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The Ryzen APU duo
Now that we're sufficiently up to date with AMD's foundations for Raven Ridge, let's talk about the two implementations of the SoC that AMD is announcing today.

  Cores/
threads
Base
clock
(GHz)
Boost
clock
(GHz)
GPU
compute
units
GPU
peak
clock
L3
cache
TDP RAM
support
Ryzen 7 2700U 4/8 2.2 3.8 10 1300 MHz 4MB 15W Two channels
DDR4-2400
Ryzen 5 2500U 2.0 3.6 8 1100 MHz

The Ryzen 7 2700U will tap four Zen cores and eight threads running at 3.8 GHz boost and 2.2 GHz base speeds. The integrated GPU boasts 10 Radeon Vega compute units for a total of 640 stream processors. AMD calls this integrated GPU "Vega 10 Processor Graphics" in its footnotes, so expect that branding to show up in marketing materials and on spec stickers. AMD suggests a 1300 MHz boost clock for the integrated GPU, but it isn't going into more detail about base or typical speeds today.

The Ryzen 5 2500U will offer the same four cores and eight threads as its bigger brother, but they'll run at lower clock speeds: 3.6 GHz boost and 2 GHz base, to be exact. The Ryzen 5 chip also loses two Vega compute units in the bargain, so it could carry a Vega 8 Processor Graphics sticker. The Vega 8 integrated GPU has 512 stream processors, and AMD claims peak clock speeds of up to 1100 MHz for this IGP.

To get their quad-core layouts, both CPUs implement one Zen core complex (or CCX) provisioned with 4MB of shared L3 cache. That's the smallest L3 cache we've seen on a Zen CPU so far, down even from the 8MB in the Ryzen 5 1400. Each Zen CCX can have as much as 8MB of L3, so it'll be interesting to learn whether this choice was made for power savings, market segmentation, or some other reason.  Each chip will retain 512KB of L2 cache per core, though, and they'll be able to run with DDR4 memory at speeds up to 2400 MT/s.

Both of these chips will nominally run within 15W power envelopes, although system integrators will be able to squeeze them into TDPs as low as 12W or open up headroom to as much as 25W. Intel's eighth-generation Core i7s can squeeze into machines dissipating as little as 10W, or as much as 25W, so AMD's chips should offer designers about about as much flexibility.

A sneak peek at performance
No CPU announcement is complete without performance numbers, and AMD offered us a few tidbits from its internal labs to whet our appetites. As usual, I'd caution reading too much into these results. In part, that's because the company chose an Acer Spin 5 notebook as its host for the Core i7-8550U that's going up against the Ryzen 7 2700U in these tests. It's a 13.3" notebook that's just 0.63", or 16 mm, thick. My guess is that this laptop is likely quite thermally constrained given its compact body and small footprint.

I only bring this up because AMD included a set of test numbers for an Acer Swift 3 notebook with a Core i5-8250U in in its notes that it didn't graph. I'm never one to let good test data go to waste, so I went to the trouble. Swift 3 notebooks come in 14" and 15.6" bodies, so they could offer better cooling potential than the 13" Spin 5. With the same four cores and eight threads as the i7-8550U, the potentially better-cooled i5-8250U doesn't prove as easy a match for the AMD side of the court. Keep these numbers in mind as we examine AMD's internal performance figures, and note that AMD didn't offer any details of its reference notebook for either of its SoCs. We have no idea how slim or well-cooled that machine might be.

Cinebench is first up. The company's internal testers pitted the Ryzen 7 2700U against Intel's second-best Core i7s from the Kaby Lake and Kaby Lake Refresh generations: the Core i7-7500U and Core i7-8550U. The Ryzen 7 2700U basically matches the Core i7-7500U in the single-threaded portion of Cinebench, and it's about 10% short of Intel's latest-and-greatest. That performance bodes well for the kinds of lightly-threaded workloads most people tend to spend most of their time doing on the average PC.

Zen CPUs tend to do well in Cinebench's multi-threaded test, as well, and Ryzen APUs are no exception. For heavier-duty use, the Ryzen 7 2700U puts up an impressive Cinebench all-thread score of 719, or a whopping 44% faster core-for-core and thread-per-thread compared to the Kaby Lake Refresh part. This best-case showing for Raven Ridge suggests prodigious multithreaded performance potential for the 15W power envelope.

In the range of applications that AMD provided (but didn't graph) data for the Core i5-8250U, however, it becomes clear why the Spin 5 and its Core i7-8550U might not be the most representative implementation of that chip. Whether in POV-Ray, PCMark 10, TrueCrypt, or PassMark 9, the Core i5-8250U in the Swift 3 beats out the Core i7-8550U in the Spin 5. In whatever reference design AMD is using for the Ryzen 7 2700U and Ryzen 5 2500U, both SoCs clearly have enough room to stretch their legs, and that might explain the rather wide gaps between the Ryzen 5 2500U, the Ryzen 7 2700U, and the Core i7-8550U in some tests. We'd be curious to see what would happen if one were to put the i7-8550U in the Swift 3. Still, the Ryzen APUs remain quite competitive with the Intel parts given these caveats.

Of course, many prospective Ryzen APU buyers will be more interested in these chips' gaming chops than anything, and if 3DMark Time Spy is any indication, the Vega 10 processor graphics in the Ryzen 7 2700U could prove quite compelling if the price is right for notebooks built with this chip. The 2700U more than doubles the performance of Intel's UHD Graphics 620 IGP in the Core i7-8550U, and it matches a result taken from the public 3DMark database for a machine with a Core i7-7500U and a GeForce GTX 950M inside. Of course, a scroll through 3DMark's databases also shows a variety of similar Core i5-7500U-and-GTX-950M systems with scores well over 1000. Don't throw out your gaming notebook just yet.

AMD didn't provide competitive numbers for Intel's UHD Graphics 620 IGP in real-world games, but the Ryzen 7 2700U still puts up a good showing. Acceptable performance with reasonable graphics quality in immensely popular games like League of Legends and Dota 2 at 1920x1080 would probably seal the deal for many mainstream gamers, but potentially playable performance at 1920x1080 with Counter-Strike: Global Offensive might not hurt, either.

The seemingly magical results for Overwatch are tempered by the fact that the Ryzen 7 2700U achieved them with low settings at 1280x720 and with a 79% render scale. Some might be able to tolerate those settings, but full-HD gaming this is not. Comparison data with Intel's UHD Graphics 620 IGP would be nice to see, but if frame-time performance jives with these FPS numbers, gaming on a high-end Raven Ridge machine seems likely to prove a better experience overall than with the common UHD Graphics 620.

Although it's not pitting Ryzen Mobile CPUs against Intel parts in the battery life department, either, AMD does claim large increases in longevity from its Ryzen APUs compared to Bristol Ridge parts. That most drastic improvement comes in VP9 video playback, where the Vega GPU is likely able to accelerate decoding that the Radeon graphics on Bristol Ridge can't. Likely thanks to that help, the Ryzen 7 2700U delivers twice the battery life as the FX-9800P does. In H.264 playback and MobileMark 14, the gains are less drastic, but 15% to 26% better battery life is still nothing to sneeze at.