VRM phases for Ryzen CPUs: how many are enough?

As experience shows, VRM manufacturers cannot do without multi-phase designs. Increasing the number of phases increases total current and power delivery and helps stabilize voltage. The purpose of power phases is to convert the input voltage into exactly the level required for the processor to operate.

This article explains how many power phases are required for the Ryzen 5600X, 5800X3D, and 5900X processors. In most cases, the number of phases specified by manufacturers is mostly marketing. Phases are labeled A + B, where A refers to the CPU core power phases and B to integrated graphics and memory. The “×2” symbol indicates the use of doublers…

General understanding of Power Phases

The VRM power delivery system is a system of components on the motherboard. It converts the high voltage from the power supply unit (usually 12 V) into a lower voltage required by the processor (around 1–1.5 V). The CPU also requires a high current draw, which can reach tens of amperes.

It includes the PWM controller itself, MOSFETs, inductors, and capacitors. The PWM controller determines how much power needs to be delivered to the CPU. The other components perform regulation and signal filtering functions. The wider the pulses are, the higher the current supplied…

Each power phase delivers power to the processor. It is a circuit made up of capacitors, inductors, and transistors that must operate in synchrony. The more true power phases there are, the more stable and cleaner the output voltage will be.

How much power do Ryzen CPUs consume?

The thermal design power (TDP) of the Ryzen 9 5950X is rated at 105 W, but its power limit is set to 142W. In practice, when boosting up to 4.6 GHz, power consumption rises to 231 W. Under a heavy Cinebench R23 load, the current draw reaches 163 A at a voltage of 1.42 V.

All processors have already been extensively tested. You can find power consumption data for any of them. This value may vary depending on load, frequency, and voltage settings. It is important to note that overclocking and stress testing are indeed extreme operating conditions…

VRM real-world performance and limits

For example, the GIGABYTE X570S AORUS MASTER motherboard features an updated VRM design. It has a 14+2 phase power delivery design, and the XDPE132G5C PWM controller can control all 16 phases. It is equipped with Infineon TDA21472 MOSFETs, rated at up to 70 A.

In the technical specifications of this MOSFET, we need to examine the operating characteristics. We are interested in the current vs. temperature graph (Fig. 5). The rated 70 A can only be achieved at sub-zero temperatures. At 60 °C, it provides approximately 50 A, which gives 14 phases × 50 A = 700 A.

The efficiency graph (Fig. 4) shows that at a current of 50 — 55 A, efficiency is about 92%. Theoretically, this configuration corresponds to 700 A × 92% = 644 A to the CPU. In practice, temperatures are higher, meaning the maximum possible load is even lower. These are real phases without doublers…

How many power Phases are required for Ryzen 5000?

For 12- and 16-core CPUs (200+ W), 6 phases (minimum 40 A) with doublers are required. 8-core CPUs (up to 150 W) require 5 phases (minimum 50 A) with a doubler or DualOut configuration. 6-core CPUs (75 W) require at least 4 actual phases. Please refer to the table, as 6 power phases using 50 A and 90 A MOSFETs are not the same thing.

We won’t focus on current draw. CPU power consumption alone is more than enough for our purposes. The full version of the TABLE includes more data. CPU power consumption: 200 W: 3950X OC, 5900X OC, 5950X OC; 175 W: 5800X OC, 3950X, 5900X, 5950X; 150 W: 2700X OC, 3800X OC, 5800X, 3900X; 125 W: 3600X OC, 2700X, 3800XT, 5800X3D; 100 W: 5600X, 3700X, 3800X и 5700X.	+	Will work without any issues. Fully compatible.
	*	Airflow is essential, though it will run fine under light loads.
	**	Strong airflow is recommended, otherwise high VRM temperatures may occur.
	–	Not recommended. Compatible only on paper. Expect overheating and throttling.

Table 1. X570 and X570S motherboard VRM ratings

It indicates how many phases are required for Ryzen CPUs, taking VRM capabilities into account. In practice, a 6-phase power delivery system is more than enough. Such setups typically feature high-quality VRM cooling. A 6 × 2 configuration (50A with doublers) allows the Ryzen 9 5950X to be overclocked comfortably.

