AMD Ryzen R7
BENNETT RING is happy to finally see some CPU competition
Thank you AMD. It might have taken four years to go from the drawing board to churning chips out on the factory line, but your new Ryzen CPU is hopefully going to do wonders for PC gaming. You see, we’ve been bored out of our skull with the monopoly that Intel has had for the last five years when it came to CPU performance, especially when it came to games. But in one fell swoop you’ve managed to deliver a brand-new CPU that promises to reignite the CPU wars, finally challenging Intel’s dominance and spurring them into action to lift performance by more than a few digits each year.
Well, that’s the plan with Ryzen. Unfortunately the story about this chip’s performance isn’t such a straight tale – while it does whip Intel into shape in certain scenarios, when it comes to pure gaming grunt, it’s not quite the be all and end all we expected. Before we look at the reasons why, let’s examine the initial three launch chips, and take a look at what’s underneath that heat spreader.
A WORKSTATION MONSTROSITY
At the heart of all of the new Ryzen chips is AMD’s shiny new Zen architecture. And when we say new, we really mean it – there’s none of the piddly little updates we’ve grown accustomed to over the last half decade. AMD went back to basics with the design of this x86 chip, focusing on improving raw Instructions per Cycle, or IPC. This is basically how much work each core in the CPU can handle, and it’s an area where Intel has traditionally lorded it all over AMD for so long.
The initial design goal for Zen was to hit a 40% IPC performance increase, all while maintaining low power usage. AMD didn’t manage to this increase though… they beat it. In some cases, the new Zen architecture is up to 52% faster than its previous core architecture, making it quite possibly the biggest single leap in core performance we’ve ever seen, and bringing it within spitting distance of Intel’s chips.
AMD has launched three new Ryzen chips to begin with, and they’re all eight-cored beasts. At the high-end we have the Ryzen 7 (aka R7) 1800X. This eight-cored chip is designed to take on Intel’s eight-cored i7-6900K, but at half the price, costing a mere $699 versus $1500 for the Intel chip. It has a base frequency of 3.6GHz, which then boosts to a guaranteed
Turbo speed of 4GHz. However, there’s still a little more headroom thanks to the X on the end of the product name, which means this chip is endowed with XFR, or Extended Frequency Range. In the right thermal conditions, this can add an additional 100Mhz to the chip, in 25MHz increments, promising a top speed of 4.1GHz.
Next up is the R7 1700X, and it’s basically identical to the 1800X bar some slight speed drops. Base speed is lowered to 3.4GHz while Boost hits 3.8GHz, and it too features XFR. At just $569, it’s considerably cheaper than the 1800X, while not missing out on much of the performance. Finally we have the budget model, and this is the one overclockers are most excited about. The R7 1700 again is functionally identical
to the other two chips, though it doesn’t have XFR. The frequency has also dropped, down to 3GHz at base and 3.7GHz for Boost. Yet there are a plethora of online overclockers who have easily hit 4GHz with this chip, putting this $469 baby on par with the top of the line R7 1800X. By the way, all three chips are multiplier unlocked, allowing for simple overclocking. The top-end R7 1800X isn’t much of an overclocker though, with our sample maxing out at 4.1GHz.
There are also three new coolers for use with these chips, though the two most expensive CPUs don’t include one at all. There’s the topend Wraith Max (38dBa), mid-range Wraith Spire (32dBa) and finally the Wraith Stealth (28dBa), but none of these were available at the time of our review. Instead AMD sent us a Noctua NH-U12S SE-AM4 for use during our testing. Only the R7 1700 comes with a cooler, in the form of the Wraith Spire. They all utilise a new spring-screw clamping mechanism, and also feature an RGB ring around the top. The good news is that many existing coolers will work with the new socket design, as the likes of Corsair, Thermaltake and Noctua are either providing free adaptors, or charging a minimal $20 cost for a clip upgrade kit.
Speaking of the new socket, all Ryzen chips are now using the latest AM4 socket design, which fits in the new pin count of 1331 pins. AMD has stuck with its usual pin-on-CPU design, as opposed to Intel’s reverse design, where the pins are mounted in the socket. Each CPU is comprised of 4.8 billion transistors, and they’re built using GloFo’s 14nm FinFET process, which has allowed AMD to deliver exceptionally good TDP numbers for each chip. The top two hit 95W, while the 1700 maxes out at just 65W, provided you don’t overclock it. This small manufacturing process also means that they chips are relatively small, with a die size of just 192 square millimetres, which makes them more affordable to build.
our benchmarks show that the Zen architecture hasn’t quite caught up to Kaby Lake
WHAT MAKES ZEN TICK?
At the heart of Zen are its new CCX Modules, aka CPU Complex. Each of these has four CPU cores, 64kb of L1 I-cache, 64kb of L1 D-cache, 512KB of L2 cache per core, and 8MB of L3 cache shared across all four cores. The R7 processors all use two of these CCX modules, hence why they deliver eight cores with a total of 16MB of L3 cache. By going with this format, it’ll be easy for AMD to deliver a quad-core version, which is known as the X5. More about that later.
While Ryzen is an eight-cored CPU, it actually can handle up to 16 threads.
this is because aMD has implemented a technology that is very similar to intel’s hyperthreading, but which it calls sMt, or simultaneous Multithread. it’s taken a slightly different approach to intel though; intel uses joint schedulers and buffers to enable its support for twin threads per core, while zen has independent dual schedulers, one for int and the other for floating Point.
the other major reason for the leap in iPc performance is known as senseMi. this is basically an umbrella term for five different technologies that make use of over 1000+ sensors embedded within the cPu. every millisecond, they check the frequency, temperature and power usage of various components within the cPu. this way it can automatically boost voltage to areas where it’s needed most, while also cutting power where it’s not needed. this allows cPu to operate at maximum frequency when required, and then power down when it’s not, delivering both performance while also lowering power usage.
