A top-end PSU with digital voltage
control and monitoring
Developments in PSU tech generally happen
at a snail’s pace; a tweaked capacitor here, a redesigned coil there, all pushing
efficiencies slightly higher and allowing for marginally tighter voltage
regulation. However, Corsair’s AX1200i is the first PSU we’ve seen that’s
equipped a digital signal processor instead of the typical analogue circuitry
to control voltage stability and ripple.
Residing at the top of Corsair’s PSU
product line, the AX1200i is rated to a whopping 1,200W of load; enough to
power an overclocked LGA2011 system with several GPUs with room to spare. The
PSU is fully modular, with a hefty array of connectors. The 24-pin ATX power
cable, pair of 8-pin EPS12V connectors and sextet of individual 6+2-pin PCI-E
power connectors are all sleeved in black weave, while the 16 SATA connectors
(split between four cables) and 12 Molex connectors (split between three
cables) are sleeved in glued rubber coverings. This means that there are only
enough power connectors for triple-GPU setups though; those chasing Quad-SLI or
CrossFireX will need to break out the Molex to PCI-E connectors.
Corsair
AX1200i
With its 80 Plus Platinum efficiency
certification, the AX1200i uses a single massive 12V rail to supply the unit’s
full 1,204.8W of power. Thanks to the digital signal processor inside, the
AX1200i can also perform on-the-fly monitoring of the unit’s current power
consumption, voltages and amperages. This is accomplished via a com-port
connector on the PSU’s modular panel, which then connects to a USB 2 header.
Corsair’s Link software, which will expand to allow control of case fans and
CPU coolers too, then enables you to monitor many of your PSU’s functions, and
adjust the cooling fan’s rpm curves.
The software isn’t perfect though; it can
only measure efficiency accurately to within 5 per cent at loads over 300W, and
10 per cent between 100 – 200W.
Strapped to a Chroma-calibrated Chroma ATS
8000 automated PSU tester, the AX1200i had little trouble supplying its full
rated wattage, with a peak efficiency of 90.17 at 100 per cent load. Voltages
were well within the ATX specification too, but the unit’s ripple noise really
caught our eye. The peak variance in the voltage, the 12V ripple noise at 100
per cent load, was just 0.021mV – almost haft that of other high-end PSUs we’ve
tested. Of course, most other PSUs we’ve tested are still within the ATX
ripple-noise spec of 0.120mV for the 12V rail, but it’s clear that the
AX1200i’s DSP does its job well. The AX1200i’s 140mm fan is motionless below
250W, thanks to semi-passive cooling; it isn’t whisper-quiet when running but
neither is it intrusive.
Corsair’s
AX1200i is the first PSU we’ve seen that’s equipped a digital signal processor
Conclusion
The clearly very capable AX1200i can supply
its 1,200W of power at 80 Plus Platinum efficiency levels, and with the lowest
ripple noise we’ve seen. At $404, though, it’s a serious investment. The Be
Quiet! Dark Power Pro 10 850W is $129 cheaper, while 1,200W units with 80 Plus
Gold certification typically cost $64.5 less. However, if you need 1,200W, and
will accept the only the best, then the AX1200i is for you.
|
Information
Power: Stable voltages; very low ripple noise; exceeds 80 Plus Platinum
spec; loads of cables; user-adjustable fan-curves
Corruption: Corsair Link software not that accurate; expensive;
1,200W overkill for most people
Price: $402.9
Manufacturer: corsair.com
In detail
·
Size (mm): 150 x 86 x 200 (W x D x H)
·
Rated wattage: 1,200W
·
80 Plus Certification: Platinum
·
EPS 12V connectors: 2 x 8-pin
·
PCI-E power connectors: 6 x 6 + 2-pin
·
SATA power connectors: 16
·
Molex power connectors: 12
·
Warranty: Seven years
Scores
Stability: 40/40
Design: 28/30
Value: 16/30
|
