Where once the interface for desktop CPUs was divided by age and price, AMD breaks out low-power platforms as a third class from which to choose. We’ll organize these by popularity.
Intel LGA 1150
Supporting Intel’s widest range of microprocessors, LGA 1150-based motherboards connect two channels of DDR3 memory and a maximum of 16 full-speed (8 GT/s) PCI Express 3.0 lanes, which can be split among up to three add-in devices. The CPU itself holds both the memory and PCIe 3.0 controllers, removing the need for a separate northbridge on the motherboard’s chipset. Instead, a single-component platform controller hub (or PCH) fills the role of a traditional southbridge. That piece of silicon hosts a secondary PCIe 2.0 controller to connect lower-bandwidth devices.
Because it has so few PCIe connections, LGA 1150 is generally best-suited to folks who require only a few expansion cards. The bandwidth benefit of PCIe 3.0 allows spectacular performance from multi-GPU rendering technologies like SLI and CrossFire, but adding a third card to the array can be problematic (Nvidia goes so far as to block SLI compatibility on four-lane slots). Moreover, all eight of the PCIe 2.0 pathways share a 2 GB/s CPU link with all of the chipset’s integrated devices, including all six of the PCH’s SATA 6Gb/s ports, all six of its USB 3.0 ports, and any GbE networking controllers.
AMD Socket AM3+
AMD’s three-year-old Socket AM3+ continues as its flagship solution, even as the company backs away from the high-end market and continues to improve its mainstream replacement parts. The top reasons for this being a top platform include the associated 990FX chipset, which provides 42 PCI Express 2.0 lanes through its northbridge and a couple more on its southbridge. The CPU-integrated memory controller supports dual-channel memory up to DDR3-1866 (plus a little more with overclocking). And speaking of overclocking, the CPU range extends from a 4.7 GHz liquid-cooled eight-core model pushed well beyond the original engineering specs of its architecture core, down to a $110 four-core model.
Due to the platform’s end-of-life status, we recommend it only to buyers who’ve weighed their other options carefully enough to make a fully informed commitment.
Intel LGA 2011-v3
Supporting Intel’s Haswell-E (5900 and 5800-series) Core i7 processors with up to eight physical cores, LGA 2011-v3 directs up to 40 PCIe 3.0 lanes directly from the CPU to expansion slots. The large CPU-based PCIe controller, in addition to four DDR4 memory channels, make it the best choice for users who need both top compute performance and added support for high-bandwidth expansion cards.
Unlike its earlier high-end socket, Intel also differentiates its top 5900-series models by disabling twelve of the integrated PCIe 3.0 pathways on its second-class 5800-series processors. That step removes 4-way SLI from the 5800-series CPU's capabilities, in an apparent effort to drive-away customers who might have otherwise paired a mid-priced CPU with an expensive graphics configuration. Depending on the motherboard chosen, the reduced lane count of 5800-series CPUs can also disable 3-way SLI.
An 8-lane PCIe 2.0 controller resides in the chipset and carries data over the same 2 GB/s DMI pathway as LGA 1150.
Intel LGA 2011
Supporting Intel’s Ivy Bridge-E (4900 and 4800-series) and Sandy Bridge-E (3900 and 3800-series) Core i7 processors with up to six physical cores, LGA 2011 directs 40 PCIe lanes directly from the CPU to several slots. Because this 40-lane controller was on the CPU, the newer Ivy Bridge processor was able to add PCIe 3.0 mode to a platform that had originally been PCIe 2.0-only.
Current LGA 2011 platforms should be considered “end of life” since Intel has released its "v3" replacement. Value-seeking buyers might select this product based on the 4800-series CPU's 40-lane controller, which is reduced to 28-lanes on the replacement-platform's 5800-series processor. Similarly, DDR3 is more widely-available and at a lower current price compared to DDR4. Buyers should keep the end-of-life status in mind when considering potential upgrades.
AMD Socket FM2+
AMD’s version of a mainstream platform resembles Intel’s, with sixteen PCIe 3.0 lanes feeding one or two high-bandwidth (typically graphics) expansion cards. Compared to Intel, AMD reduces the impact of a 2 GB/s chipset link by putting four of the platform’s eight PCIe 2.0 lanes on the CPU.
Unlike Intel’s solution, Nvidia doesn’t support SLI on AMD’s FM2+ chipset. It’s still CrossFire-compatible, and even supports a hybrid mode to purportedly boost the performance of a low-cost AMD graphics card by pairing it with integrated graphics. We've measured issues with this technology though, and aren't recommending it to our readers.
AMD Socket AM1
AMD’s Socket AM1 interface integrates the entire chipset onto the CPU to save both energy and cost. These low-performance processors support a single graphics card at PCIe 2.0 x4, four additional PCIe-based devices (on-board or by expansion slot), two USB 3.0 ports, and a pair of SATA 6Gb/s drives. It primarily competes with CPU-integrated motherboards, but the addition of a socket gives AMD a little more room to market additional CPU models.