Dual-core versus Quad-core

[apisorder]

I remember in some iterations of Windows one can disable multi core booting, and it led me to ask a rather unusual, probably dumb, question: why can't you buy an Intel Core i3/i5 processor and enable its Core i7 features?

I don't think it's the two-core versus quad-core difference, correct?

Even if they were hard wired, it is still the same chip, isn't it? So why can't we?

Thanks.

 

[rush21hit]

To answer this question you must understand how Intel's Core series are made and why they classify its tier as how we know it today.

Basically, the production of Intel CPU for desktop, and perhaps for some Xeon series as well, are divided into 2 categories. The first is a dual core die and the second is the quad core die. An i3 is essentially a dual core die that pass certain quality test to have multi-threading capabilities. Even then, the said capabilities varies among those printed dies.
And so does the quad core dies.
So no one can simply enable or disable something that has inherently set to the designated class of performance. Some limiter are deliberately done for price-performance segmentation, some are simply faulty stuff that got disabled altogether.

This method of diversifying performance class of the printed chip are for good reason. Aside from price segment, not all chip are created equal. Even among the same class. In fact, even among the same silicon wafer.

The quality test which determine the performance level of the chip then categorized and named accordingly.

So for the lesser dual-core die design, they goes to the Pentium G section. Pass certain test, they can go to an i3 tier.
This also applies to the quad core chip which we have the i5 and the i7.

 

[R_1]

its not like AMD where stuff is turned off. the units are disabled, physically.
either they did not work properly and were binned as a lower part or they are physically disabled, I think the term laser cutting comes into play here.
Intel laser cut traces in the past, people with conductive pens and pencils were enabling features, I believe Intel learned from this and made it much harder, nigh impossible to reverse. (celeron to pentium)

While a motherboard can at will disable any core it wishes it cannot physically repair damage to the CPU.
this is my simple understanding of the situation.