I'm really new to overclocking, so bear with me. Got an AMD Phenom IIx2 550 CPU running it with an Asus Evo Motherboard and 2x2G DDR3 Memory and an ATI Radeon 4800 1g DDR5 graphics card. My CPU just wont unlock to Quad core, but I've managed to get it overclocked from the base 3.1Ghz to 3.6Ghz. Is there anyway to tell if I can unlock it to Quad core? I'll read up some more on it but really need some help.
I'm not sure if Asus can unlock the extra cores, maybe by updating to a new bios. From what I understood, the disabled cores on AMD's are faulty cores, enabling them might give some extra performance but might ruin your cpu. Biostar bioses are able to unlock those cores, but you'll have to buy a new motherboard and imo stick with Asus.
You need to find out if your MB has ACC function, if it has you need to turn it ON. that way you'll be able to unlock other cores. But reality is that that most of those CPU's wont unlock or even if you'll succeed unlocking your system might become unstable. If you'll unlock them and everything will work ok, test your CPU with prime95 for stability, if that's ok, you'v got a good chip. Good luck with it m8.
They were locked because the cores were not fully functional, were faulty in some way, or they were disabled simply because more people wanted to buy dual-cores and if AMD can sell more chips at a lower price, it's better than selling little or no chips at a higher price. If you got a chip because of the last reason, then it's basically a 955 for 2/3 of the price.
I can't wait to start seeing Phenom II x2 555's overclocking in this forum. I've seen pre-release ones go to 4.2ghz without touching 1.45V.
Last night I gave up trying to unlock to Quad Core using my Bios (May read up on other Bios available), but did manage to get it Overclocked to 3.5Ghz over Dual but within 15min of testing I got Blue screens, friend of mine says its an overheating problem (As I'm still using stock heatsink, will replace today) but even with case open and fan pointed directly into the case I still get them, so just reset the Bios and screamed at myself in the mirror.
So frustrating as friend has the same CPU and its running Quad with no problems.
Blue screen is more likely a result of the overclock than heat. If you up the frequency too much without increasing the voltage that can lead to errors and thus a blue screen. Of course using too much voltage could fry the CPU.