chipsaetze

Chipsets

In short: One or more chips on the motherboard that control the data connections between the CPU, memory, expansion cards and peripherals.

In more detail: The chipset determines, among other things, how many PCIe lanes, USB ports and RAM channels are usable, as well as which CPU generations are supported. With modern CPUs, some functions that used to sit in the chipset (e.g. the memory controller) have moved directly into the CPU.

In Depth

From two chips to one

Historically, a chipset consisted of two separate chips: the “northbridge” (fast connections to the CPU, RAM and graphics card, placed close to the CPU, since this is where the most time-critical connections ran) and the “southbridge” (slower peripherals like USB, SATA, network, which could be placed further from the CPU). Over time, more and more northbridge functions — above all the memory controller and the PCIe connection to the graphics card — moved directly into the CPU itself, because shorter physical paths mean lower latency and less energy loss. Usually only a single chip remained (still often called the “chipset” or Platform Controller Hub, PCH), connecting the remaining, less time-critical peripherals.

Why the chipset limits the feature set

When deciding what to buy, the chipset is often more important than it initially seems: it determines how many additional NVMe drives, USB ports of which generation, and how many expansion card lanes a motherboard can offer at all, regardless of what the CPU could theoretically achieve — two motherboards with the same CPU support can differ massively in features and price, purely because of different chipsets.

Model hierarchies

Chip manufacturers typically offer a tiered chipset hierarchy (e.g. Intel’s “Z”, “B” and “H” series, AMD’s “X” and “B” series): high-end chipsets usually also allow overclocking of the CPU and/or RAM and offer more PCIe lanes as well as more USB ports, while cheaper entry-level chipsets deliberately lock these features in software, even though the underlying chip hardware can be technically identical or very similar in some cases — a pure market-segmentation decision by manufacturers to serve different price brackets.

Chipset drivers

Under the operating system, the chipset needs its own drivers so that all connected components (especially USB controllers, SATA controllers) work correctly and at full speed — missing or outdated chipset drivers are a common, often-overlooked cause of seemingly inexplicable performance or stability problems on newly set-up systems.

Socket compatibility as a purchasing criterion

The chipset is closely tied to the CPU socket generation: a new chipset usually appears together with a new CPU generation and initially often only supports that one, while older chipsets are sometimes (but not guaranteed to be) unlocked for newer CPU generations via BIOS updates. When buying a new motherboard, it’s therefore always worth checking the manufacturer’s “compatibility list” (QVL, Qualified Vendor List) to make sure the desired CPU generation is actually supported — especially for very recently released processors, for which some older motherboard batches still need a BIOS update before the first boot.

Integrated vs. discrete functions

A trend of recent years is that functions which used to necessarily sit in the chipset are increasingly moving directly into the CPU — besides the memory controller, this now often also includes part of the PCIe lanes for the fastest NVMe SSD or the graphics card. The remaining chipset today therefore mainly handles “additional”, less time-critical connections — extra USB and SATA ports, further PCIe lanes for expansion cards, and often integrated Wi-Fi/Bluetooth on more compact systems.

See also: Motherboard/Mainboard, CPU, PCIe, USB