While there is a lot of focus on the mainstream desktop market, we hastily reviewed the new entrant to the low-end socketed desktop from AMD, the AM1 Kabini platform back in April.  Since then we have acquired all four members of the family, the two quad core Athlon APUs and the two Sempron APUs, for testing.  AMD’s movement into the upgradable tablet/desktop crossover arena is an interesting one for sure.

What Is The Point of AM1?

AMD’s reason for releasing a socketed low-power platform was derived from requests in low cost areas of the market.  System integrators and companies in South America, Africa and Central Asia wanted a base system which would run an operating system which could be upgraded in the future to higher specification components, rather than sticking with a low-power but non-upgradable mobile CPU.  The end result was AM1, the name given to a system using an FS1b socket with a desktop Kabini APU and an aim to build an upgradable CPU/motherboard combination for around $60.

Typically when dealing with the low cost/low power end of the spectrum, these systems are designed such that the APU is soldered on to the motherboard. When a user wants one model in particular, it comes as part of a package, much in the same way as a mobile device. In fact we even played a small game of ‘spot the desktop Kabini’ back at Computex 2013 and saw models such as the aptly named KBN-I from ECS, using the soldered A6-5200 APU:

These systems often find their way into applications that have long upgrade cycles, such as embedded and digital signage. The novelty of an upgradeable, socketed package makes most sense in the desktop arena. With low cost segments focusing more on the entry-level segmentation, AMD believe that having this upgradeability might drive pressure in the entry market towards these upgradeable PC-like devices.

AMD is marketing the series as a cheap, low powered way to go to quad core. When building a CPU architecture there is often a point in frequency scaling which is most efficient, and any deviation from that causes a less-than-linear gain in performance for power. Under this paradigm, and the importance of single core speed, the general feeling at AnandTech is that single core performance is preferred to more cores. If we can get the same multi-core performance using half the number of cores within the same power bracket, then this solution would be preferred. The final piece of that puzzle however comes in terms of design and price, both of which are points that AMD is also aiming to be competitive.

Desktop Kabini

There are a total of four AM1 APUs on the market:

AMD AM1 Kabini APUs
  Athlon 5350 Athlon 5150 Sempron 3850 Sempron 2650
CPU Cores 4 4 4 2
CPU Frequency 2.05 GHz 1.60 GHz 1.30 GHz 1.45 GHz
GPU Cores 128 128 128 128
GPU Frequency 600 MHz 600 MHz 450 MHz 400 MHz
Memory Frequency 1600 MHz 1600 MHz 1600 MHz 1333 MHz
L2 Cache 2 MB 2 MB 2 MB 1 MB
TDP 25 W 25 W 25 W 25 W
Official Launch Price $59 $49 $39 $31

Each of these APUs features up to four 28nm Jaguar cores and a 128 SP implementation of AMD's GCN GPU. We've gone over both the Jaguar and GCN architectures in previous articles, so we won't spend a lot of time recapping them here. Jaguar is the latest in AMD's line of "cat" cores, designed to go up against Intel's Atom. GCN on the other hand is a well-known GPU design from AMD as well, cut down here to fit in a much smaller die area (and thermal envelope).

The Jaguar cores in Kabini are listed as 3.1mm2, and AMD is quoting that four of these cores will fit into a single Steamroller module. Unfortunately the dimensions of a Steamroller module are not known - a 32nm SOI Bulldozer module clocked in at 30.9 mm2 for example, but no equivalent number is available for 28nm Steamroller. However some quick math shows four Jaguar cores populates 12.4 mm2. This leaves the rest of the core for the L2 cache, IGP and a large amount of IO.

In fact there are a few images that can help us predict total die size. In AMD’s slide deck, we have the following:

Given that one core is 3.1 mm2, extrapolating out gives the size of the die at 31.4x the size of a single core, or 97.3 mm2. The GPU area is approximately 5.2x the size of a core, giving ~16.1 mm2 for 128 GCN cores, compared to 12.4 mm2 for CPU cores. The Video Codec Engine and Unified Video Decoder are not part of these totals, located on other parts of the APU. The memory controller clocks in at ~9.4 mm2 and the display/IO portion runs at ~7.3 mm2

AMD AM1 Kabini Part 2: The Competition and The Test
Comments Locked


View All Comments

  • Ian Cutress - Thursday, May 29, 2014 - link

    I've taken test data from all of my old testing as well, where I've run the same benchmarks on the same OS and SSD, hence why there are many data points to choose from. I have adjusted several of the graphs to have a narrower band of data showing to more easily see the difference now. Unfortunately the even older data (pre Core 2) is before my time at AnandTech.

    Regarding the J1800/J1900 motherboards, the two that I hurried in for testing were unfortunately limited in the GPU aspect and a third one I have since received is also in the same boat. Due to the hurried nature of getting the data from the initial release (as well as other testing on hand) I had perhaps wrongly assumed that all J1800/J1900 motherboards were in the same boat.

    I am shifting my test stations around somewhat this week, so when I come back from Computex I will have more of a low power/DRAM testing setup alongside the higher power systems I normally test. If you want to see anything specific, please feel free to email.
  • edwpang - Friday, May 30, 2014 - link

    It's definitely makes better sense than current review. As someone has already, using 1250w PS on this low end setup is kindly uselessly.
  • piroroadkill - Thursday, May 29, 2014 - link

    Truecrypt link seems like a bad idea right now, since the official Truecrypt site is in a terrible state of limbo where nobody can figure out whether it's discontinued by the devs or been hacked. Benchmarks for 7.1a are relevant, but 7.2 is a gutted, useless pile of crap. Just saying.
  • A5 - Thursday, May 29, 2014 - link

    It's good thing the bench is 7.1a then?
  • Ian Cutress - Thursday, May 29, 2014 - link

    Ha! I thought about taking the data out given that I had already uploaded almost all it before that announcement was made. However 7.1a is still viable and I still have the installer, so it might still be relevant if the installer still floats around in cyberspace. I somehow doubt we will ever get a full explanation from the developers on why they took it down, though there are many theories about it.
  • Runamok81 - Thursday, May 29, 2014 - link

    Typo, second to last sentence. platgorm
  • someeeguy - Thursday, May 29, 2014 - link

    Ian, in the "dGPU Benchmarks with ASUS HD7970" portion of your review, it would have been interesting to see some Mantle results on these low power CPUs.
  • JBVertexx - Thursday, May 29, 2014 - link

    I think the value in having a socket solution is less about providing an upgrade path and more about lower carrying costs in the entire supply chain.

    If you look at having 4 CPU combinations over lets say 4 motherboard options, having a BGA solution means that you need to source and stock 16 different items. With a socket solution, that cuts your inventory and carrying cost down to 8 items.

    The economics of this are huge. It impacts motherboard manufacturers, system builders, and businesses. It impacts the amount of up front investment required by every organization in the supply chain, and it impacts the inventory costs (or carrying capital).

    It especially impacts motherboard manufacturers, who must actually purchase the CPU in a BGA solution in order to sell a motherboard.

    In the face of those compelling economics, having an upgrade path is really small potatoes.
  • marvee - Thursday, May 29, 2014 - link

    The understanding of those economics could be the experience of Rory Read, from his time with Lenovo.
  • Hrel - Thursday, May 29, 2014 - link

    Pretty disappointing you guy didn't include a CPU with HD4600 on it in the gaming benchmarks. Why compare to last generation's hardware? Perhaps to show AMD in as favorable a light as possible? hmmmmm.....

Log in

Don't have an account? Sign up now