The focus for AMD’s AM4 platform is to span a wide range of performance and price points. We’ve had the launch of the Ryzen CPU family, featuring quad cores up to octa-cores with the new Zen microarchitecture, but AM4 was always designed to be a platform that merges CPUs and integrated graphics. We’re still waiting for the new Zen cores in products like Ryzen to find their way down into the desktop in the form of the Raven Ridge family, however those parts are going through the laptop stack first and will likely appear on the desktop either at the end of the year or in Q1 next year. Until then, users get to play with Bristol Ridge, originally released back in September 2016, but finally making its way to retail.
First the OEMs, Now Coming To Retail
Back in 2016, AMD released Bristol Ridge to OEMs only. These parts were the highest performing iteration of AMD’s Bulldozer design, using Excavator v2 cores on an AM4 motherboard and using DDR4. We saw several systems from HP and others that used proprietary motherboard designs (as the major OEMs do) combined with these CPUs at entry level price points. For example, a base A12-9800 system with an R7 200-series graphics card was sold around $600 at Best Buy. Back at launch, Reddit user starlightmica saw this HP Pavilion 510-p127c in Costco:
$600 gets an A12-9800, 16GB of DDR4, a 1TB mechanical drive, an additional R7 2GB graphics card, 802.11ac WiFi, a DVDRW drive, and a smattering of USB ports.
Initially AMD’s focus on this was more about B2B sales. AMD’s reasoning for going down the OEM only route was one of control and marketing, although one might suggest that by going OEM only, it allowed distributors to clear their stocks of the previous generation APUs before Ryzen hit the shelves.
Still, these were supposed to be the highest performing APUs that AMD has ever made, and users still wanted a piece of the action. If you were lucky, a part might pop up from a broken down system on eBay, but for everyone else, the question has always been when AMD would make them available through regular retail channels. The answer is today, with a worldwide launch alongside Ryzen 3. AMD states that the Bristol Ridge chips aren’t designed to be hyped up as the biggest thing, but fill in the stack of CPUs below $130, an area where AMD has had a lot of traction in the past, and still provide the best performance-per-dollar APU on the market.
The eight APUs and three CPUs being launched f spans from a high-frequency A12 part to the A6, and they all build on the Bristol Ridge notebook parts that were launched in 2016. AMD essentially skipped the 6th Gen, Carrizo, for desktop as the Carrizo design was significantly mobile focused (for Carrizo we ended up with one CPU, the Athlon X4 845 (which we reviewed), with DDR3 support but no integrated graphics). Using the updated 28nm process from TSMC, AMD was able to tweak the microarchitecture and allow full on APUs for desktops using a similar design.
AMD’s new entry-level processors will hit a maximum of 65W in their official thermal design power (TDP), with the launch offering a number of 65W and 35W parts. There was the potential to offer CPUs with a configurable TDP, as with previous APU generations, however much like the older parts that supported 65W/45W modes, it was seldom used, and chances are we will see system integrators stick with the default design power windows here. Also, the naming scheme: any 35W part now has an ‘E’ at the end of the processor name, allowing for easier identification.
Back when these CPUs were first launched, we were able to snag a few extra configuration specifications for each of the processors, including the number of streaming processors in each, base GPU frequencies, base Northbridge frequencies, and confirmation that all the APUs launched will support DDR4-2400 at JEDEC sub-timings.
The A12-9800 at the top of the stack is an interesting part on paper. If we do a direct comparison with the previous high-end AMD APUs, the A10-7890K, A10-7870K and A10-7860K, a lot of positives end up on the side of the A12.
The frequency of the A12-9800 gives it a greater dynamic range than the A10-7870K (having 3.8-4.2 GHz, rather than 3.9-4.1), but with the Excavator v2 microarchitecture, improved L1 cache, AVX 2.0 support and a much higher integrated graphics frequency (1108 MHz vs. 866 MHz) while also coming in at 30W less TDP. The 30W TDP jump is the most surprising – we’re essentially getting better than the previous A10-class performance at a lower power, which is most likely why they started naming the best APU in the stack an ‘A12’. Basically, the A12-9800 APU will be an extremely interesting one to review given the smaller L2 cache but faster graphics and DDR4 memory.
One thing users will notice is the PCIe support: these Bristol Ridge APUs only have PCIe 3.0 x8 for graphics. This means that most X370 motherboards that have two GPU slots will leave the second slot useless. AMD suggests moving to B350 instead, which only allows one add-in card.
The Integrated GPU
For the A-series parts, integrated graphics is the name of the game. AMD configures the integrated graphics in terms of Compute Units (CUs), with each CU having 64 streaming processors (SPs) using GCN 1.3 (aka GCN 3.0) architecture, the same architecture as found in AMD’s R9 Fury line of GPUs. The lowest processor in the stack, the A6-9500E, will have four CUs for 256 SPs, and the A12 APUs will have eight CUs, for 512 SPs. The other processors will have six CUs for 384 SPs, and in each circumstance the higher TDP processor typically has the higher base and turbo frequency.