Model	200	175	150	125	Phases		Mosfet (SPS)
ASRock X570 AQUA	+	+	+	+	6×2	Doubler	1x IR3555 60A
ASRock X570 Creator	+	+	+	+	6×2	Doubler	1x IR3555 60A
ASRock X570 Taichi Razer Edition	+	+	+	+	7×2	Doubler	1x SiC634 50A
ASRock X570 Taichi	+	+	+	+	6×2	Doubler	1x SiC634 50A
ASRock X570 Extreme4 WiFi ax	**	*	+	+	4×2	Doubler	1x SiC632A 50A
ASRock X570 Pro4	–	**	*	+	4×2	Doubler	SM4336/4337[1×1]
ASRock X570M Pro4	–	**	*	+	4×2	Doubler	SM4336/4337[1×1]
ASRock X570 Steel Legend WiFi ax	**	*	+	+	4×2	Doubler	1x SiC632A 50A
ASRock X570 PG Velocita	+	+	+	+	6×2	Doubler	1x SiC634 50A
ASRock X570S PG Riptide	*	*	+	+	4	DualOut	2x SiC654 50A
ASRock X570 Phantom Gaming X	+	+	+	+	6×2	Doubler	1x SiC634 50A
ASRock X570 Phantom Gaming 4 WiFi ax	–	**	*	+	4×2	Doubler	SM4336/4337[1×1]
ASRock X570 Phantom Gaming 4S	–	–	**	*	3×2	Doubler	SM4336/4337[2×2]
ASRock X570 Phantom Gaming-ITX/TB3	–	**	*	+	4×2	Doubler	1x ISL99227 60A
ASUS ROG Crosshair VIII Formula	+	+	+	+	7	DualOut	2x IR3555 60A
ASUS ROG Crosshair VIII Hero (WI-FI)	+	+	+	+	7	DualOut	2x IR3555 60A
ASUS ROG Crosshair VIII Impact	*	*	+	+	4	DualOut	2x TDA21472 70A
ASUS ROG Strix X570-E Gaming	+	+	+	+	6	DualOut	2x IR3555 60A
ASUS ROG Strix X570-F Gaming	*	*	+	+	4	TripleO	3x SiC639 50A
ASUS ROG Strix X570-I Gaming	*	*	+	+	4	DualOut	2x TDA21472 70A
ASUS PRIME X570-PRO/CSM	*	*	+	+	4	TripleO	3x SiC639 50A
ASUS TUF GAMING X570-PLUS (WI-FI)	*	*	+	+	4	TripleO	3x SiC639 50A
ASUS PRIME X570-P	**	*	*	+	4	DualOut	2x SiC639 50A
ASUS TUF GAMING X570-PRO (WI-FI)	+	+	+	+	7	DualOut	2x SiC639 50A
ASUS ROG Crosshair VIII Dark Hero	+	+	+	+	7	DualOut	2x X95410RR 90A
ASUS ROG CROSSHAIR VIII EXTREME	+	+	+	+	9	DualOut	2x X95410RR 90A
ASUS ROG STRIX X570-E GAMING WIFI II	+	+	+	+	7	DualOut	2x FDMF3170 70A
ASUS ProArt X570-CREATOR WIFI	+	+	+	+	7	DualOut	2x FDMF3170 70A
ASUS TUF GAMING X570-PRO WIFI II	*	+	+	+	6	DualOut	2x SiC639 50A
ASUS Pro WS X570-ACE	*	+	+	+	6	DualOut	2x IR3555 60A
BIOSTAR Racing X570GTA	–	**	*	*	4	DualOut	SM4364/4377[1×2]
BIOSTAR Racing X570GT	–	**	**	*	4	True	SM4364/4377[2×1]
BIOSTAR Racing X570GT8	*	*	+	+	4	Doubler	1x IR3555 60A
