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Old 12-23-2015, 05:55 PM
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Originally Posted by sdlvx View Post
Zen has the opportunity to make Bulldozer cores look like a dark age for AMD. If AMD comes back and people realize that they're potentially back to K8 days, they'll be much, much better off. People under-estimate the influence corrupt tech media has over people, and how uninformed people can just look at AMD and think that now competitive products beyond $200 range means the whole company's product line is bunk. Even with them buying ARM devices in droves and not caring. Only problem is a lot of HEDT people today are young and probably didn't even have a computer in the K8 days. I think their insistence that "Intel is amazing" comes from the fact they missed out on times when Intel was pretty terrible, like Netburst.

As for adding value, I think AMD is going to do it by adding more cores for the same price as an Intel. I.E. your purchase choice becomes between a 6700k or a six core Zen. AMD will be very cost competitive with Intel in those ranges since their dies are going to be much smaller and lacking an integrated GPU.

I basically image Zen quads to compete price-wise with Intel duals, Zen hex to compete with quad (low bins compete without HT and high bins compet with Intel quad with HT), and hex and octo to compete with cheaper intel hex and more expensive hex core. AMD will lose their price to die size advantage (or a part of it) on s2011 chips since those don't have as much fluff on the chips to add to die size, but if you are the type of person thinking about a hex core Intel, for a few hundred more than the hex and a few hundred less than octo EE Intel, a Zen 8 core sounds really appealing.

I'm assuming Intel has to pay more per wafer for a 14nm chip, specially since they do their own R&D and they don't have significant customers. That and a die on something like Intel dual core is mostly GPU, a lot of waste. AMD can just sell harvested 8 core parts with 4 cores active and really rake Intel over the coals in price.
This is alleged 6700k die map. Half of it is GPU. If Zen doesn't have GPU, Intel and AMD pay similar per mm^2 of die, and Zen is close to Intel in single thread, AMD should have no problem massively undercutting Intel.
The basic Zen compute unit has at least 4 physical cores. So Zen based CPU models would scale in steps of this size.

I found this line in a family 17h related patch:
+ core_complex_id = (c->apicid & ((1 << bits) - 1)) >> 3;

The highlighted part suggests a "core complex" size of 8. As it works directly on an APIC ID masked by a core bit mask with no sibling bit correction, this might even mean 8 physical cores per "core complex". The minimum (as seen on leaks) would be 4 physical cores with "SMT-2" per core complex.

Young generations might be influenced not only by the media, but also by active "veterans", who are waiting for an AMD comeback. But I'll just watch that story to unfold itself.