There is a core war taking place between AMD and Intel, with both companies designing CPUs with increasing numbers of physical cores and threads to throw at compute workloads. This is happening in the mainstream space as well, not just in the enthusiast and server sectors. AMD currently has the lead in that regard, and may aim to keep it with Zen 2, which is rumored to include 16-core CPU options.
Before we dive into the rumored Zen 2 details, let's talk a moment about the naming scheme. Zen is the name of the underlying architecture in AMD's Ryzen and Threadripper CPUs. In the mainstream market, there have been two generations of Ryzen so far—the original Ryzen launch based on 14nm Zen, and the more recent second generation Ryzen parts based on 12nm Zen+, which is a refinement of Zen. Zen 2 is what comes next.
The above is an earlier slide depicting AMD's roadmap. Everything is the same, except instead of a 14nm+ node, AMD shrank things down to 12nm, which is commonly referred to as Zen+. As for Zen 2, the architecture shifts to a 7nm manufacturing process and will bring about better performance and, presumably, improved power efficiency. Here's a look at an updated roadmap:
We're including both roadmaps here for clarity, as you might stumble upon either one when looking up Zen on the web. Hopefully this helps clear up any confusion that might exist. Moving on...
AMD has previously stated that Zen 2's design is already complete. More recently, AMD talked about sampling its 7nm chips to clients.
"We have a 7nm GPU based on Vega that we'll sample later this year. We have a 7nm server CPU that we'll sample later this year. And then, obviously, we have a number of products that are planned for 2019 as well. So it's a very, very busy product season for us. But we're pleased with the sort of the execution on the product roadmap," AMD CEO Dr. Lis Su said in April.
So there's a bit of a primer on Zen to date. As we look ahead to 7nm Zen 2 products, there are very little concrete details to go on. Most of what's out there are rumors and speculation. The most recent of those suggests that Zen 2 will introduce a 10-15 percent IPC (instructions per clock) uplift over 12nm Zen+. There's not a whole lot to the rumor, just a post in a Chinese web forum without any real context.
The same source also points to Zen 2 introducing up to 16-core processors for AM4 platforms (mainstream), up to 32-core chips for TR4 (enthusiast), and 64-core solutions for SP3 (server). If that turns out to be right, AMD will maintain bragging rights over Intel as it pertains to cores and threads, at least in the mainstream sector. Intel is rumored to finally be releasing a mainstream 8-core processors under its 9th Gen Core banner (Coffee Lake Refresh), but AMD has been there since the launch of Ryzen.
From our standpoint, the IPC bump is more interesting. Outside of specific tasks, a higher IPC will have a greater impact on day-to-day performance than building more cores, which often come at the expense of clockspeed. Many of today's applications just aren't coded to take full advantage of several cores and threads, unfortunately.
We'll have to wait and see how things shake out. What looks clear, though, is that AMD's comeback is not a temporary thing.