A few weeks ago, I exclusively reported on AMD’s new APU family, codenamed Bristol Ridge (hey, it’s not often that I write about something no-one else on the internet does!), and leaked performance tests from the Geekbench website showed that Bristol Ridge would be a sizeable increase in performance over Kaveri, and in performance-per-watt over Intel’s Skylake platform as well. Last night AMD officially launched their new mobile platform and in some countries these notebooks are shipping today with AMD’s 7th generation of APUs. The details about these chips are pretty interesting, and it turns out that AMD is making two chips for the mobile segment instead of one.
The platform is still pretty much Bristol Ridge on the socket FP4 BGA socket, but it’s now shared by something AMD calls Stoney Ridge. This is the dual-core version of Excavator on the same platform, which explains why I saw two different AMD family IDs when searching for new APU listings on Geekbench. Bristol Ridge’s die size comes in at 240mm², while Stoney Ridge is 124mm². Both chips are developed for higher performance with lower power consumption, but they’re also both smaller and cheaper to manufacture than previous APUs based on the Excavator architecture – Carrizo mobile, specifically the full-fat FX-8800P, had a die size of 245mm². Every dollar saved counts when it comes to low-margin, mass-volume parts like these.
Here’s the full lineup of APUs offered by AMD. Notice that some of them have the letters “cTDP” with a wattage range – this is that configurable wattage rating that the notebook OEMs can set for systems based on these chips, and you’ll notice that some of these chips can also be set to run with a 45W TDP. Anything based on those APUs will be much faster than the variants with lower TDPs going into a mobile chassis, so I wouldn’t be surprised to see someone like Acer slap the FX-9830P into their latest Nitro V chassis and add discrete graphics to it and call it a day with a 45W TDP. That would be, for AMD, an incredibly fast system.
The base and boost frequencies are also much higher than previous generations of APUs in the mobile space, and in particular the FX-9830P is reaching a bit into desktop territory with a 3.7GHz boost clock. The lower-end series, namely the A6 and E2 chips, have a much more limited base and boost clock range, but the value here is that the single-threaded performance is high thanks to those improved clock speeds. That should improve the user experience quite a bit.
I’m personally hopeful that I can upgrade to a netbook with the A10-9600P APU in the future, as my current one is starting to show strain just running Windows 10 and Chrome with a couple of browser tabs open, not to mention how agonisingly slow Microsoft’s Edge browser takes to load a webpage.
Compared to the older Excavator architecture found in Carrizo mobile, AMD has somehow managed to make some very nice improvements in single-threaded performance and increase the amount of power available to the graphics cores at the same time as the CPU. They’re quite capable of stomping all over Intel when it comes to integrated graphics performance, but there are also sizeable performance boosts over Kaveri mobile processors from two years ago, and a 38% overall boost in synthetic benchmarks compared to mobile Trinity APUs from around 2013.
What’s also telling is the 52% claimed performance boost over previous Excavator designs in entry-level markets like the ones served by the A6, A4, and E2 APU families. I wrote about the absurdly high performance boosts to chips like the A9-9410 in Geekbench, and it looks like those were real results – AMD will probably bury Intel’s Atom family with this update if Intel doesn’t think about what counter-moves it can make in a short period. The chip giant launched their Braswell platform last year, but it hasn’t been setting the world on fire since its launch, and those integrated GPUs are certainly no good at playing Counter-Strike: Global Offensive very well.
AMD’s brief overview of the latest changes to Excavator are quite self-explanatory. H.265 support with possible HDCP 2.2 capability means that devices with these chips accessing services like Netflix won’t have issues in future with playing back protected video content. At the same time, there are also improvements to video playback that extend battery life, so you can binge watch more The Blacklist episodes as you try to catch up with your friends. DDR3 and DDR4 RAM is supported, but it you’re far less likely to run into any systems still running DDR3-L memory these days. DDR4 is the way to go.
One interesting aspect here is the inclusion of twelve lanes of PCI-Express 3.0 connectivity. My expectation is that some notebook vendors are going to design motherboards that either support one M.2 PCI-Express x4 connection to the CPU, or two PCI-Express x2 SSDs alongside each other in a RAID array. The rest of the lanes might be used for a discrete graphics solution, which at this moment won’t be Polaris 11. Refreshes of Radeon GPUs in the laptop market might happen this year, but this is still way better than anything Intel is pushing with their integrated graphics performance.
Also note that Bristol and Stoney Ridge are both full systems on a chip (SoC), which is another differentiator compared to Carrizo mobile and on the desktop. Future versions of Bristol Ridge on the deskop socket AM4 platform might be full SoCs as well, removing the need for motherboard vendors to create designs with a chipset installed.
One of the primary ways in which AMD is increasing performance on Bristol and Stoney Ridge is that they’re increasing clock speeds dramatically to get boosts in single-threaded workloads. The myriad of other tweaks they’ve made to the chip now, though, aren’t as easily explained away, and the primary one is called Shadow Pstates. This is based on a technology called adaptive voltage frequency scaling (AVFS), and it helps the performance of both good and bad CPU dies that AMD might create for mobile solutions. In the top graph, the APU’s delivered voltage is represented with the blue line, but it’s resulting in a noisy system that kicks the fans on full, tries to run at full power when it can, and might mistake a lack of power delivery for thermal throttling, hampering performance.
With AVFS working, the APU is better able to match the rated clock speed to the given voltage and avoid throttling or scenarios where the APU thinks it is power limited. On boot, at the POST sequence the system also runs a health check on the APU and will adjust the AVFS curve as needed as the APU gets older and the silicon starts to degrade. This is a massive improvement over power management in older systems, and is one of the reasons why Bristol and Stoney Ridge can hold their boost clocks for much longer than previous generations of APUs.
Other parts of the health check, like a reliability tracker, will assess the health of the APU at post and may adjust the curve up in some places to maintain performance over time.
The benefits to this move overall seem positive. At the high-end, where consumers are most likely to be buying these parts, the A12 and A9 series of APUs promise to be good value for money. The A12 and FX chips will see anything from a 10% to 20% jump in overall performance compared to similar chips on the Carrizo platform, while the A9 family will take the fight to Intel’s Skylake Core i3 systems. It might beat a Core i3 processor in a lot of workloads, and it might not, and being a dual-core chip doesn’t help a whole lot for gamers. If you’re serious about gaming on the go, but won’t mind turning down graphics settings, I think the A10 series will be the way to go. The A9, A6 and E2 processor families are all destined for super-cheap, affordable computing, and probably won’t satisfy the needs of power users.
Finally, AMD also doesn’t want anyone to forget that it occasionally bundles games with its products. You only get a choice of one free game with your purchase of a Bristol or Stoney Ridge APU system, so definitely get DiRT Rally if you’re buying into the more expensive chips.
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