One of the other key changes to the CPU is improved branch prediction and pre-fetch, covered by the ‘Neural Net Prediction’ and ‘Smart Prefetch’ technologies. This basically allows the CPU to predict the future, and keep instructions that it thinks are going to be used on a regular basis in the cache, ready to roll straight away. This is hugely important when it comes to ensuring the CPU is being used most efficiently, as most applications repeat instructions regularly – by not having to reload them into the caches, the CPU can dramatically improve its overall performance. One last thing to note – none of the Ryzen CPUs comes with an integrated GPU. If you’re going Ryzen, you’re going discrete, though we can expect to see the Zen cores in an upcoming AMD CPU later this year that will include an iGPU.
CHIPSETS
Along with the new CPUs and AM4 Socket, AMD is launching three new chipsets with the initial R7 launch. The high-end is the X370, and it includes twin USB 3.1 Gen 1, six USB 3.1 Gen 1 and six USB Gen 2.0 ports, along with four SATA 3 6Gbps connections. It also has twin SATAe drive ports, which can be used as another four SATA 3 6Gbps ports. There’s another eight lanes of PCIe Gen 2.0, while the most commonly used RAID 0, 1 and 10 modes are supported. It comes with twin PCIe slots for CrossFire/SLI setups, and fully supports multiplier overclocking.
Next down the line is the B350; basically it’s the same but has fewer SUB ports, only six PCIe 2.0 slots, and a single CPU to GPU PCIe lane. The good news is that this mainstream chipset still supports overclocking. The runt of the litter is the A320; this lowers the overall number of USB ports even more, drops the number of PCIe 2.0 lanes to four, has a single CPU to GPU PCIe lane, and most importantly, ditches overclocking support.
All boards now support M.2 NVMe drives, and the official memory speed is 2666MHz, though this varies based on amount, number of sticks and whether it’s dual or single rank:
• Dual Channel/Dual Rank/4 DIMM: 1866MHz
• Dual Channel/Single Rank/4 DIMM:
2133MHz • Dual Channel/Dual Rank/2 DIMM:
2400MHz • Dual Channel/Single Rank/2 DIMM:
2667MHz
We have to say that memory support for these chipset is… lacking to say the least. It was the number one problem with testing. We used the Corsair Vengeance CMK16GX4M2B830000C15 DDR4-3000MHz kit that came with our test platform, and had many, many issues getting this to run at the default speed of 2666MHz. Every single board defaulted to 2133MHz, and after manually changing this to 2666MHz via the BIOS, half the boards wouldn’t boot, requiring massaging of the memory timings to get each board working. It’s an area that AMD really needs to improve upon urgently, as it’s the #1 issue with the platform at the moment.
There’s also one other issue – PCIe lane support. An R7 1800X paired with the X370 chipset only has 24 PCIe lanes, which almost half that of the 40 offered by the competing Intel platform. This means less support for multiple SSDs, graphics cards, USB ports and other peripherals. AMD explained that this is because these chipsets are designed for the mainstream products due later in the year, and thus need to be affordable.
WORKSTATION AMAZING, NOT SO GREAT FOR GAMING.
We compared the R7 1800X against Intel’s i7-6950X, as we couldn’t obtain an i7-6900K. However, we were able
This basically allows the CPU to predict the future, and keep instructions that it thinks are going to be used in the cache
to disable two of its ten cores, to put it on a more even path with the 1800X, though the Intel chip still has slightly more cache, at 20MB of L3 cache. We also compared it against the current king of gaming chips, Intel’s i77700K. We should point out that the 7700K uses Intel’s latest Kaby Lake architecture, while the 6950X and 6900K both use the two year old Broadwell E architecture; Kaby Lake is known to have better IPC performance.
When it came to the singlethreaded Cinebench R15 test, we can see that the 1800X has caught up to Intel’s $1500 CPU. Not bad for half the price. It’s even faster when all eight cores are in action. In fact, in every benchmark that utilises all eight cores – Handbrake, POVRay, and SiSoft Arithmetic – the 1800X beats the 6900K, and kicks the arse of the i77700k. This is fantastic news for content creators such as 3D artists, CAD users, video editors and any other power user who utilises software designed for 8cores/ 16threads. This is amazing considering AMD’s platform (CPU plus motherboard can cost as little as $700, versus
Unfortunately the story for gaming isn’t quite as rosy. The vast majority of games on the market today use just four cores, and our benchmarks show that the Zen architecture hasn’t caught up to the Kaby Lake design in the 7700k. We ran all of our gaming benchmarks at low resolution to ensure the GPU wasn’t a bottleneck, and the 1800X was beaten by the 7700K in every test, and by a relatively large margin. There’s two key reasons for this. Firstly, the 7700K has higher IPC performance, of approximately 22% according to our Cinebench R15 singlethreaded test. Secondly, the 7700K also has a frequency improvement of 10%, as it has a max Turbo speed of 4.5GHz.
So then, the Ryzen 7 isn’t quite the gaming demon we were expecting, but it certainly smashes Intel’s competing workstation solutions, which can only be a good thing. Delivering better performance than the i76900K at half the price, it’s a big win for AMD. And even though the gaming performance isn’t amazing, it’s still a nice leap up from prior AMD designs, which should light a fire under Intel to lift its game. Where things will get really interesting for gamers is the Ryzen 5, which is a quadcore CPU, and thus much more relevant for gaming.