Cassandra: concurrent queries for each partition or allow filtering

Question

Say I have the following Cassandra table:

CREATE TABLE experiment(
    bin text,
    x double,
    y double,
    PRIMARY KEY ((bin), x)
);

And I want to get the y values where x is greater than 10. Which one of the following two approaches would be the most efficient?

1. Enabling allow filtering:

   SELECT x, y FROM experiment WHERE x > 10 ALLOW FILTERING;
   

2. Omitting the need for allow filtering by first getting the list of partition keys and subsequently running multiple concurrent queries, one per partition.

   SELECT distinct bin FROM experiment;
   SELECT x, y FROM experiment WHERE bin = <bin> AND x > 10; //for each bin
   

Is there an alternative approach possible (with altered table design perhaps) that is more efficient?

Thanks in advance!

edit as an answer to a comment:

This is a constructed example. The real data will be a list of various sensor measurements:

time-stamp, subject-id, temperature, noise ...

The query we want to make is give me noise levels (over all measurements, on all subjects) where temperature is below 10 degrees. I don't mind switching to a different table design with a different partition strategy if that would benefit the query.