Unlocking second core

pickarooney

OK, this is a total newbie question but what exactly happens when your BIOS prompts you to press a key (4 in this case) to unlock an extra core on your CPU? Is it literally just enabling the second core or is it some sort of simplified overclocking option?

What possible reason would there be for both cores not to be enabled as standard?

Solitaire

It only works if you have a cut-down AMD CPU. And even then its a gamble as the additional core(s) may be defective and not work - the PC will crash, and then reboot.

To unlock cores you need a 45nm Sempron (unlocks to a 45nm Athlon X2), a 45nm Athlon X3/X4 or a 45nm Phenom X2/X3 (all can potentially unlock to a 45nm Phenom X4, but the extra cores or L3 cache may be defective). In all cases you may notice the CPU running a lot hotter - many mobos run an unlocked CPU at a higher voltage to keep a marginal unlocked core stable.

pickarooney

Hmm, so in my case (AMD Athlon II X2 255) it won't really have done anything except change the BIOS spashscreen?

Solitaire

There's a rumour that a few of the aftermarket 45nm Athlon X2s are actually cut-down Phenoms due to the purpose-made chips all ending up in the OEM sector. All you can do is try to unlock it and see if CPU-z decides your CPU has suddenly mutated into something new and strange

pickarooney

It seems to identify as the same thing afterwards. Well, I wasn't really expecting to find a third, hidden core