be quiet! · Power Supply Unit

be quiet! Pure Power 12 M price in United Kingdom

MPN BN343MPN BN344MPN BN342EAN 4260052189481EAN 4260052189498

Noise25.7 dB
ColourBlack
Total power850 W
Motherboard power connector20+4 pin ATX

Lowest price incl. delivery

£88.99

at Back to the OfficeFree deliveryIn stock

1 store
Range £88.99 – £149.99
Save up to £61.00 vs. the dearest store
1 in stock
1 with free delivery
Checked 6 Oct 2026, 05:40 UTC

Go to Back to the Office See all 5 offers

Ad · prices and stock as last reported by the store; the store's checkout is what counts.

Full specifications and side-by-side comparison

Prices in United Kingdom

1 store · prices in GBP · updated 6 Oct 2026, 05:40 UTC

Lowest price£88.99at Back to the Office · free shippingGo to Back to the Office

Price range across 5 offers

Save up to £61.00 (41%) by choosing the cheapest store

1 of 1 stores in stock
1 with free shipping
Checked 6 Oct 2026, 05:40 UTC

Back to the OfficeLowest pricebe quiet! Pure Power 12 M power supply unit 550 W 20+4 pin ATX ATX Black In stockFree shipping
£88.99incl. free shipping
Go to store : Back to the Office (opens in a new tab)
Back to the Officebe quiet! Pure Power 12 M power supply unit 750 W 20+4 pin ATX ATX Black In stockFree shipping
£113.99incl. free shipping+£25.00 (28%) vs lowest
Go to store : Back to the Office (opens in a new tab)
Back to the Officebe quiet! Pure Power 12 M power supply unit 650 W 20+4 pin ATX ATX Black In stockFree shipping
£113.99incl. free shipping+£25.00 (28%) vs lowest
Go to store : Back to the Office (opens in a new tab)
Back to the Officebe quiet! Pure Power 12 M power supply unit 850 W 20+4 pin ATX ATX Black In stockFree shipping
£128.99incl. free shipping+£40.00 (45%) vs lowest
Go to store : Back to the Office (opens in a new tab)
Back to the Officebe quiet! Pure Power 12 M power supply unit 1000 W 20+4 pin ATX ATX Black In stockFree shipping
£149.99incl. free shipping+£61.00 (69%) vs lowest
Go to store : Back to the Office (opens in a new tab)

Ad: we may earn a commission when you buy through these links; it never changes the order, which is by total price only. Prices and stock are shown as each store states them, as of 6 Oct 2026, 05:40 UTC, and can change at any time. Taxes are included only where the store includes them.

Price history in United Kingdom

Price history is being collected. After 14 days of prices we will show whether today's price is good.

Best price · Back to the Office£88.99

Go to store

Product details

Identification

Brand: be quiet!
Product: Pure Power 12 M
Full name: be quiet! Pure Power 12 M power supply unit 850 W 20+4 pin ATX ATX Black
Manufacturer part number: BN343, BN344, BN342, BN341, BN345
EAN / UPC: 4260052189481, 4260052189498, 4260052189474, 4260052189771, 4260052189467, 4260052189504
Category: Power Supply Unit

65 specifications from the manufacturer's data sheet

Power

Total power	850 W
Peak power	900 W
AC input voltage	100 - 240 V
AC input frequency	50 - 60 Hz
Input current	12 / 6 A
Power factor	0.98
Power Factor Correction (PFC) type	Active
Combined power (+3.3V)	120 W
Combined power (+12V)	850 W
Combined power (+5V)	120 W
Combined power (-12V)	3.6 W
Combined power (+5Vsb)	15 W
Max output current (+3.3V)	22 A
Max output current (+12V)	70.9 A
Max output current (+12V1)	40 A
Max output current (+12V2)	36 A
Max output current (+5V)	22 A
Max output current (-12V)	0.3 A
Max output current (+5Vsb)	3 A
Efficiency	93.2%
Power Good signal delay range	100 - 150 ms
Power protection features	Over current, Over power, Over voltage, Overheating, Short circuit

Ports & interfaces

Motherboard power connector	20+4 pin ATX
Motherboard power cable length	55 cm
Number of PATA power connectors	2
Number of SATA power connectors	6
SATA power cable length	500,600,650,800,950 mm
Peripheral (Molex) power connectors (4-pin)	1
Peripheral (Molex) power cable length	550 mm
EPS power connector (8-pin)	Yes
EPS power connector (4+4 pin)	Yes
PCI Express power connectors (6+2 pin)	4
ATX power connector (20+4 pin)	Yes
PCI Express connector	Yes
Cabling type	Fully-Modular

Performance

Purpose	PC
Power supply unit (PSU) form factor	ATX
80 PLUS certification	80 PLUS Gold
ATX version	3.1
EPS version	2.92
Noise level	25.7 dB
Mean time between failures (MTBF)	100000 h

Design

Product colour	Black
Cooling type	Active
Fan diameter	12 cm
Number of fans	1 fan(s)
Fan location	Top
Illumination	No
On/off switch	Yes

Operational conditions

Operating temperature (T-T)	0 - 40 °C

Packaging content

Cables included	PATA, PCIe, Peripheral (Molex), SATA

Certificates

Compliance certificates	RoHS

Weight & dimensions

Width	160 mm
Depth	150 mm
Height	86 mm

Packaging data

Package type	Box

Technical details

Sustainability certificates	ENERGY STAR, ErP
Sustainability compliance	Yes

Logistics data

Warranty period	10 year(s)

Other features

Screws included	Yes
Number of screws	5
Cable ties included	Yes
Noise level (silent mode, <30%)	9.4 dB
Noise level (quiet mode, 50%)	9.5 dB
Noise level (full-load mode, 100%)	25.7 dB