What's the polycount on each blade? Come to think of it, that doesn't matter. Building an entire lawn this way will kill just about anything, including dedicated workstations. Depending upon the scene you're trying to create, you'll probably have to take a few shortcuts. I believe "faking it" is the technical term. Use a few of those grass blades in the foreground as hero props, then fake the others in the distance with a mixture of transmapping and/or displacement (if you have P5). Years from now, when we all have desktop quantum computers, what you're attempting will be practical, but for now we have to compromise.