I say probably because I'm not factoring fantastical realities like higher dimensions. Why because we have no evidence they really exist. Also because if they do exist we would have no idea on how things would work there. So any ideas on how a computer would work would be futile.
So the only way we can look at this with any degree of certainty is if the universe that is simulating us would be like our universe. There becomes a lot of problems with how this could be accomplished. One of the problems with hardware is latency, you can see this when you see a live event on TV, what is happening is your viewing the past by a few seconds. In our universe everything is happening instantly. No latency means you would have to have near infinite processing power. Which would increase the needed electrical current near infinite. All the things you see would need to be processed graphically at such a high resolution and the amount of things would need to ne processed all at the same time makes the graphic processing power near infinite as well. This kind of reasoning follows for all the parts that are in a computer.
The software requirements would be enormous as well. You would need to porgram all the physics and how they work for each and every reaction that occur or they wouldn't be consistent. You would need to create logic and math for the behavior of all life, chemistry, physics, astrophyiscs. You could take shortcuts by making it look like so ething exists but it isn't really there. But when we point our telescopes to the sky we can tell the stars move and that they have planets that move around them. Which shows us that they aren't just a background picture. They are other solar systems that exists like ours. There are 100-500 billion stars in our galaxy then there our an unknown large amount of galaxies in a universe that we don't know how big it is.
On top of all that is there are multpile planes of existance in our reality the large(universe), smaller biosphere at the size we can observe with our senses, the microbiology you need to see with a microscope, the atomic, and the quatum. When you start to think of the scale of the amount that would need to be made it seems to be a smaller with the more that exists. Since there is near infinite universe makes me think it is near infinitely small chance that we are in a simulated universe.