PII 720 Quad Core !! (not a typo)

[ecat]

I've not seen this done before so thought I'd share...

That's strange...

That's very strange...

But true, four cores as near as I can tell. Manually setting the CPU affinity while running SuperPI I can stress each core individually, I don't know what other tests I can perform to prove its quad corelyness.

There is of course a down side, even at 1GHz Prime95 on all cores fails, but with another chip, well, who knows ?

And how do we unlock this 4th core ? Simple. On an Asus M3A79-T running the 703 bios you enable ACC. That's it

Oh well, so I really do have a quad cripple, or is this just some SW anomaly ? Still @ 3.8GHz this cripple rocks

 

[ecat]

Task manager shows 4 cores too, as does Prime95 and everything else I've tried

 

[ecat]

Even at 1GHz I get failures so not much point investigating further. More of a curiosity, for my little cpu at least. The memory controller is common to all cores I think, so there's not much point in playing with bus speed either.

It does boot at full speed, just means the bad core is not stressed during start up I guess. Here's the validation page

http://valid.canardpc.com/show_oc.php?id=510443

The other down side is that I can't use ACC, reports vary but some are getting an extra 200 to 300MHz with it enabled. It would be nice to hit the 4G mark.


Hello to the guys on Xtreme, I'm still waiting for my authorisation e-mail

humm, I wonder if the same trick will work on the rumoured dual-cores ?

 

[ecat]

That is quite interesting.. does this work with all X3 processors?

It's a lottery I'm afraid. Some X3's don't unlock. Of the X3's that do unlock some, like me , have a 4th core incapable of even 1GHz, others have better luck reaching full rated speed or even beyond...
http://www.xtremesystems.org/forums/showpost.php?p=3675438&postcount=11

I was going to try this with my 720be on a new Gigabyte 790FX AM3 mobo. This board boasts the ACC feature but I cannot find anything in the bios about acc. Also I have tried different versions of overdrive and they all display the ACC settings as disabled (greyed out).

Does anyone know about setting up this feature on the AM3 board?

The PII processors should not need ACC, it looks like some mb manufacturers, but not all, are disabling/removing the ACC feature when a PII is detected.