Specs
Busting
out the specs first.
| XFX 850W-BES | |
|---|---|
| Rated output power | 850W @ up to 50°C |
| Power specification | ATX12V 2.3/EPS12 v2.92 |
| Power switch | Yes |
| Efficiency | >85 per cent @
wide load |
| 80 PLUS certification | Silver |
| Input voltage (AC) | Auto-ranging 90-264v, 47Hz-63Hz |
| Fan(s) | 1 x 135mm (700-1,500rpm) |
| Operating temperature range | 0-50°C |
| Cable runs (pre-attached) |
1 x 24-pin EATX (split) 1 x EPS 8-pin 1 x EPS 4-pin + 4-pin 2 x 6+2 PEG |
| Cable runs (modular) | 2 x 6+2
PEG 2 x 4-pin Molex 2 x 4-pin Molex 2 x 4-pin Molex 2x 4-pin Molex 2 x 4-pin floppy 3 x
SATA |
| Max. currents |
+3.3V: 24A |
| Max combined 3.3V & 5V output | 150W |
| Dimension (W x H x L) | 150 x 86 x 170mm |
| Warranty | 5-year, limited |
| Price | £135.53 |
Analysis
The XFX 850W PSU is rated up to 850W with an ambient temperature of 50°C, matching other high-quality PSUs. Should a sudden power-requirement surge occur, the unit can run at 935W for at least one second.
Equipped with a single 135mm fan, manufactured for XFX by Adda, which can push a maximum airflow of 89.3cfm at 2,050rpm and 37.8dbA, cooling should be good. We expect the fan to run much quieter on a mid-load basis, of course.
Quoted efficiency is very good for a PSU in its class, rated at >85 per cent over a wide load that's defined as 20-100 per cent of total capacity. XFX goes further and states that efficiency rises to >88 per cent at 50 per cent load. As such, the PSU passes the 80 PLUS Silver classification criteria.
The unit has the usual gaggle of pre-attached cabling, including 24-pin power, dual 8-pin for the CPU, including servers, and a couple of 6+2 PEGs for graphics. The rest of the connectors are modular, and XFX provides a generous level of connectivity, ranging from 8 x 4-pin Molex to 11 SATA. Two-way (dual connectors) graphics-card setups are catered for by another couple of PEG connectors, and the omission of extra PEGs can be justified by the comparative lack of wattage.
Any modern PSU provides most of its power on the 12V line(s). XFX is no exception, of course, but chooses to do so with a single 12V rail rather than split them up into, say, six. A single-rail eliminates any overburdening of a particular line.
The dimensions of the PSU indicate that it should fit in most chassis, and its high-end origins are revealed with an etail price of £135, including VAT, which is £10 dearer than Corsair's HX850 but £30 cheaper than Enermax's REVOLUTION 85+ 850W. Warranty-wise, XFX backs it up with five years of cover that is now standard for premium-quality supplies.
The XFX 850W PSU is rated up to 850W with an ambient temperature of 50°C, matching other high-quality PSUs. Should a sudden power-requirement surge occur, the unit can run at 935W for at least one second.
Equipped with a single 135mm fan, manufactured for XFX by Adda, which can push a maximum airflow of 89.3cfm at 2,050rpm and 37.8dbA, cooling should be good. We expect the fan to run much quieter on a mid-load basis, of course.
Quoted efficiency is very good for a PSU in its class, rated at >85 per cent over a wide load that's defined as 20-100 per cent of total capacity. XFX goes further and states that efficiency rises to >88 per cent at 50 per cent load. As such, the PSU passes the 80 PLUS Silver classification criteria.
The unit has the usual gaggle of pre-attached cabling, including 24-pin power, dual 8-pin for the CPU, including servers, and a couple of 6+2 PEGs for graphics. The rest of the connectors are modular, and XFX provides a generous level of connectivity, ranging from 8 x 4-pin Molex to 11 SATA. Two-way (dual connectors) graphics-card setups are catered for by another couple of PEG connectors, and the omission of extra PEGs can be justified by the comparative lack of wattage.
Any modern PSU provides most of its power on the 12V line(s). XFX is no exception, of course, but chooses to do so with a single 12V rail rather than split them up into, say, six. A single-rail eliminates any overburdening of a particular line.
The dimensions of the PSU indicate that it should fit in most chassis, and its high-end origins are revealed with an etail price of £135, including VAT, which is £10 dearer than Corsair's HX850 but £30 cheaper than Enermax's REVOLUTION 85+ 850W. Warranty-wise, XFX backs it up with five years of cover that is now standard for premium-quality supplies.
