Sparql extremely slow with this query and content

[rchateauneu]

This query takes dozen of minutes, but less than one second with Protégé.

        prefix cim:  <http://www.primhillcomputers.com/ontology/survol#>
        prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#>
        select ?my_dir_name3
        where {
        ?my_dir1 rdf:type cim:Win32_Directory .
        ?my_dir1 cim:Name "C:" .
        ?my_assoc_dir1 rdf:type cim:Win32_SubDirectory .
        ?my_assoc_dir1 cim:GroupComponent ?my_dir1 .
        ?my_assoc_dir1 cim:PartComponent ?my_dir2 .
        ?my_dir2 rdf:type cim:Win32_Directory .
        ?my_assoc_dir2 rdf:type cim:Win32_SubDirectory .
        ?my_assoc_dir2 cim:GroupComponent ?my_dir2 .
        ?my_assoc_dir2 cim:PartComponent ?my_dir3 .
        ?my_dir3 rdf:type cim:Win32_Directory .
        ?my_dir3 cim:Name ?my_dir_name3 .
        }

content_snippet_Testing_Win32_Directory_Win32_SubDirectory_Win32_SubDirectory.txt