## How Many SCV’s Per Mineral Node

The fastest way to mine minerals is to put three SCV’s on each mineral patch. Three SCV’s will maximize the percentage of time that the mineral patch is being utilized. Any more than 3 SCV’s will not produce any extra results, unless the mineral patch is far from the command center, as is the case when remote mining. The rest of this post explains why three SCV’s is fastest, and reports the results of an experiment where the mining rates were measured for different numbers of SCV’s.

Only one SCV can harvest a given mineral patch at once. If two SCV’s are sent to mine a mineral patch at once, one of the SCV’s will begin mining, while the other waits for the first to finish. Any time that a mineral patch is not being mined by an SCV, it is not being utilized, which is a wasted opportunity to increase the harvesting rate. For example, when a mineral patch has only one SCV dedicated to it, all of the time the one SCV is travelling to and from the command center is time that another SCV could be mining from the patch. Adding a second and third SCV will ensure that the mineral patch is constantly being utilized. But after adding the third SCV, the mineral patch will be mined constantly, and adding a fourth SCV will not increase the amount of time the patch is being utilized, and therefore will not increase the harvesting rate.

The following relation summarizes the above and is satisfied (evaluates to true) if and only a mineral patch is being constantly utilized:

$\text{travel time }\leq (\text{\# of SCV\'s}-1)*(\text{mining time})$

On the Steppes of War map, I timed the amount of time it took to mine 200 minerals using one, two, and three SCV’s. The first row in the table below shows the amount of time, in game seconds, it took to mine the minerals. The second and third rows show the mineral mining rates. The last row shows the amount the mining rate increases by adding each SCV.

#SCV’s 1 2 3
Time 329.25 164.625 115.0625
(minerals/second) 0.6074 1.2148 1.7381
(minerals/minute) 36.444 72.888 104.286

The values from the table are not going to be the same for every mineral node, depending on the distance from the command center to the node. Adding the third SCV didn’t produce the same increase in mineral rate as the first and second SCV, but it came close. In the future I’m going to look at the other mineral nodes to see how they compare.

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### 3 Responses to How Many SCV’s Per Mineral Node

1. Haploid says:

I like what you’re doing here. The measurements on the speed and acceleration of units is very informative.

I get somewhat different numbers from yours when I tried out the mining rate of an SCV. First, I read in this article on teamliquid by Piousflea, his calculations and measurements for the mining rate of an SCV. He comes up with 39-45 minerals per minute for the first two SCVs on a patch, and 102 minerals per minute for full saturation. That’s 0.65-0.75 minerals per second for the first two and 1.7 minerals per second for full saturation.

This agrees with my own measurements. I’ve set a single SCV to mine the nearest patch for 5 minutes. It mined 220 minerals, or 0.73 per second. A single SCV on the farthest patch netted 195 minerals in the same time, or 0.65 per second. Significantly higher than your numbers.

Of course, this was on normal speed. I used the ingame clock, so it wouldn’t have mattered anyway what game speed was used.

I am building up a site with sc2 calculators. You can find it at http://haploid.nl/sc2/. I would very much appreciate your feedback.

Again, kudos on your site. I think it can grow into a good source for sc2 math buffs, and I will definitely follow your work.

2. Thanks for the encouraging post. Your calculator is really sweet. I’ve actually wanted something exactly like that, but didn’t realize it existed. I’m surprised at how well put together it is. And thanks for the article from Piousflea, which is very high quality (quite better than mine).

The calculations I did were for the furthest mineral patch which would explain why my rate was on the low end of the range. But the rate I measured was below 0.65, which may just be something specific to the map, or it may be that his measurements were slightly imprecise because he was using a stop watch (or there’s a problem with my experiment) . I’ll post my method soon.

Thanks for the great comment and I’m definitely going to be seeing how I can play around with your calculator a bit more this weekend, because it really is well put together. I think it’ll be really good for evaluating build orders.