[Beowulf] Re: amd 3 and 6 core processors

[David Mathog]

Jonathan Aquilina <eagles051387 at gmail.com> wrote:

> a friend of mine told me that the amd tri cores were quads with one core
> disabled?

Probably.  It will often be the case that the disabled core is
defective, maybe not fully dead, but it did not pass all of its tests. 
It is common practice to recycle multicore CPUs with one bad CPU and
sell it as a lower performance part.  Similarly, chips that won't run at
full speed, but will pass all tests at a lower speed, may be stamped as
a lower performance part and shipped as that.  It makes good business
sense to do this since it lets them recover the otherwise wasted
production costs on these partially defective devices.  They may also
disable the 4th core even if works perfectly, and sell it as a 3 core
device, when they have an order for the tricore that needs to be shipped
and not enough quadcore chips on hand with one bad core to fill it.

Regards,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech