Performance of parallel execution time of query to flex table

When you run a parallel query to flex table, At this time, all processing is slow.

For example, two queries execute,
1 query about 100sec,
2 queries about 200sec/query, Much as both.
At this time, there is a margin in cpu utilization.

and

When to parallel processing of a single query to flextable can be slow,

EXECUTIONPARALLELISM=30 180sec CPU Usage 3000%
EXECUTIONPARALLELISM=5 95sec CPU Usage 500%
EXECUTIONPARALLELISM=1 58sec CPU Usage 100%

EXECUTIONPARALLELISM=1 is fastest and CPU usage is the lowest!


Test environment spec
5node cluster(cpu 32, mem 128GB, HDD 12TB)