AMD Ryzen 7 1800X review

Although AMD never stopped selling processors for desktop PCs, it has felt an awful lot like it did for the last few years. Intel has so dominated the market at all levels, from budget machines right up to the most expensive enthusiast rigs, that there was really no point in choosing a PC with an AMD processor. We won’t go into it here, but you can read more about AMD’s history.

But with the launch of Ryzen, that has all changed. We’ve reviewed the range-topping 1800X here, along with the cheaper 1700, but two even cheaper Ryzen 5 chips which are launching in a couple of months. See also: Ryzen release date, price and specifications

Update 15 March: We’ve now added the benchmark results from the Ryzen 7 1700 to our graph below. Plus, AMD has made an official comment on the Ryzen 1800X (and 1700X) temperatures – read more.

AMD Ryzen review: Price

Here’s how the range looks at the moment, but AMD will add more models over time. You can buy the three Ryzen 7 chips from Overclockers UK. Most come with one of AMD’s three new CPU coolers, but not the top two models. It’s assumed you will have your own already, or want to use a high-end liquid-cooling system. It’s worth noting, too, that AM3 and FM2+ “clip style” coolers are compatible with Socket AM4.

Note: These chips are not APUs like AMD’s other A-series CPUs. This means that they do not have built-in graphics chips.

AMD Ryzen review: Features and design

Four years ago AMD realised it needed to completely redesign its CPU in order to compete with Intel, and began developing what we now know as the ‘Zen’ architecture.

The Ryzen 7 1800X is the current flagship consumer CPU based on Zen, and is an eight-core processor that runs at 3.6GHz (up to 4.1GHz with a suitable cooler – more on this later).

AMD has gone down the same route as Intel and now uses Simultaneous MultiThreading (SMT) rather than the Clustered MultiThreading (CMT) that its older processors used.

We’re not going to go into the deep technical details here because what really matters is whether the Ryzen 1800X and 1700 are good value, and whether you should buy one or other of them.

But before we do that, we need to explain a few other things about the new features AMD has put into Ryzen.

AMD Ryzen review: Socket AM4

First, Ryzen is not going to fit into any existing AMD motherboard. That’s hardly surprising, given that this is truly a “clean-sheet” design. So you’ll need a new motherboard which has an AM4 socket with 1331 pins.

AMD says you’ll be able to upgrade processors with an AM4 socket until 2020, barring any technology advances which require a physical change to the pinouts, such as PCI Express 4 or DDR5 RAM.

Ryzen is more of a system-on-a-chip (SoC) like smartphone processors, which means the actual chipset on an AM4 motherboard is relatively basic.

There are eight to choose between, but the most common are likely to be the B350 and X370. The former is the more mainstream offering which allows overclocking, while the latter is aimed at enthusiasts who want the maximum number of features on their board.

These new boards, such as the Asus Crosshair VI Hero X370 that we used for testing the chips, have the latest features such as PCIe gen 3, an M.2 slot for the latest NVMe SSDs, USB 3.1 gen 2 ports and support for DDR4 RAM.

Ryzen CPUs have a total of 24 PCIe lanes. This isn’t as many as Intel’s top chipsets offer, but it’s enough. 16 lanes are dedicated to the graphics card, and the rest are for the motherboard maker to use for I/O and things such as NVMe SSDs.

If you do go for an X370 motherboard and want to run dual graphics cards, note that each will have to use 8 PCIe lanes.

Similarly, if you must use multiple NVMe drives simultaneously, you may be better off with Intel’s Broadwell-E and the X99 chipset. But you’d better have deep pockets, as such as setup does not come cheap.

This, ultimately, is where Ryzen delivers its knock-out blow: for the vast majority of PC enthusiasts, the Ryzen 7 chips offer plenty of performance, along with great efficiency, at a much lower price.

AMD Ryzen review: SenseMI

One of Ryzen’s really clever features is a grid of super-accurate sensors across the silicon which act much like the telemetry on an F1 car. They feed back power and temperature data so that the chip can adjust its speed based on conditions.

SenseMI is the name for a group of five technologies which AMD says ultimately give Ryzen the edge.

Precision Boost: Using the sensors, the chip can finely adjust its speed on the fly in 25MHz increments. It will increase or decrease speed based on temperature, load and current.

Pure Power: Similar to the boosting, the same sensors are used to adjust the CPU’s power consumption for a given task. Since each chip is very slightly different from every other at the silion level, the data from the sensors means each chip can optimise its power usage individually.

Extended Frequency Range (XFR): Only Ryzen chips with model numbers ending in ‘X’ support XFR. This is basically automatic overclocking and allows the chip to boost beyond the usual top frequency if the data from the sensors show that there is ‘headroom’ to run faster. Essentially, if you have a good cooling system which keeps temperatures down, you’ll see an extra 100MHz, so 4.1GHz instead of 4GHz with a Ryzen 1800X.

Neural Net Prediction: This is an artificial intelligence neural network that learns to predict what an application will do based on past runs, and queues up instructions so they can be executed quicker.

