Athlon 64: How AMD turned the tables on Intel

I wanted to mention that the Pentium 4 (Prescott) that was marketed as the Centrino in laptops had 64bit capabilities, but it was described as 32bit extended mode. I remember buying a laptop in 2005(?) which I first ran with XP 32bit, and then downloading the wrong Ubuntu 64bit Dapper Drake image, and the 64bit kernel was running...and being super confused about it.

Also, for a long while, Intel rebranded the Pentium 4 as Intel Atom, which then usually got an iGPU on top with being a bit higher in clock rates. No idea if this is still the case (post Haswell changes) but I was astonished to buy a CPU 10 years later to have the same kind of oldskool cores in it, just with some modifications, and actually with worse L3 cache than the Centrino variants.

core2duo and core2quad were peak coreboot hacking for me, because at the time the intel ucode blob was still fairly simple and didn't contain all the quirks and errata fixes that more modern cpu generations have.

Are you referring to PAE? [1]

[1] https://en.wikipedia.org/wiki/Physical_Address_Extension

Pentium 4 was never marketed as Centrino - that came in with the Pentium M, which was very definitely not 64-bit capable (and didn't even officially have PAE support to begin with). Atom was its own microarchitecture aimed at low power use cases, which Pentium 4 was definitely not.

Speaking of marketing, that era of Intel was very weird for consumers. In the 1990s, they had iconic ads and words like Pentium or MMX became powerful branding for Intel. In the 2000s I think it got very confused. Centrino? Ultrabook? Atom? Then for some time there was Core. But it became hard to know what to care about and what was bizarre corporate speak. That was a failure of marketing. But maybe it was also an indication of a cultural problem at Intel.

Centrino was Intel's brand for their wireless networking and laptops that had their wireless chipsets, the CPUs of which were all P6-derived (Pentium M, Core Duo).

Possibly you meant Celeron?

Also the Pentium 4 uarch (Netburst) is nothing like any of the Atoms (big for the time out-of-order core vs. a small in-order core).

In 2005 you could already buy Intel processors with AMD64. It just wasn't called AMD64 or Intel64; it was called EM64T. During that era running 64-bit Windows was rare but running 64-bit Linux was pretty commonplace, at least amongst my circle of friends. Some Linux distributions even had an installer that told the user they were about to install 32-bit Linux on a computer capable of running 64-bit Linux (perhaps YaST?).

No, EM64T

PAE is a 32-bit feature that was around long before AMD64. OP means EM64T: https://www.intel.com/content/www/us/en/support/articles/000...

AMD was a no-brainer in the mid 2000s if you were running Linux. It was typically cheaper than Intel, lower power consumption (= less heat, less fan noise), had 64bit so you could run more memory, and dual core support was more widespread. Linux was easily able to take advantage of all of these, were as for Windows it was trickier.

Very early intel "EM64T" chips (aka amd64 compatible) had too short virtual address size of 36bit instead of 40, which is why Windows 64bit didn't run on them, but some linux versions did.

Rest is well explained by sibling posts :)

Core is confusing. Of course it's a Core 2. It has 2 cores in it. Core 2 Quad? Obviously has 2 cores... oh wait, 4. i3/i5/i7 was reasonable except for lacking the generation number so people thought a 6th gen i3 was slower than a 1st gen i7 because 3 is less than 7. Nvidia seems to have model numbers figured out. Higher number is better, first half is generation and second half is relative position within it. At least if they didn't keep unfairly shifting the second half.

The is what happens when marketing gets involved. The worst of the worst being INTC marketing dept.