Colorful CVN X570 Gaming PRO V14	–	**	*	+	4	DualOut	AON6354/6414A
Colorful CVN X570M Gaming PRO V14	–	**	**	*	4	DualOut	AON6354/6414A
Colorful CVN X570M Gaming Frozen V14	–	**	**	*	4	DualOut	AON6354/6414A
EVGA X570 DARK	+	+	+	+	7×2	Doubler	1x ISL99390 90A
EVGA X570 FTW WIFI	+	+	+	+
GIGABYTE X570SI AORUS PRO AX	*	*	+	+	4	DualOut	2x ISL99390 90A
GIGABYTE X570S AORUS PRO AX	+	+	+	+	6	DualOut	2x IR3555 60A
GIGABYTE X570S AORUS MASTER	+	+	+	+	14	True	1x TDA21472 70A
GIGABYTE X570S AERO G	+	+	+	+	6	DualOut	2x IR3555 60A
GIGABYTE X570 AORUS XTREME	+	+	+	+	14	True	1x TDA21472 70A
GIGABYTE X570 AORUS MASTER	+	+	+	+	12	True	1x IR3556 50A
GIGABYTE X570 AORUS ULTRA	+	+	+	+	6×2	Doubler	1x IR3553 40A
GIGABYTE X570 AORUS PRO WIFI	+	+	+	+	6×2	Doubler	1x IR3553 40A
GIGABYTE X570 UD	–	**	*	+	5×2	Doubler	4C06N/4C10N[2×1]
GIGABYTE X570 GAMING X	–	**	*	+	5×2	Doubler	4C06N/4C10N[2×1]
GIGABYTE X570I AORUS PRO WIFI	**	**	*	+	6	True	1x TDA21472 70A
GIGABYTE X570 AORUS ELITE WIFI	*	+	+	+	6×2	Doubler	1x SiC634 50A
GIGABYTE X570S AORUS ELITE AX	+	+	+	+	6	DualOut	2x IR3555 60A
GIGABYTE X570S UD	*	*	+	+	6	DualOut	2x SiC651C 50A
GIGABYTE X570S GAMING X	*	*	+	+	6	DualOut	2x SiC651C 50A
MSI MEG X570S ACE MAX	+	+	+	+	16	True	1x TDA21490 90A
MSI MPG X570S EDGE MAX WIFI	+	+	+	+	6	DualOut	RAA220075R0 75A
MSI MEG X570S UNIFY-X MAX	+	+	+	+	16	True	1x TDA21490 90A
MSI MPG X570S CARBON EK X	+	+	+	+	7	DualOut	RAA220075R0 75A
MSI MPG X570S CARBON MAX WIFI	+	+	+	+	7	DualOut	RAA220075R0 75A
MSI MAG X570S TOMAHAWK MAX WIFI	+	+	+	+	6	DualOut	2x ISL99360 60A
MSI MAG X570S TORPEDO MAX	+	+	+	+	6×2	Doubler	1x ISL99360 60A
MSI MAG X570 TOMAHAWK WIFI	+	+	+	+	6×2	Doubler	1x ISL99360 60A
MSI MEG X570 UNIFY	+	+	+	+	6×2	Doubler	1x IR3555 60A
MSI X570-A PRO	–	**	*	+	4×2	Doubler	4C024N/4C029N
MSI MPG X570 Gaming Pro Carbon WIFI	–	*	+	+	5×2	Doubler	1x QA3111N6N
MSI MPG X570 GAMING EDGE WIFI	–	**	*	+	4×2	Doubler	4C024N/4C029N
MSI PRESTIGE X570 CREATION	+	+	+	+	7×2	Doubler	1x IR3555 60A
MSI MEG X570 GODLIKE	+	+	+	+	7×2	Doubler	1x TDA21472 70A
MSI MEG X570 ACE	+	+	+	+	6×2	Doubler	1x IR3555 60A
MSI MPG X570 GAMING PLUS	–	**	*	+	4×2	Doubler	4C024N/4C029N

