>Yes, the server is dedicated to SQL only... I think it's enought powerfull. Specs are an IBM X-Series 445, with Quad proc XEON 3 Ghz 4Mo Cache, 8Go RAM, 6HD 15000rpm Raid-5. I was alone connected on the DB with the Query Analyser, directly on the server to make tests.
Try using the MAXDOP option as a test in the query.
I had a problem once in version 7 that the query plan had a problem with too many processors. I set the procedure to use one processor and it reduced the time by half. It is only rare that you have to do this, but it might be worth a try.
i.e.
SELECT * FROM yourtable
OPTION (MAXDOP 1)
DEFINITION
==========================
OPTION (MAXDOP number): Tells the Query Optimizer, for this query only, to override the "max degree of parallelism" setting, specifying the maximum number of CPUs that can be used for parallelism, when creating the query execution plan.
max degree of parallelism Option
Use the max degree of parallelism option to limit the number of processors (a maximum of 32) to use in parallel plan execution. The default value is 0, which uses the actual number of available CPUs. Set max degree of parallelism to 1 to suppress parallel plan generation. Set the value to a number greater than 1 to restrict the maximum number of processors used by a single query execution. If a value greater than the number of available CPUs is specified, the actual number of available CPUs is used.
Note If the affinity mask option is not set to the default, it may restrict the number of CPUs available to Microsoft® SQL Server™ on a symmetric multiprocessor (SMP) systems.
Change max degree of parallelism rarely for servers running on an SMP computer. If your computer has only one processor, the max degree of parallelism value is ignored.
max degree of parallelism is an advanced option. If you are using the sp_configure system stored procedure to change the setting, you can change max degree of parallelism only when show advanced options is set to 1. The setting takes effect immediately (without a server stop and restart).
In addition to queries, this option also controls the parallelism of DBCC CHECKTABLE, DBCC CHECKDB, and DBCC CHECKFILEGROUP. Parallel checking can be overridden by using trace flag 2528. For more information, see Trace Flags.
