Image 1 of 1 (Image credit: Imgur)

AMD's first-gen Ryzen processors are selling at all-time low pricing, but it turns out that some of these chips are filtering out into the hands of enthusiasts with an unexpected surprise: The 12nm process, which is more efficient and faster than the original manufacturing process used with AMD's freshman Ryzen chips.

The original Ryzen 5 1600 landed with six cores and twelve threads powered by the 14nm GlobalFoundries process, but a new "AF" version has appeared at retailers for a mere $85 and apparently comes with the 12nm Zen+ architecture.

AMD's second-gen Ryzen processors debuted with the new 12nm die, and while the new process didn't offer smaller transistors or a new grounds-up architecture, it did bring performance and efficiency gains compared to the original Ryzen's 14nm LPP process. AMD tweaked the Zen architecture, which it dubbed Zen+, to support higher frequencies, more sophisticated multi-core boost rates, and faster memory/caches that together yielded a ~3% increase in instruction per cycle (IPC) throughput.

All of these advances made the Ryzen 5 2600 a solid step forward over the 1600, and though it certainly isn't a given, it's logical to assume the AF versions of the Ryzen 5 1600 could benefit from some of those same advantages.

First, you need to look no further than the box, or the chip itself, to spot a new AF model. The original 14nm Ryzen 5 1600 models (released in 2017) come with the YD1600BBAEBOX product identifier, while the new models (released circa November 2019) come with the YD1600BBAFBOX part number.

Image 1 of 2 (Image credit: Imgur) Image 2 of 2 (Image credit: Tom's Hardware)

As we can see in the picture above (posted by redditor u/_vogonpoetry to Imgur), the first line of code on the IHS of the processor now also ends in "AF" for the impacted parts. As you can see from the second image, which is of our original 1600 sample we received from AMD, the older version comes with "AE" at the end of the code.

Image 1 of 2 (Image credit: Imgur) Image 2 of 2 (Image credit: Imgur)

The "AF" identifier was originally thought to classify the chips as two different steppings of the 14nm Zeppelin die (B1 and B2, respectively), but common test utilities, like CPU-Z and HWInfo, identify these chips as 12nm parts. There is a chance that this is merely a mistake in the product identifier strings programmed into the chips, but we've reached out to AMD for official comment and will update as necessary.

Even though these chips come with the 12nm process, AMD has left the clock rates for the 1600 the same as before, so you don't get any top-line improvement there.

One redditor recently scored an AF model and put it to the test, noting:

"Interestingly this CPU boosts to 3.7GHz, 100MHz higher than the normal 3.6 boost which I thought was weird so I went back and checked the old AE chip and it too boosted up to a 37x multiplier, but only very briefly. Under any load, even 1-2 cores, the old chip fell to 3.4GHz. But this new AF chip was able to sustain 3.7 for longer periods which is only 200 MHz lower than the real 2600. The stock all-core boost algorithm is also much improved, still boosting to 3.6 GHz under cinebench load which is quite a bit higher than the 3.4 of the "AE" 1600. I expected to see only the 3% IPC gains of the Zen+, but the actual performance is much better, and it scores a full 400 pts higher in R20. In CPU-Z we can see 12nm listed and Pinnacle Ridge, matching the 2600. Memory Latency is reduced as well thanks to Zen+'s IMC.

Also interesting that Ryzen Master complained about the CPU being unsupported until I updated it. I was a few version out of date, but not that old... They must have had to add special support for this chip?"

Now, that certainly doesn't mean that all of these AF revision 1600's will offer these same advantages, but it does bode well for enthusiasts willing to spend what we would consider a paltry sum for the very capable AF version of the Ryzen 5 1600.

Naturally, we would expect the advantages of the faster process to crop up when overclocking, but from the redditors' experience, that is still very much up to the silicon lottery: The AF model wasn't able to hit the same overclocked clock speeds as the standard Ryzen 5 1600. The redditor also found they couldn't overclock the memory as effectively, but bear in mind that the lion's share of memory overclocking gains with the second-gen Ryzen models came from improvements made to trace routing on motherboards and tuned BIOS revisions, so your mileage may vary with a better motherboard.

The newer AF models also come with the Wraith Stealth cooler, which is a lesser cooler compared to the Wraith Spire that came with the original 1600 models.

Cores / Threads Base / Boost (GHz) Process Ryzen 5 1600 6 / 12 3.2 / 3.6 14nm / 12nm? Ryzen 5 2600 6 / 12 3.4 / 3.9 12nm

All of this begs the question: Why has AMD suddenly introduced 12nm die to the first-gen Ryzen processors? There are several theories, with the most obvious being that these are, in fact, 14nm processors that have been mistakenly programmed to identify as 12nm. Another likely explanation is that these are simply Ryzen 5 2600 die that didn't make the cut for that class of chip due to frequency targets, but because they meet the criteria required for a 1600 model, it is simply more economical for AMD to use the die in the older chips.

We expect to learn more about the capabilities of this apparent new revision as more chips land in the hands of enthusiasts.

It will be interesting to see if AMD begins updating other first-gen Ryzen chips to the 12nm process. We've reached out to AMD for comment and will update as necessary.