If I recall correctly when reading the LinX thread, back in first quarter 2011 when SandyBridge was new the linpack libraries used by LinX stressed the CPU harder when CPU was set to 4C/4T in bios. Since the new linpack libraries came out I believe its stated in the LinX thread that 4C/8T now stresses just as hard or harder.
Make sure you download the latest LinX and Linpack libraries and then re-run using 4C/8T. Let me know if you cant find them and I will PM you the link
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