The outlier rule is based on the inter-quartile range (upper minus lower quartile). **Your data.** If you have so many RAM values at 4 and 8 that those are the lower and upper quartiles, respectively, then $\text{IQR} = 8 - 4 = 4,$ and any value above $Q_3 + 1.5(\text{IQR}) = 8 + 1.5(4) = 14$ will show as a high outlier. A small-sample version follows: x = c(2,2,4,4,4,4,4,4,8,8,8,8,8,8,8,8,16,16,16,24,24) summary(x) Min. 1st Qu. Median Mean 3rd Qu. Max. 2.000 4.000 8.000 8.952 8.000 24.000 IQR(x) [1] 4 boxplot(x, horizontal=T, col="skyblue2", pch=19) [![enter image description here][1]][1] If you take logs of your observations, a boxplot may be somewhat better suited as a graphical description. y = log2(x) summary(y) Min. 1st Qu. Median Mean 3rd Qu. Max. 1.000 2.000 3.000 2.818 3.000 4.585 IQR(y) [1] 1 boxplot(y, horizontal=T, col="skyblue2", pch=19) [![enter image description here][2]][2] **Outliers are common in exponential data.** It is a characteristic of samples from right-skewed distributions to show numerous 'outliers'. Below are boxplots for 20 samples of size $n = 100$ from an exponential distribution with mean 10. (About 99% of such samples will show at least one outlier.) m = 20; n = 100; x = rexp(m*n, .1); g = rep(1:20, each=100) boxplot(x ~ g, col="skyblue2", pch=19) [![enter image description here][3]][3] **Outliers are not rare in normal data.** Moreover, slightly more than half of normal samples of size $n = 100$ show at least one outlier. set.seed(606) nr.out = replicate(10^5, length(boxplot.stats(rnorm(100, 50, 7))$out)) mean(nr.out >= 1) [1] 0.52505 nr.out 0 1 2 3 4 5 6 7 0.47495 0.28644 0.13589 0.06059 0.02475 0.01010 0.00439 0.00171 8 9 10 11 12 13 0.00073 0.00027 0.00007 0.00006 0.00004 0.00001 Boxplots for 20 of the 100,000 normal samples from this simulation are shown below. [![enter image description here][4]][4] _Note:_ Applied to a normal _population_ the outlier rule would label observations more than about 2.7 SDs from the mean as outliers. _Samples_ do not precisely emulate populations, but normal tails have enough probability that it is not rare for moderately large samples to have some outliers. Boxplot 'outliers' are worth a second look, but they are by no means necessarily 'errors'. qnorm(.75) + 1.5*diff(qnorm(c(.25,.75))) [1] 2.697959 2*pnorm(-2.7) [1] 0.006933948 [1]: https://i.sstatic.net/E7CNt.png [2]: https://i.sstatic.net/F5tph.png [3]: https://i.sstatic.net/iUHZR.png [4]: https://i.sstatic.net/TNkYd.png