X670 / X670E Explained – PCIe Gen 5, DDR5, Cooler Mounting Problems…

There is a lot to talk about with these new AM5 motherboards, including the fact that there are now two different options when it comes to X670 and even B650 motherboards, the “E” or “Extreme” variants – so let’s get straight into it. The most obvious change here is that AMD is dropping its long standing support for having easily bendable pins on the backs of their CPUs, instead moving them into the socket instead. Ok jokes aside AMD has moved from it’s PGA or pin grid array style chip, to LGA or land grid array, much like Intel. They’re calling the 1718 pin socket ‘AM5’, although have decided to maintain cooler compatibility – although more on that later.

The new socket is pretty huge. It’s 18 more pins than Intel’s current LGA1700 socket, although remains square unlike team blue. It uses the same swing out retainer design as you’d be used to from Intel, although it’s a complete pin array rather than Intel’s approach of keeping the pins and pads away from directly under the cores with a big hole in the middle.

The cooler compatibility is a big thing, but somewhat ironically in trying to keep everything compatible, they’ve kind of made it worse twice over. First off, AMD has always provided a backplate with its motherboards. It’s a great feature, and they haven’t stopped now. The problem comes if you use a cooler that decided to not use AMD’s provided backplate, because now you have no other option. The socket actuator mechanism – the retainer – is bolted to the same backplate they expect your cooler to use. Sounds great, right? Well, if you want to use a different backplate… Good luck installing your chip if you can’t hold it down. If you need to use a different backplate for your cooler, you’ll need an adapter kit for sure.

The other problem with the cooler compatibility is something Derbauer talked about in his great delidding video you should definitely go check out, which is that AMD decided to maintain the same Z height – how high the top of the chip is off the motherboard. This again sounds great right, it means you don’t need an adapter kit for your cooler… Except it means the IHS – the integrated heat spreader – is way too thick, meaning heat does escape the chip nearly as well as it could if the IHS was considerably thinner. This is a problem for AMD as it’s not something they can fix without breaking cooler compatibility and likely launching a new socket to make it clear which chips have a lower height. We will just have to see what AMD decides to do going forward.

Something else that’s new is DDR5 support. Unlike Intel though, AMD isn’t supporting both DDR4 and DDR5 on these chips, so to use these you’ll have to bite the bullet and buy the slightly more expensive DDR5. I say slightly because wow the pricing and availability has gotten a lot better since Intel launched their 12th gen chips. Seriously, it’s maybe £10 more for a DDR5 kit instead now. That’s not bad! Still, you will need new RAM to use these, unlike team blue’s current AND upcoming options.

But by far the weirdest new feature has to be this. The dual chipset chips. Now AMD is no stranger to “chiplet” style designs – the very CPUs that fit in these have one or two core dies onboard acting as one – but this is new at least in the consumer space. These are two of the same chips – I checked – and they are basically daisy-chained together to allow for a lot more stuff to be crammed in. I should start by also adding that these new Ryzen 7000 series CPUs not only support PCIe Gen 5, but offer an extra 4 lanes connected directly to the CPU compared to last gen. There are now 24 total lanes available for graphics and storage, all of which run at the new Gen 5 speeds. Dayum, that’s a lot of bandwidth. This generally manifests as one X16 slot connected to the CPU for your CPU, and up to two M.2 SSD slots also capable of Gen 5 speeds too.

The CPUs then have a further 4 PCIe Gen 4 lanes available to connect to the chipset, which is then further split out to a varying collection of PCIe and NVMe slots, WiFi, 2.5G ethernet and USB ports. Oh and that’s on top of the CPU also offering up to 5 USB ports, audio and technically three if you include the USB C/DisplayPort ALT Mode video outputs too. One limitation of this setup is the fact that now two chipsets have to share the same PCIe Gen4x4 link – so a single fast Gen4x4 SSD would max that out leaving no bandwidth for your WiFi or ethernet, SATA drives or USB ports. With that said, you have two PCIe Gen 5 NVMe slots available, so why on earth you’d be maxing out your chipset bandwidth is completely beyond me.

Realistically all this bandwidth is just way too much for most people to make use of – but AMD knows that. That’s why X670 ‘non-E’ exists. That does still offer one Gen 5 NVMe SSD slot, but only runs gen 4 to the other M.2 and your GPU. It does still use two chipset dies though, although they are a little lighter on I/O generally too. In theory that’s to help with cost, although the cheapest X670 board I can find is still an absolutely eye watering £270, with this Asus X670E-Plus WiFi board I have here retailing for a heart stopping £450. I’m.. I’m just gonna need a minute to process that.. £450??? AND THIS ISN’T EVEN HIGH END! Asus’s Hero board, you know the one that used to be their middle ground everyone-should-buy-this board, that’s now £650! That’s more than most graphics cards now! You can almost buy a 3080 12GB for that!

Part of that cost comes from the complexity of these new boards. All the PCIe lanes they have to route, and importantly, shield. Gen 5 runs astonishingly fast, so fast in fact that Asus had to put these Phison retransmitter chips to boost the signal and maintain its integrity over the miniscule distance between the CPU and the top PCIe and M.2 slots. I can’t find a price quote for these, but these chips alone are likely to be a quid or two. Just in op amps, mosfets and driver ICs Asus has to be dropping like £50 or £100 per board, and that’s not counting TWO of AMD’s chipset dies, heatsinks, I/O ports, and everything else. And that’s just the parts cost, not designing the boards or manufacturing 8, 10, 12 layer PCBs and assembling all this on top.

One of the other things that’ll be adding to the cost is the VRM designs. This TUF board is sporting what would have been top of the line 14+2 phase 70A VRMs just a generation or two ago, but is now middle of the road with the top end pushing 20+2 110A setups instead. That’s thanks to the increased 170W power limit on the higher end chips, up from 142W previously.

So, all in all these are some hefty boards, both in capabilities and in price. The more budget friendly B650 and B650E boards will be coming soon though, so if you’d rather not pay more than some people’s first car for a motherboard, maybe hold off for now. Plus, Z790 is inbound too, and who doesn’t love a bit of competition?