AMD has been talking a lot during the last few weeks about their new CPU platform Zen, and it even has a name now that it is thoroughly corny and cheesy: “Ryzen”. It’s intended as a play on AMD’s new slogan, “New Horizens”, but it’s going to be used everywhere on the internet as a pun for AMD’s comeback to the CPU space. Is this viral marketing at work here? Probably. It’s working either way. Since we’ve just opened up after our holiday break, I’d like to hit you up with a recap to start off your week. Zen is coming!
Ryzen, a new core architecture
If you’ve been following my coverage on AMD’s Zen architecture, then you’ll know that there’s every reason to be excited for it. For those of you who haven’t, it’s a grounds-up design created by Jim Keller and his team of engineers at AMD, designed to work around issues present in AMD’s two recent major architectures, and optimise the flow of information and instructions as much as possible. Zen’s design follows some of the same techniques introduced by Intel, but it’s very much its own thing.
AMD plans to launch Zen in the first quarter of 2017, with a full complement of chips to choose from, as well as a wide range of motherboards to use them on. Topping the range is Summit Ridge, an eight-core, sixteen-threaded behemoth that also boasts 20MB of cache. Pricing hasn’t been determined on these chips, but there are rumours that point to the top-end Ryzen processor shipping at the $500 price point overseas. If that’s the case, then AMD is preparing to sell a product that offers the same or better performance to a Core i7-5960X for half the price. Model numbers are also a bit of a mystery, but some websites have reported that AMD will refer to the chips as SR7, SR5, and SR3 for the quad-core variant. There’s still a lot to work out, but we won’t have long to wait.
Part of Ryzen’s special sauce will be an improved prediction algorithm that tries to model what a workload will entail in order to optimise its execution, without needing gobs of cache to store the data in. We’ve already had branch prediction like this in CPUs for decades, but AMD wants to take it further and try to anticipate what the likely outcome is going to be before the chip chews through anything with an op-cache and a micro-op cache built using a history of software that’s been executed in the past. Neural branch prediction is beneficial only to reduce the chances of mistakes made in branch prediction, so this will blow the socks off a Bulldozer core, but it might only be as good as Intel’s branch prediction in their modern architectures.
Ryzen is also complemented by new silicon processes, and AMD is taking advantage of this through fine-grained voltage and clock speed control. We’ve had this before in a cruder fashion in AMD’s APUs starting with the Richland family implementing resonant clock mesh (RCM). In short, this is method to preserve performance and conserve power by power gating parts of the CPU that aren’t required at the time. RCM also saw use in improving the GPU performance of those chips, because the CPU and GPU portions had to share the same TDP, and any upswing in a graphical workload was often met by the CPU being underclocked.
Instead of stepping the voltage and frequency in large increments, there are now smaller steps at 25MHz that make the power curve easier to control. This might benefit the desktop platform in a neat way, but it’s going to have a bigger impact in the mobile space when Ryzen reaches laptops.
Finally, extended frequence range (XFR) will be an optional ability that can be turned off in the CPU BIOS that will automatically overclock the chip so long as thermal limits are maintained and controlled. The CPU will have enough sensors and information to feed back into the power and precision boost mechanisms, allowing the clock speed to run as high as possible so long as the chip stays cool. This might not be a fun idea for the enthusiasts who will run their extreme cooling systems for more power for benchmarks, but for the average user it will be interesting to see how high the chip is allowed to go under a decent all-in-one water cooler.
For those of you wondering why this needs to be a thing at all, consider that AMD is shoving an entire platform into a single package. The chipset is on there as well as the northbridge, the memory controller, and all manner of logic that isn’t always related to whatever the CPU is doing. Overdoing an overclock may damage any one of these things, and the tolerances to which they’re designed might not be taken into account if someone without a lot of experience pushes things too far.
A new high-end chipset, the X300 series
AMD’s chipsets are now embedded into the CPU package, which makes it count as a system-on-chip design. This technically means that the motherboard is no longer in charge of exposing overclocking features, although there are still boards that will have the designation “X370” to denote which ones are designed for overclocking Zen processors, and which ones aren’t. A benefit to this is that a Zen CPU can fit into any socket AM4 system, even if it’s a A320 motherboard, and it isn’t likely to run into the same exploit that Skylake processors did with a rogue BIOS from vendors that allowed overclocking Core i3 CPUs.
The lineup is pretty simplistic. If you want overclocking, either pick up an X300-series ITX motherboard, or an X370 motherboard in the mATX or ATX form factors. If you just want the basics with the possibility of some tweaking, a B350 board will be for you. The only thing that puzzles me is the lack of USB 3.1 support on the small form factor platforms. I suppose a third-party chipset might be used on those motherboards.
Also note the line at the bottom: every AM4 processor is multiplier unlocked. That means that every APU based on socket AM4 can be overclocked, as well as any Ryzen CPU available. That is a major departure for AMD, and a big selling point against competing chips from Intel. I can see a lot of people picking up an A12-9830 APU for a simplistic tower costing around R5,000.
Storage-wise, there are quite a few options available for the AM4 platform. Ryzen can handle up to four NVMe solid state drives in one system, where the most Intel could manage on the Z170 platform was three. Memory support is limited to two channels, but that’s just fine. Any extra ports or connectivity beyond the features listed in this table will be provided by third-party chipsets, so you can expect to see a motherboard boasting a Marvell SATA controller to allow RAID on those extra ports. SLI or Crossfire is also limited to the X370 chipset, which makes things all the more simpler.
I’m somewhat concerned about the USB setup, however. I’m certain that the setup noted in the table is not in error, so that means that USB 3.1 Gen 2 support is achieved through teaming the chipset lanes reserved for the USB 3.1 Gen 1 ports together. Motherboards boasting Gen 2 support will therefore only have two such ports available, and the motherboard vendor may have to use a third-party chipset to offer more USB connectivity. Since there’s also no USB 2.0 provisioned either, that might end up being the case for almost every motherboard out there. Hopefully the next iteration of Zen fixes this.
Closing things off, I’d like to treat you to a gallery of the range of motherboards expected to be available at launch in the coming months. These products have been in AMD’s hands for some time, no doubt, and the vendors must have been itching to get them out. The cooler mounts on these boards are not compatible with older mounting solutions, so those of you who’ve kept a Danger Den water loop running from the socket 939 days will have to wait until a new mounting bracket is made for it. At launch, these motherboards are expected to be available almost worldwide:
- ASRock X370 Taichi
- ASRock X370 Gaming K4
- ASRock AB350 Gaming K4
- ASRock A320M Pro 4
- ASUS B350M-C
- Biostar X370GT7
- Biostar X350GT5
- Biostar X350GT3
- GIGABYTE AX370-Gaming K5
- GIGABYTE AX370-Gaming 5
- GIGABYTE AB350-Gaming 3
- GIGABYTE A320M-HD3
- MSI X370 XPower Gaming Titanium
- MSI B350 Tomahawk
- MSI B350M Mortar
- MSI A320M Pro-VD
Feast your eyes on the gallery below!