The AMD Kabini Review: A4-5000 APU Tested
by Jarred Walton on May 23, 2013 12:00 AM ESTKabini vs. Clover Trail & ARM
Kabini is a difficult SoC to evaluate, primarily because of the nature of the test system we're using to evaluate it today. Although AMD's Jaguar cores are power efficient enough to end up in tablets, the 15W A4-5000 we're looking at today is a bit too much for something the size of an iPad. Temash, Kabini's even lower power counterpart, will change that but we don't have Temash with us today. Rather than wait for AMD to get us a Temash based tablet, I wanted to get an idea of how Jaguar stacks up to some of the modern low-power x86 and ARM competitors.
To start, let's characterize Jaguar in terms of its performance compared to Bobcat as well as Intel's current 32nm in-order Saltwell Atom core. As a reference, I've thrown in a 17W dual-core Ivy Bridge. The benchmarks we're looking at are PCMark 7 (only run on those systems with SSDs), Cinebench (FP workload) and 7-Zip (integer workload). With the exception of Kabini, all of these parts are dual-core. The Atom and Core i5 systems are dual-core but have Hyper-Threading enabled so they present themselves to the OS as 4-thread machines.
| CPU Performance | ||||||||||||||||
| PCMark 7 | Cinebench 11.5 (Single Threaded) | Cinebench 11.5 (Multithreaded) | 7-Zip Benchmark (Single Threaded) | 7-Zip Benchmark (Multithreaded) | ||||||||||||
| AMD A4-5000 (1.5GHz Jaguar x 4) | 2425 | 0.39 | 1.5 | 1323 | 4509 | |||||||||||
| AMD E-350 (1.6GHz Bobcat x 2) | 1986 | 0.32 | 0.61 | 1281 | 2522 | |||||||||||
| Intel Atom Z2760 (1.8GHz Saltwell x 2) | - | 0.17 | 0.52 | 754 | 2304 | |||||||||||
| Intel Core i5-3317U (1.7GHz IVB x 2) | 4318 | 1.07 | 2.39 | 2816 | 6598 | |||||||||||
Compared to a similarly clocked dual-core Bobcat part, Kabini shows a healthy improvement in PCMark 7 performance. Despite the clock speed disadvantage, the A4-5000 manages 22% better performance than AMD's E-350. The impressive gains continue as we look at single-threaded Cinebench performance. Again, a 22% increase compared to Bobcat. Multithreaded Cinebench performance scales by more than 2x thanks to the core count doubling and increased multi-core efficiency. The current generation Atom comparison here is just laughable—Jaguar offers more than twice the performance of Clover Trail in single threaded Cinebench.
The single threaded 7-Zip benchmark shows only mild gains if we don't take into account clock speed differences. If you normalize for CPU frequency, Jaguar is likely around 9% faster than Bobcat here. Multithreaded gains are quite good as well. Once again, Atom is no where near AMD's new A4.
The Ivy Bridge comparison is really just for reference. In all of the lightly threaded cases, a 1.7GHz Ivy Bridge delivers over 2x the performance of the A4-5000. The gap narrows for heavily threaded workloads but obviously any bigger core going into a more expensive system will yield appreciably better results.
For the next test I expanded our comparison to include an ARM based SoC: the dual-core Cortex A15 powered Samsung Exynos 5250 courtesy of Google's Nexus 10. These cross platform benchmarks are all browser based and run in Google Chrome:
Here we see a 14% improvement over Bobcat, likely closer to 20% if we normalized clock speed between the parts—tracking perfectly with AMD's promised IPC gains for Jaguar. The A4-5000 completes the Kraken benchmark in less than half the time. The 1.7GHz Ivy Bridge part is obviously quicker, but what's interesting is that if we limit the IVB CPU's frequency to 800MHz Kabini is actually a near identical performer.
Jaguar seems to be around 9-20% faster than Bobcat depending on the benchmark. Multithreaded workloads are obviously much better as there are simply more cores to run on. In practice, using the Kabini test system vs. an old Brazos machine delivers a noticeable difference in user experience. Clover Trail feels anemic by comparison and even Brazos feels quite dated. Seeing as how Bobcat was already quicker than ARM's Cortex A15, its no surprise that Jaguar is as well. The bigger problem here is Kabini needs much lower platform power to really threaten the Cortex A15 in tablets—we'll see how Temash fares as soon as we can get our hands on a tablet.
