memory.
It should not be much below 1000 MB.
If your scene is bigger, if you have too much lead in your toy plane, it will not fly anymore. It will crashes straight down into the ground. The more lead - the more you are below 1000MB, the more likely it will happen.
Your plane is too heavy, you need to reduce the weight.
I want you to do the following:
Open a new scene.
Take the default sphere and think of a simple shape, an apple , I.e.
Now form it to an apple.
Now go to multi resolution and reduce the subdivisions till you still got the shape and the resolution still is enough not to make the little square shapes, called polygon, visible. You will see, you don’t need that much subdivisions for a simple apple shape.
You are in balance now.
Use only as much geometry resolution you need, start very low for blocking out your forms, switch on wireframe often, to see the resolution. A soft surface without details don’t need to be full of polygon.
Be careful with dynamic topology.
Dance with your imagination of the shape you have in your mind, and the lowest polygon resolution possible to realise it in Nomad.
You will see that you won’t need a tenth or less polygon (one square) and vertices ( the corner point of the square) like you use now.
Good luck and always keep your plane in balance, not too much lead please, otherwise = crash.