We first picked up AMD's Fusion series last February when we tested the 18W dual-core Zacate APU, formerly known as the E-350. The Zacate APUs were developed for netbook-like applications and effortlessly pushed existing Intel solutions aside. They offer an affordable yet powerful solution for the atom / ion combination that was common at the time.
Shortly after the release of Zacate, we had the opportunity to test AMD's A8-3850 desktop APU, code-named Llano, which contained "Husky" CPU cores, which were essentially the Phenom II mobile architecture, and integrated graphics the Redwood class (WinterPark for the dual-core versions and BeaverCreek for the quad-core versions).
Like Zacate, we felt that Llano would be a success for AMD, and for the most part it was a hit with certain users. Even today, top-notch Intel chips like the Core i7-3770K can't exceed the graphics performance of the A8-3850, while many Ivy Bridge-based Core i5 and i7 parts have an even slower HD 2500 graphics engine.
Granted, Intel still dominates the processor market and its products are generally the way to go if you want the fastest possible CPU. However, AMD's APUs offer an attractive alternative for people who don't need Ivy Bridge or discrete GPU performance, but still want more graphics performance than Intel's IGPs.
AMD has further refined its fusion offerings and launched its Trinity series on mobile platforms four months ago – probably where its APUs offer the greatest value. These 32 nm parts have four CPU cores based on Piledriver, Bulldozer's successor, and a GPU based on Cayman of the Northern Islands (HD 6000) series from 2010.
This week, AMD is finally ready to offer a desktop version of Trinity that includes a new socket and a new high-end chipset. Given that Piledriver has improved bulldozer power consumption, we expect Trinity to be more efficient than Llano, while Cayman's VLIW4 architecture should increase the speed of the GPU – at least we hope.
32nm Trinity line-up
Piledriver cores are distributed across three different 32 nm APU series: Trinity, Weatherford and Richland. We will only deal with Trinity, which covers the performance segment and replaces the Llano-based A8 series. Weatherford covers the upper mainstream market and replaces the A6 series based in Llano, while Richland covers the lower mainstream area and replaces the A4 series based in Llano.
There are six new Piledriver-based APUs, four of which are from the Trinity range, and we're going to test the A10-5800K, a quad-core part that runs at 3.8 GHz and a maximum turbo frequency of 4.2 GHz works and has a 4 MB L2 cache. The GPU is known as the Radeon HD 7660D, which has 384 cores and operates at 800 MHz. Like the processors of the "K" series from Intel, the A10-5800K has been unlocked for easier overclocking.
A-series core design
As already mentioned, the Trinity Piledriver cores are based on the same bulldozer architecture as the current FX series. However, AMD changed the design slightly. For example, the L3 cache was left. The new A10 and A8 APUs correspond to the FX-4000 series with 4 MB L2 cache, while the A6 and A4 parts only have 1 MB.
Although the L3 cache increases performance in certain situations, it also increases power consumption and essentially affects the efficiency of these chips. While the smaller dedicated L2 cache can be enabled or disabled when the cores are needed, the entire L3 cache stays awake even when only one core is used. Apparently AMD believed that the performance compromise was not worth it.
Despite clearing the L3 cache, Trinity's transistor count is still higher than that of the Phenom II X6 1100T and AMD FX-8170. In fact, Trinity's transistor count is only slightly lower than that of the Intel Core i7 Ivy Bridge (22 nm) processors.
The chip area of the quad-core APUs is 246 mm², which is larger than the 160 mm² chip area of the high-end processors Ivy Bridge Core i5 and Core i7. Obviously, making larger matrices costs more, and since the Trinity APUs are significantly larger than their competition, we have no doubt that this will affect AMD's bottom line.
Still, Trinity and his talent are incredible when you look at processors and platforms from a few years ago. AMD has a 66 mm² (13 W) Northbridge, a 200 mm² (65-95 W) quad-core processor and a 108 mm² (30 W) graphics processing unit – which were once three completely separate components – to a 246 mm² ( 65-100 W). A-series APU.