[Dell PowerEdge R620 II] Logical processors disabled in BIOS but HT still enabled on OS

Hi,

We just received a new Dell PowerEdge R620 II and for applicative requirements we have to disable HyperThreading on the server. As usual I disabled the Logical Processors option in BIOS but the OS (RedHat Enterprise Linux 5.8) is reporting 12 threads (CPU is an Intel E5-2630, only one installed). I tried to flash the BIOS with no luck, OS still reporting 12 threads, also tried with Fedora Core 17, same result.

I also checked another R620 II we received earlier, it doesn't have this bug.

Any idea?

Thanks!

Regards,

Florian