As mentioned in the comments, your conclusion is backwards (haven't checked the validity of your calculations. I am not sure what you mean by 1/10 of our speed). We know from the twin paradox that the traveling twin is the twin who has aged less when they return to Earth due to changing inertial reference frames during the trip.
Therefore, if you wanted a calculation done "quickly" you would have to be the one who hops on a spaceship, goes on a long journey, turns around, and then comes back.
I suppose there is nothing wrong with this in theory. I guess you would need to have sufficient justification that the use of resources to do this trip outweighs the time it would take to just wait on Earth.
Or you could go hang out by a black hole for a little bit.
Based on your edits I think I understand what is going on here. You are taking "the universe" to be some "absolute reference frame", and you are thinking that the Earth has some speed relative to this frame. Then you send the computer at a speed relative to the universe that is less than the Earth's speed relative to the universe. So you say that the time dilation of the Earth relative to the universe is then greater than the time dilation of the computer relative to the universe, so we get faster calculations relative to us.
This is not how relativity works. There is no absolute reference frame that has the "true time", and there is no moving relative to this absolute reference frame that changes your own experience of time. All that matters in this scenario is the relativity between you and the computer. This is why saying "the computer is at 1/10 our speed" is meaningless. The computer can only have some speed relative to us.