Glossary

The circuit that converts 12 V from the power supply into the ~1.25 V a CPU core runs on.

A voltage regulator module is a bank of switching converters between the 12 V rails of your power supply and the CPU socket. It steps 12 V down to roughly 1.1–1.3 V while delivering a couple of hundred amps, and it does that with an efficiency of around 90 %, which means the missing 10 % leaves as heat through the MOSFETs. That heat is the whole subject of this site: when a VRM gets hot enough, the board protects itself by limiting how much current it will pass, and the CPU quietly loses clock speed.

One switching element of the VRM: a high-side FET, a low-side FET and a driver in one package.

A power stage — marketed as DrMOS or SPS — packages the high-side MOSFET, the low-side MOSFET and the gate driver into a single component with a published continuous current rating, usually between 45 A and 110 A. Counting stages and multiplying by that rating is how you get a board's theoretical core current capacity. Cheaper boards use discrete MOSFET pairs instead, which have separate high- and low-side ratings and worse thermal behaviour for the same nominal amps.

One controller channel of the VRM. More phases spread the same current over more silicon.

Each phase of a VRM switches in turn, so an eight-phase design has each stage carrying an eighth of the total core current at any moment. Spreading current is the point: two stages sharing 100 A run far cooler than one stage carrying it. Vendor specifications often quote a total like "16+1+2", where only the first number feeds the CPU cores — the others feed the SoC or integrated graphics and carry none of the core load.

Driving two power stages from one controller channel through a doubler chip.

A PWM controller with eight channels can drive sixteen power stages if each channel passes through a doubler. The result carries almost as much current as sixteen true phases and costs much less, at the price of slightly slower transient response. A teamed design is the cheaper variant again: two stages wired to one channel with no doubler, so they switch together rather than alternately. Our model derates doubled designs to 90 % and teamed designs to 85 % of their nominal rating.

Intel's sustained and short-term power limits. PL1 is the long-run ceiling, PL2 the boost ceiling.

Intel processors run to PL2 for a window called tau and then settle back to PL1. On a locked board that window is honoured, so a 65 W non-K part really does average 65 W. On most enthusiast boards tau is set to effectively unlimited, which means a K-series part holds PL2 — its Maximum Turbo Power — indefinitely. That is why the sustained draw of a Core i7-14700K in this database is 245 W rather than its 125 W base figure.

AMD's package power ceiling: the most power the socket will deliver to the CPU.

Package Power Tracking is the AMD equivalent of a power limit, set to roughly 1.35 times the rated TDP. A 65 W Ryzen has an 88 W PPT and genuinely draws close to it under load; a 170 W Ryzen 9 has a 230 W PPT. AMD's X3D parts are the interesting case, because their PPT is high but their measured draw is far lower — a 7800X3D rarely passes 105 W however hard you load it.

How long an Intel CPU is allowed to hold PL2 before dropping to PL1.

Tau is a time constant, typically 28 seconds on a locked configuration. Boards aimed at enthusiasts routinely ship with tau raised to hundreds of seconds or removed entirely, which turns a short boost into a permanent state and moves the whole load onto the VRM. Two boards with the same power stages can therefore behave differently out of the box purely because of their default tau.

Sustained CPU power divided by the board's usable VRM capacity. The number this site is built on.

The stress ratio is the single figure that predicts throttling: how much of the board's sustained core-power capacity a given processor actually asks for. Below 0.65 nothing interesting happens. Between 0.65 and 0.85 the VRM runs warm and clocks slip a little. Above 0.85 the board is the limiting component and you lose real performance. Capacity here is already derated for phase design and heatsink mass, so it is lower than a vendor's headline current rating.

A button that updates firmware from a USB stick with no CPU installed.

USB BIOS Flashback on ASUS boards, Q-Flash Plus on Gigabyte and Flash BIOS Button on MSI all do the same thing: they let the board read a firmware image from a USB stick using only the power supply, without a working processor in the socket. It matters when you buy a board that predates your CPU — without it, a board on old firmware will not post with the new chip, and you need to borrow an older processor or find a shop that will flash it.

One-click memory overclocking profiles: EXPO on AMD, XMP on Intel.

DDR5 sticks boot at a JEDEC speed — usually 4800 MT/s — and reach their advertised speed only when you enable a stored profile in the BIOS. XMP is Intel's format, EXPO is AMD's, and many kits carry both. A kit with only XMP usually works on an AMD board, but the sub-timings are tuned for Intel's controller, so an EXPO kit is the safer buy for a Ryzen build.

Splitting the CPU's sixteen graphics lanes so another device can use some of them.

A desktop CPU provides a fixed number of PCIe lanes — twenty on Alder Lake through Raptor Lake, twenty-four on AM5 and Arrow Lake. When a board offers a second CPU-attached M.2 slot, those four lanes have to come from somewhere, and that somewhere is the sixteen belonging to the graphics slot. Populating the shared slot therefore drops the graphics card to x8. In practice a current card loses one or two percent, which is nothing next to the drive's speed, but it is worth knowing before you wonder why your GPU reports x8.

The secondary controller that provides the ports the CPU has no lanes for.

The chipset — B650, Z790, B860 and friends — hangs off four lanes from the CPU and fans them out into SATA ports, USB controllers, extra M.2 slots and network interfaces. It also decides policy: whether the board can overclock the CPU, how much memory tuning is allowed, and how many USB ports of each speed exist. It has nothing to do with VRM quality, which is why a cheap Z790 board can throttle a processor that a good B760 board handles comfortably.

A component reducing its own speed to stay within a temperature limit.

Throttling is a protection mechanism, not a fault. When a VRM's temperature sensor passes the board's limit the firmware reduces the current it will pass, and the CPU responds by dropping multiplier steps until the power draw fits. From the outside it looks like a benchmark that starts fast and finishes slow, and it is easy to blame the cooler, the memory or the game. The tell is that the CPU package temperature is fine while performance falls anyway.

The physical CPU interface. AM5 and LGA1851 are the current ones.

A socket defines pin count, pin layout and the electrical contract between processor and board, and it is absolute: an AM5 processor does not fit an AM4 board no matter how new either part is. AMD keeps sockets alive for years — AM4 ran from 2016 to 2024 — while Intel has historically changed socket every two generations, which is why an LGA1700 board and an LGA1851 board look almost identical and accept completely different chips.

The voltage rail that feeds the CPU cores, and the only rail this model counts.

Vcore is the main core supply, typically between 1.0 V and 1.35 V under load. It is the rail that carries hundreds of amps and the rail whose regulator gets hot. Boards also regulate SoC, VDDIO, memory and integrated-graphics rails, and vendors often add those phases to the headline number. Our capacity figures use Vcore stages only, because a board with six core phases and four auxiliary phases is a six-phase board as far as your processor is concerned.