Table 2. B550 motherboard VRM ratings

Following the X570 chipset, the new B550 was introduced, which also performed very well. Some models feature equally high-quality power delivery systems. For example, the GIGABYTE B550 AORUS MASTER motherboard is even better than some X570 boards, and its VRM section is comparable to the X570S model. In this case as well, 6 — 7 phases are more than sufficient.

Model	200	175	150	125	Phases		Mosfet (SPS)
ASRock B550 Taichi Razer Edition	+	+	+	+	7×2	Doubler	1x SiC654 50A
ASRock B550 Taichi	+	+	+	+	7×2	Doubler	1x SiC654 50A
ASRock B550 Extreme4	*	+	+	+	6×2	Doubler	1x SiC654 50A
ASRock B550 Steel Legend	*	+	+	+	6×2	Doubler	1x SiC654 50A
ASRock B550 Pro4	–	–	**	*	3×2	Doubler	SM4336/37 [1×1]
ASRock B550 PG Velocita	*	+	+	+	6×2	Doubler	1x SiC654 50A
ASRock B550 PG Riptide	**	*	*	+	4	DualOut	1x SiC654 50A
ASRock B550 Phantom Gaming 4/ac	–	–	**	*	3×2	Doubler	SM4336/37 [2×2]
ASRock B550 Phantom Gaming-ITX/ax	**	**	*	+	6	True	1x SL99390 90A
ASRock B550M Steel Legend	–	**	*	+	4×2	Doubler	1x SiC654 50A
ASRock B550M PG Riptide	–	–	**	*	3×2	Doubler	SM4336/37 [1×1]
ASRock B550M Phantom Gaming 4	–	–	**	**	3×2	Doubler	SM4336/37 [1×1]
ASRock B550M Pro4	–	–	**	*	3×2	Doubler	SM4336/37 [2×2]
ASRock B550M/ac	–	–	**	*	6	True	1x SiC654 50A
ASRock B550M-HDV	–	–	**	**	4	True	SM4336/37 [2×1]
ASRock B550M-ITX/ac	–	–	**	*	6	True	1x SiC654 50A
ASUS ROG STRIX B550-F Gaming (WIFI)	*	+	+	+	4	Triple	3x SiC639 50A
ASUS ROG STRIX B550-XE Gaming WIFI	+	+	+	+	7	DualOut	2x X95410RR 90A
ASUS ROG STRIX B550-I GAMING	–	**	*	*	4	DualOut	2x SiC639 50A
ASUS ROG STRIX B550-A GAMING	*	+	+	+	4	Triple	3x SiC639 50A
ASUS ROG STRIX B550-E GAMING	+	+	+	+	7	DualOut	2x MP869902 70A
ASUS ProArt B550-CREATOR	*	+	+	+	4	Triple	3x SiC639 50A
ASUS TUF GAMING B550-PRO	*	+	+	+	4	Triple	3x SiC639 50A
ASUS TUF GAMING B550-PLUS (WI-FI)	**	**	*	*	4	DualOut	2x SiC639 50A
ASUS PRIME B550-PLUS	–	**	**	*	4	DualOut	SiRA12DP/14 [2×2]
ASUS TUF GAMING B550M-PLUS (WIFI)	**	**	*	*	4	DualOut	2x SiC639 50A
ASUS PRIME B550M-A (WI-FI)	–	**	**	*	4	True	SiRA12DP/14 [2×1]
ASUS PRIME B550M-K	–	–	–	**	4	True	SiRA12DP/14 [2×1]
ASUS TUF Gaming B550M (WIFI) ZAKU	**	**	*	*	4	DualOut	2x SiC639 50A
ASUS Pro B550M-C/CSM	–	–	–	**	4	True	SiRA12DP/14 [2×1]
ASUS TUF GAMING B550M-E WIFI	–	**	**	*	4	True	SiRA12DP/14 [2×1]
ASUS ROG STRIX B550-F Gaming WIFI II	*	+	+	+	4	Triple	3x SiC639 50A
ASUS PRIME B550M-A WIFI II	–	**	**	*	4	True	SiRA12DP/14 [2×2]
ASUS TUF GAMING B550M-PLUS WIFI II	**	**	*	*	4	DualOut	2x SiC639 50A
ASUS TUF GAMING B550-PLUS WIFI II	**	**	*	*	4	DualOut	2x SiC639 50A
BIOSTAR B550GTA	+	+	+	+	6	True	1x SL99390 90A
BIOSTAR B550GTQ	+	+	+	+	6	True	1x SL99390 90A
BIOSTAR B550MH	–	–	**	**	5	True	SM4364A/77 [2×1]
BIOSTAR B550M-SILVER	**	*	+	+	6	True	1x SL99390 90A
BIOSTAR B550T-SILVER	–	**	*	*	6	True	1x SL99390 90A
GIGABYTE B550 VISION D-P	*	+	+	+	6	DualOut	2x NCP25216 60A
GIGABYTE B550I AORUS PRO AX	**	*	+	+	6	True	1x ISL99390 90A
