Recently I've reformatted my OS (Windows 7), but this time I used a different version of W7 (Ultimate) since I had lost my Home Premium disk (Yeah, logically I should have installed Ultimate instead of Home Premium, but I randomly found the Ultimate recently..)
And after re-installing all my utilities/programs, I noticed in CPU-Z that during Prime95, my multplier, which was set to 42, was running at 39 and just sat there at 39. usually when I stress test the CPU on this multiplier it jumps between 40-42, though the CPU seems to be only rated for 34, I've been able to hit 42 before; http://valid.canardpc.com/show_oc.php?id=2395157
Also, when NOT under stress testing, the CPU starts jumping from 16-41 (despite the fact I've disabled both SpeedStep and Turbo) and as said above, under stress testing, the CPU just refuses to go above 39. I've seen threads (pun not intended) like these before, but none of them seem to have helped my situation.. Before the reformat, my CPU kept causing BSODs constantly, I assumed that my CPU was failing, but just to make sure, I reformatted and my BSODs have disappeared! But now my multiplier doesn't go above 39..
And currently, my CPU is running on a 16x multiplier..
And yes, I'm well aware of the fact I have a 2600 and not a 2600K, don't ask.
Ok first of since the speeds that you are listing are the non overclocked speeds for the Intel® Core™ i7-2600 and Intel Core i7-2600K. Now since you are using the Intel Core i7-2600 which will not allow you to change the multipliers they are locked and not able to be changed. The only way in which you can change the speed for the Intel Core i7-2600 is by the old school BLCK. I don't know what else to tell you.