Grafana displays data incorrectly

Please tell me, I have somehow strange Grafana works( I collect metrics on servers via Telegraph and output them with Grafana.
I look at the data for 24 hours and according to the metric disk write max = 2.16 Gb/s
And if I make an interval of drawing data not for one minute(as by default for 24 hours) and an interval of 10 seconds. Then for the same 24 hours maximum = 1.31 Gb/s
Why is that?
Maybe the problem is in the request:
SELECT the difference (men (“write_bytes”)) FROM “diskio” WHERE (“host” = ‘******’ And “name” = ‘sd1’) And Time Filter GROUP BY time(__interval) full (null)