Zabbix 5.0 - percentile graph way off.

[TheImmortal]

Can someone please explain just HOW the percentile is calculated? Regardless of how it is, it makes no sense for me to have values such as:

http://prntscr.com/x6xtw4

or even worse, on graphs with two values:

http://prntscr.com/x6xvp1

This is more appropriate, yet still WAY off what's be a 95th percentile OF THE AVERAGE:

http://prntscr.com/x6xwyu

http://prntscr.com/x6xygn

Regardless of how I look at the graphs - as averages per 5, 60, 1440minutes, the values make no sense.

The graphs in question are based on the 'Linux OS by Zabbix Agent' template, for the network interface discovery: http://prntscr.com/x6y0k9

[NilsA]

These graphs look fine to me. A percentile essentially means where the value received lies in relation to all other values in the timespan you select. It does not matter how big the gaps are for percentiles. They work like "which % of all values is lower than this value?".
So in the first screenshot 288 is above the 95th percentile (it's the 100) because out of all the values on your screen it is the highest - higher than 100% of other values.

To get a better and more reliable 95th you just need to select more values.

[TheImmortal]

Care to explain a little bit more? First case scenario, in which way is 288 '95th percentile' of anything, considering (1) the last value is 256, (2) the avg is 265.6 and (3) the max is 288? I'd expect a 'percentile' to be the percentage of the average - is it defined as anything else anywhere?

Thank you.

[NilsA]

In this scenario, there are 5 values:
1.256
2.272
3.256
4.288
5.256

From this, we can rank the values like:
288 higher than 100% of other values: 100th percentile
272 higher than 60% of other values: 60th percentile
3-way tie for lowest value is 256

Percentiles are not percentages of an average. https://en.wikipedia.org/wiki/Percentile

[TheImmortal]

Based on the 5 values above, at https://www.calculatorsoup.com/calcu...calculator.php, I'm getting this http://prntscr.com/x7lhth - 284.4, which is something excel agrees to as well: http://prntscr.com/x7lrm7 - but not Zabbix.
WHY is this? :/ I apologize, might be redundant for these that understand it, but I'm afraid that (1) i don't really understand where the difference comes from and (2) am unsure as to how to get the 'percentile' that i'm looking for.