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whyso - Thursday, May 23, 2013 - link
kabini only has a single channel memory controller. Going to two DIMMS would not improve performance at all.Gaugamela - Thursday, May 23, 2013 - link
He didn't mention dual channel memory not even once in his comment. He mentioned comparing a inexpensive chip that competes against Atoms/Pentiums in price/performance/TDP with an intel i5 which is a much more powerful chip.Roland00Address - Thursday, May 23, 2013 - link
I wonder how starvered the cores are for memory bandwith. Even the xbox one will be using quad channel memory (4 64 bit controllers) and 2133 mhz instead of 1600, that is over five times the bandwidth. The ps4 keeps the quad channel but uses gddr5 memorywhyso - Thursday, May 23, 2013 - link
Well the xbox one has 6x the igp and the ps4 has 9x the igp.Roland00Address - Thursday, May 23, 2013 - link
I am not asking if the gpu is bandwidth starved but is the cpu bandwidth starvedI understand why amd went single channel, I am just curious if dual channel would make a difference
whyso - Thursday, May 23, 2013 - link
CPU is almost never bandwidth starved. Literally, you can run a 3770k on 1033 mhz ram and outside winrar you will never notice any differences compared to 2133 mhz ram. 3770k is dual channel but more than 4x as powerful as this kabini apu.Roland00Address - Thursday, May 23, 2013 - link
Your statement that an i7 does not need faster memory does not necessarily translate to this situation with jaguar and that is why I am curious if the cores are starved. I wish it was possible for anandtech to test this (but it is very hard to do so for there isn't really laptop ram faster than 1600 mhz for laptops). Here is why you can't just assume what works with an i7 translates with the jaguar chip.533 mhz dual channel is equivalent to 1066 single channel. (Remember i7-3770k is dual channel while amd jaguar in this implementation is single channel). Thus you can't just assume an i7 is fine with dual channel, than the jaguar would be fine with single channel for the i7 has 100% more bandwidth due to it being dual channel.
Furthermore i7-3770k is intels high performance architecture with large r&d vs amd's energy efficent architecture with small r&d chip. It is very likely intel has better data predictors in their i7 so there's less cache miss and thus you don't care about the memory speed. Intel R&D money is a big deal and translates into better IPC for many reasons including branch prediction.
Lets put it this way arm is going higher bandwidth for more ipc. Tegra 3 is a mere single channel 32 bit controller, Tegra 4 is likely to be a dual channel 32 bit controller, Exynos 5 uses a dual channel 32 bit controller. Apple on their Ipads now use a quad channel 32 bit controller. One reason why exynos and ipad were faster than tegra 3 was better memory bandwidth.
I am not saying you will see improvements greater than 20% but I am curious if faster memory speeds would cause ipc to go up from 5 to 20%. For example with bulldozer amd gets 8% faster encoding with x264 first pass with 2133 memory dual channel instead of 1333 dual channel according to vr-zone.
It may not be in amd best interest to make the jaguar chip dual channel 64 bit for cheap laptops that compete against intel's celeron or pentium lines, for laptops. Yet at the same time Jaguar is going to be AMD process for low power in the future. It is quite possible that AMD may in the future (if the tdp is low enough) make a 20nm dual channel chip for the higher margin tablets, high margin tablets would insist on higher ipc for the cpu and more bandwidith for the screen, while low margin cheap computers would not care about increase ipc. It is possible that in the future AMD can find a sweet spot between intel atom and intel haswell. (I am not saying this is likely, just merely possible all depends on intel's pricing to oems for haswell.)
whyso - Thursday, May 23, 2013 - link
It is extremely unlikely for this chip's cpu to be hurt by memory bandwidth. Sure the i7 has 100% more bandwidth but you must factor in the power of the chip. The i7-3770k is going to be something like 6x more powerful (3.7 ghz turbo + IPC advantage + HT). Even if the kabini chip tested in this review was half as efficient as the 3770k in utilizing memory bandwidth it still wouldn't show any differences in cpu performance.Phone/tablet SOCs mainly need the bandwidth for the gpu portion of the die (the high res screen was the reason that apple needed such an interface). If they need more bandwidth it'll be for the igp portion of the die (definitely 1066 mhz ram on a single channel will hurt this thing) for kabini.
geoflouw - Thursday, May 23, 2013 - link
Need a comparison against Haswell and Baytrail please. This data is misleading, i really would hope AMD can compete with 1 year old CPUs and SOCs.....smilingcrow - Thursday, May 23, 2013 - link
It’s hardly misleading. Haswell is still under NDA and Bay Trail is due around Q4 which is why they aren’t compared. The better comparison will be Bail Trail based on pricing and performance. AMD should still have a healthy lead for GPU but if Intel’s recent info is true it should be close on the CPU front. The main difference is that Bay Trail has a low enough TDP for a cheap fanless tablet whereas the chip reviewed today is 15W so Ultrabook class. So you get two out of four with AMD:The Good: GPU + Price
The Bad: power consumption + low IPC
So business as usual really.