Basically optimizing in general. Maybe your mesh is too dense, so try getting the poly count down, deleting a few loops here and there, because maybe you have the Subsuf in level 4 and cutting it down to level 2 gives you the same result and the poly count would drop a lot in conjunction with getting rid of a few loops. Perhaps you’re using 8K textures, maybe drop them to 4K or even 2K if your computer can’t handle it. Maybe you have lots of light bounces, cut those down. And if still your render wont start and you’re running out of memory, then you can try linking in your assets to another scene, that saves a lot of memory. And if you still have to optimize further, render make your render in render layers. And if still all those optimizations is not enough, then yeah you have to buy a new computer probably with much more better specs.
