The AMD Trinity Review (A10-4600M): A New Hope

Mobile Trinity Lineup

Trinity is of course coming in two flavors, just like Llano before it. On the desktop, we’ll have Virgo chips, but those are coming later this year (around Q3); right now, Trinity is only on laptops. On laptops the codename for Trinity is Comal. AMD has also dropped wattages on their mobile flavors, so where Llano saw 35W and 45W mobile parts, with Comal AMD will have 17W, 25W, and 35W parts. (The desktop Trinity chips will apparently retain their 65W and 100W targets.) There aren’t a ton of mobile Trinity chips launching today; instead, AMD has five different APUs and each one targets a distinct market segment. Here’s the quick rundown:

As a Bulldozer-derived architecture, Trinity uses CPU modules that each contain two Piledriver CPU cores with a shared FP/SSE (Floating Point) unit. From one perspective, that makes Trinity a quad-core or dual-core processor; others would argue that it’s not quite the same as a “true” quad-core setup. We’re not going to worry too much about the distinction here, though, as we’ll let the performance results tell that story. Compared to Llano’s K10-derived CPU core, clock speeds in Trinity are substantially higher—both the base and Turbo Core clocks. The top-end A10-4600M has a base clock that’s 53% higher than the 1.5GHz A8-3500M we reviewed when Llano launched, while maximum turbo speeds are up 33%. Unfortunately, while clock speeds might be substantially higher, Trinity’s Piledriver cores have substantially longer pipelines than Llano’s K10+ cores; we’ll see in the benchmarks what that means for typical performance.

The GPU side of the equation is are also substantially different from Llano. Llano used a Redwood GPU core (e.g. Radeon 5600 series) with a VLIW5 architecture (e.g. the Evergreen family of GPUs), and the various APUs had either 400, 320, or 240 Radeon cores. Trinity changes out the GPU core for a VLIW4 design (Northern Islands family of GPU cores), and this is the only time we’ve seen AMD use VLIW4 outside of the 6900 series desktop GPUs. The maximum number of Radeon cores is now 384, but we should see better efficiency out of the design, and clock speeds are substantially higher than on Llano—the mobile clocks are typically 55-60% higher. Again, how this plays out in terms of actual performance is something we’ll look at momentarily.

Looking at the complete lineup of Trinity APUs, it’s interesting to see AMD using a new A10 branding for the top models while overlapping the existing A8 and A6 brands on lower spec models. We only have the A10-4600M in for testing right now, but AMD provided some performance estimates for the various performance levels. The A10-4600M delivers 56% better graphics performance and 29% better “productivity” performance than the A8-3500M—note that we put productivity in quotes because it’s not clear if AMD is talking specifically about CPU performance or some other metric. The new A8-4500M delivers 32% faster graphics performance than the A8-3500M and 19% higher productivity, which appears to be why it gets the same “A8” classification. Finally, even the single-module/dual-core A6-4400M delivers 16% better graphics than the A8-3500M and 5% higher productivity. I suspect that the various percentages AMD lists are more of an “up to” statement as opposed to being typical performance improvements, as it seems unlikely that 192 VLIW4 cores at 686MHz could consistently outperform 400 VLIW5 cores at 444MHz.

If we consider target markets, the A10-4600M will be the fastest Trinity APU for now, and it should go into mainstream laptops that will provide a well rounded experience with the ability for moderate gaming along with any other tasks you might want to run. The A8-4500M takes a pretty major chunk out of the GPU (one third of the GPU cores are gone along with a slight drop in maximum clock speed) while maintaining roughly 80% of the CPU performance, so it can fit into slightly cheaper laptops but will likely drop gaming performance from “moderate” to “light”. The A6-4400M ends up as the extreme budget offering, with higher clocks on the CPU making up for the removal of two cores; the GPU likewise gets a slight trim relative to the A8-4500M, and we’re now down to half the graphics performance potential of the A10-4600M. All of the standard voltage parts support up to DDR3-1600 memory, with low voltage DDR3-1600 and ultra low voltage DDR3-1333 also supported.

The other two APUs are low voltage and ultra low voltage parts, which should work well in laptops like HP’s “sleekbooks”—basically, they’re for AMD-based alternatives to ultrabooks. The A10-4655M has about 87% of the CPU performance potential of the A10-4600M, with 70% of the GPU performance potential, and it can fit into a 25W TDP. The A6-4455M drops the TDP to 17W, matching Intel’s ULV parts, but again the CPU and GPU cores get cut. This time we get two Piledriver cores, 256 Radeon cores, and lowered base and maximum clock speeds. The low/ultra low voltage parts also drop support for DDR3-1600 memory, moving all RAM options down one step to DDR3-1333, low voltage DDR3-1333 and ultra low voltage DDR3-1066.

The final piece of the puzzle for any platform is the chipset. AMD is using their A70M (Hudson M3) chipset, which is the same chipset used for Llano. That’s not really a problem, though, as the chipset provides everything Trinity needs: it has support for up to six native SATA 6Gbps ports, four USB 3.0 ports (and 10 USB 2.0 ports), RAID 0/1 support, and basically everything else you need for a mainstream laptop. PCI Express support in Trinity remains at PCIe 2.0, but that’s not really a problem considering the target market. PCIe 3.0 has been shown to improve performance in some GPGPU workloads with HD 7970, but that’s a GPU that provides nearly an order of magnitude more compute power (over 7X more based on clock speeds and shader count alone).

That takes care of the overview of AMD’s Mobile Trinity lineup, and Anand has covered the architectural information, so now it’s time to meet our prototype AMD Trinity laptop.