Installing the CPU
We start with the CPU installation, and it turns out Ryzen's AM4 socket is different enough from Intel's most recent products that we had to dig into the manual to make sure we were doing this all right. First point of confusion: the Ryzen CPU installs sideways. We really couldn't believe that AMD would have its board partners orient the socket in such a fashion, so we checked and checked again to make sure this was indeed the intended approach. We're sure that more than a handful of users are going to try to install their Ryzen CPUs with the Ryzen branding right-side up. Luckily, the CPU's pins won't allow the CPU to drop into the socket in that orientation, but there's still a chance that they can be accidentally bent in the attempt. Note that the AMD pin design is the reverse of Intel's: the pins are on the CPU, rather than the socket, and luckily they are a lot less easy to damage than Intel's flexible socket pins.
In the photos above, you can first see the locking bar in the unlocked position, and then you see the Ryzen CPU dropped into the socket. In the last photo, the bar is dropped down into the locked position. Interestingly, this lock isn't so much a lock as a switch; the bar simply slides the CPU into position. As we found out the hard way, it doesn't actually lock the CPU down: when we went to swap out our cooler, the CPU lifted right up out of the socket with the cooler, having adhered to its base as a result of the bond formed by the thermal paste applied to it. To prevent this, you need to twist the cooler off to break the seal between it and the CPU heat spreader.
Speaking of CPU coolers, let's dive into how that installation works on Ryzen.
Installing the CPU Cooler
What you can see in the first photo above is our CPU locked into place, flanked on either side by the stock AMD heatsink mount. Because AMD didn't send along a sample of its Wraith cooler, we had to go aftermarket, but luckily Noctua had set us up in advance of the Ryzen launch with its best gear. In place of the AMD mount went Noctua's new NM-AM4 conversion kit, shown below, which as with all Noctua products comes packaged beautifully.
To use the Noctua mount, we had to remove the stock AMD mount. This is a process Intel users will not be familiar with, as there is no removable mount on the Intel platform; cooler manufacturers must provide it themselves. We have to applaud AMD for providing the mount, as it allows CPU cooler installation without the need to access the back of the motherboard. And just like the standard AMD AM4 mount, the NM-AM4 screws right in, without requiring access to the back of the motherboard. Strangely, though, that the screws were a little longer than we expected and stuck out the back of the motherboard by a few millimeters. No harm was done, but we wonder if those screws might touch the back panel in very compact cases (e.g., in mini-ITX systems). Once the bracket was in place, we applied Noctua NT-H1 thermal paste, using a bit more than we have with Intel's Skylake and Kaby Lake CPUs due to the larger heat spreader on Ryzen.
Below you can get the full picture of what a Ryzen processor looks like mounted in our Gigabyte GA-AB350-Gaming 3, with a bonus view of our Samsung SM951 PCIe drive installed in the PCIe 3.0 x4-compatible M.2 slot.
Finally, we lower the big Noctua NH-D15S into position, affix the two spring-loaded screws, and attach the 140mm fan. Note that we also tried Noctua's premier NH-D15 SE-AM4, which comes pre-packaged with the AM4 mount, but we found that it was simply too big. Unlike the NH-D15S, it has two fans, and its front-mounted fan blocked our RAM slots, requiring the fan to be raised way up, and even then it meant the sweet white LEDs on our GeIL RAM (which we'll show off on the next page) couldn't be seen. Even worse, it nearly covered the second PCIe slot (the first one was completely covered), meaning it was way too close for comfort to our Radeon R9 Fury video card. We decided to fall back on the NH-D15S, which features an ingenious offset to shift it upwards on the motherboard and away from the PCIe slots. It comes with just one 140mm fan, but that's honestly plenty. The second fan doesn't add that much performance to this cooler, as we found in our Noctua 140mm Cooler Shootout. Just keep in mind that the NH-D15S is not being sold as an AM4-specific model, so you'll need the Noctua NM-AM4 kit to use it.
The final step was to install the video card. As there's nothing unique about installing a video card on an AM4 board, we'll just take the opportunity here to discuss the difference between X370 and B350 boards when it comes to handling video cards. The X370 chipset offers up two PCIe 3.0 x16 slots, which can support dual video cards in either SLI or CrossfireX running at PCIe 3.0 x8 speeds. The B350 chipset, on the other hand, provides only one PCIe 3.0 x16 slot, with the other full-size slot being of the PCIe 3.0 x4 variety. This will support CrossfireX at reduced speeds, but Nvidia does not allow such arrangements to be certified for SLI use, so SLI is out of the question on the B350 chipset. As we're testing just a single Radeon-based card, neither of these limitations were of concern to us in choosing the well-priced B350 board we purchased as a replacement for our defective Asus X370-based board. Keen observers will note that the Noctua cooler pictured above is actually mounted on the Asus ROG Crosshair VI Hero. Yes, we really did go through the painful process of testing this board only to find that it had a failed memory channel!
We want to end the discussion of the build process with one more important note related to graphics: you will find that most AM4 motherboards have video output connectors, but Ryzen CPUs do not have built-in graphics processors. These outputs will therefore be non-functional when used with any Ryzen CPU. This is not a massive goof up on the part of motherboard manufacturers; in fact, the boards are designed to do double-duty, with support for AMD's forthcoming next-gen "APUs". This different category of chip combines Radeon graphics into the CPU. With these processors, the motherboard outputs will of course be fully functional.
OK, now we're ready to get the guts of the system installed into our case. Turn to the next page to see how it all comes together.