Smart Prefetch: Pretty much the same as neural net prediction, but for data rather than CPU instructions. Sophisticated learning algorithms track software behaviour to anticipate what data will be needed, and load it into the Ryzen’s caches so it’s ready when called for.

AMD Ryzen review: Performance

But enough about features and technology. The bottom line is: how fast do they go?

The short answer is fast, and certainly in line with AMD’s claims. Intel hasn’t released an eight-core Kaby Lake processor yet, which is why the main comparison is with the Core i7-6900K. The i7-7700K is the top Kaby Lake chip right now, and that’s a quad-core, eight-thread chip. It’s also the same price as the Ryzen 7 1700, which has the full complement of eight cores, 16 threads.

The 1800X isn’t always faster than the i7-6900K, so in pure performance terms, AMD hasn’t conclusively stolen the crown from Intel. But if you look not at absolute speed, but bang-per-buck, you’re getting what amounts to basically the same performance in most scenarios for half the cash.

The step-down Ryzen 7 1700 isn’t as quick as the 1800X of course (aside from a couple of anomalous results) but thanks to the fact it has twice the core count of the i7-7700K it soundly beats it in tests which can use all those cores. When they can’t – and specifically in single-threaded tests – the i7-7700K is a good margin faster.

This fact will undoubtedly force Intel to make big price cuts to its six- and eight-core CPUs, and we’re already hearing rumours that it has already done so. We’ll have to wait a bit until we see retailers passing on the savings, though.

Single-core performance isn’t where Ryzen’s strength lies: it’s roughly on a par with Intel Haswell chips (not Skylake or Kaby Lake), but as soon as you use an application or game which can use Ryzen’s large number of cores, it accelerates away from any same-price chip from Intel (and matches those costing a lot more). You can see this illustrated in the Geekbench results below – an overclocked Core i5-7600K is faster than a stock Ryzen 1800X in the single-core test, but the Ryzen kills it in multi-core. Also, note the massive lead that Ryzen holds in the Cinebench rendering test.

The graphs below show how the Ryzen 1800X and 1700 stack up against the most recent Kaby Lake PC we’ve reviewed, the Overclockers UK Titan Bayonet. This uses an i5-7600K overclocked to 4.7GHz on air and a GTX 1070. The closest comparison is between the 1800X and the i5-7600K because both systems cost a similar price (around £1600). Note that our rig had a GTX 1080 rather than the Bayonet’s 1070, but the results below focus on CPU, not GPU, performance.

Our colleagues at our sister title PC World benchmarked the same two Ryzen chips against Intel’s top chips (the systems here are fitted with 32GB of RAM and GTX 1080 graphics cards – read more and see more test results here).

Most of the results above are self-explanatory, and are what we would expect. However, in many games right now it seems that you will get better performance if you have a high-end Intel chip. AMD says this is down to the fact that games are currently optimised for Intel processors, but developers are working to optimise for Ryzen as quickly as they can to take full advantage of the extra cores and threads on offer. 

But, you have to bear in mind that the Ashes of the Singularity test was run at 1080p at low quality settings in order to look at CPU performance and take the GPU out of the equation. In the real world, you’re not going to do that, and the Tomb Raider results – at Ultimate quality – show that all you’ll get very similar results regardless of which of these four CPUs you have.

Overclocking

In theory you should be able to get even more performance for free by overclocking a Ryzen chip. This is something AMD has been keen to point out at every opportunity: all Ryzen chips are unlocked and, when paired with the right motherboard, can be overclocked at will.

There’s even a new tool, Ryzen Master, which you can download and use to set up four different overclocking profiles. Of course, you’ll have to agree to the big disclaimer that you’ll void your warranty if you do overclock as there is potential to damage the chip and other hardware if you don’t know what you’re doing (or if you push frequencies or voltages too high).

We couldn’t do much with our air-cooled system, being supplied with a Noctua NH-U12S by AMD for testing. Still, we did see XFR in action on occasion, with the frequency jumping to 4.1GHz in CPU-Z while temperatures were low enough.

However, the chip was reluctant to go much beyond this and we suspect you’ll need a liquid cooling system to get the most from Ryzen. It runs fairly hot even when idling, sitting around 60 degrees C with the Noctua, and an additional 120mm fan extracting hot air from the case. Update: AMD has explained that the 1800X and 1700X report a temperature 20 degrees C higher than their actual temperature. This is in order to ensure the processors have a “consistent fan policy”. Whatever that means, it does reassure us that that there isn’t an issue with running too hot at idle. 40-odd degrees is pretty normal for a CPU, and that’s roughly what we saw when testing the Ryzen 7 1700. Monitoring utilities will no doubt be updated to display the correct temperatures, but it’s strange that AMD’s new Ryzen Master tool also reports the ‘wrong’ temperature.

The bottom line here is that Intel chips – in PCs we’ve reviewed recently – appear to be more accommodating to overclocking on air cooling, but we’ll run more tests, including on the Ryzen 7 1700 before we can make an absolute judgement on this.