GIGABYTE B550 GAMING X	–	**	*	+	5×2	Doubler	4C06N/10N [1×1]
GIGABYTE B550M H	–	–	**	*	5	True	4C06N/10N [2×1]
GIGABYTE B550M GAMING	–	**	**	*	5	True	4C06N/10N [2×1]
GIGABYTE B550 AORUS PRO AC	*	+	+	+	6×2	Doubler	1x SiC651C 50A
GIGABYTE B550 AORUS MASTER	+	+	+	+	14	True	1x TDA21472 70A
GIGABYTE B550 VISION D	*	+	+	+	6×2	Doubler	1x SiC651C 50A
GIGABYTE B550 GAMING X V2	**	**	*	+	5	DualOut	4C06N/10N [1×1]
GIGABYTE B550 AORUS ELITE AX V2	*	+	+	+	6	DualOut	1x SiC651C 50A
GIGABYTE B550 AORUS ELITE V2	*	+	+	+	6×2	Doubler	1x SiC651C 50A
GIGABYTE B550M AORUS PRO-P	*	*	+	+	5	DualOut	2x SiC649A 60A
GIGABYTE B550M DS3H AC	–	**	**	*	5	True	4C06N/10N [2×1]
GIGABYTE B550 AORUS PRO V2	*	+	+	+	6	DualOut	1x SiC651C 50A
GIGABYTE B550M AORUS PRO AX	*	*	+	+	5	DualOut	1x SiC651C 50A
GIGABYTE B550M AORUS ELITE AX	–	**	**	*	5	True	4C06N/10N [2×1]
MSI MEG B550 UNIFY	+	+	+	+	14	True	1x TDA21490 90A
MSI MEG B550 UNIFY-X	+	+	+	+	14	True	1x TDA21490 90A
MSI MPG B550 GAMING CARBON WIFI	+	+	+	+	6×2	Doubler	1x TDA21462 60A
MSI MPG B550 GAMING EDGE WIFI	*	+	+	+	5	DualOut	2x ISL99360 60A
MSI MPG B550I Gaming Edge MAX WIFI	–	**	*	*	4	DualOut	2x MP86936 60A
MSI MPG B550 GAMING PLUS	**	*	*	+	5×2	Doubler	4C024N/29N [1×1]
MSI MAG B550 TOMAHAWK MAX WIFI	*	+	+	+	5	DualOut	2x RAA220075 75A
MSI MAG B550 TOMAHAWK	*	*	+	+	5	DualOut	2x ISL99360 60A
MSI MAG B550 TORPEDO	*	*	+	+	5	DualOut	2x ISL99360 60A
MSI MAG B550M MORTAR MAX WIFI	**	*	*	+	4	DualOut	2x ISL99360 60A
MSI MAG B550M VECTOR WIFI	–	**	*	*	4	True	4C024N/29N [2×1]
MSI MAG B550M BAZOOKA	–	**	*	*	4	True	4C024N/29N [2×2]
MSI PRO B550M-VC WIFI	–	–	**	*	4	True	4C024N/29N [2×2]
MSI B550-A PRO	**	*	*	+	5×2	Doubler	4C024N/29N [1×1]
MSI B550M-A PRO	–	–	**	*	4	True	4C024N/29N [2×1]
MSI B550M PRO-VDH WIFI	–	–	**	*	4	True	4C024N/29N [2×2]
MSI B550M PRO-DASH	–	–	**	*	4	True	4C024N/29N [2×2]
MSI PRO B550M-P GEN3	–	–	**	*	4	True	4C024N/29N [2×2]
NZXT N7 B550	*	+	+	+	6×2	Doubler	1x SiC654 50A

It is still too early to write off X470, B450, and even X370 motherboards. In our previously linked table, previous-generation models are listed, such as the ASUS ROG Crosshair VII Hero and the ASRock X470 Taichi, which are still relevant. Take a look at the AM5 platform as well — a VRM table for AM5 motherboards for the Ryzen 9600X, 9700X, 9950X, and others.

Conclusions

Marketing hype. For example, the VRM temperature of the Gigabyte X570 AORUS Extreme motherboard is 49 °C under a 125 W load. Meanwhile, the MSI MPG X570 GAMING EDGE WIFI reaches 96 °C. At 165 W, it goes up to around 130 °C, using a Ryzen 9 3900X at 4.2 GHz and 1.4 V, resulting in throttling. So much for how many power phases Ryzen actually needs…

More power phases result in a more stable CPU voltage. Total current increases through actual phases, doublers, or parallel MOSFET configurations. At the very least, good VRM cooling reduces power losses. Component quality is also important.