We've recently tested the first 80 Plus Platinum PSUs to hit our labs, courtesy of Seasonic and Enermax.
Both were good if expensive PSUs, and next up on the test bench is a
Platinum series that's sold by a brand without their own PSU factory:
XFX. They sent us their newest product, the Pro Series 80 Plus Platinum
Black Edition, which sets its sights on the high-end of the market. XFX
has created an interesting casing with some unusual elements, but we
need to find out how good this model acutally is.
While efficiency is all the marketing rage in the world of PSUs, we
should keep in mind that many manufacturers are trying to reach 80 Plus
Platinum levels using some "tricks". As we noted in our Seasonic
article, there are various routes to higher efficiency, like removing
resistors that may fill other roles. Shunt resistors for example
transform some of the power into power loss when current flows through
it, since there is a voltage drop. That's actually their job as they
measure and prevent overcurrent in an indirect way. So let's see how XFX
reached the requirements for 80 Plus Platinum (90%/92%/89% efficiency at 20%/50%/100% load), as well as look at how the XFX model fares in an increasingly crowded market.
XFX has historically tried to cater to gamers, and the external design
of the XFX Pro (as well as their other PSU lines) tends to go with an
angular and "futuristic" vibe. While the exterior may or may not appeal
to your gamer sense, ultimately it's what's inside that matters, and in
this case we can see that Seasonic provides the electronics (as you can
see from the picture below). We recently awarded Seasonic our Gold
Editors' Choice Award for the high quality PSU they provided and this
trend seems ready to continue. In any case, XFX made a good choice with
the manufacturer. This design offers low ripple and noise results on all
output voltages, high-quality capacitors from Japan, and several
technologies to increase efficiency. Even so, XFX changed some details
such as the fan for cooling.
The question then is whether XFX's design is as good as or even better
than the original Seasonic that we tested, and if the alterations made
to the core design change the product as a whole. In addition, we would
like to take the opportunity to let you know that we will be reviewing
some lower wattage Platinum PSUs soon; this will definitely be the last
1000W PSU for the first have of this half-year. Our next reviews will
test some 400W-500W power supplies from other brands that use more
common designs. Today however we will continue with our high-end testing
with the 1000W model from XFX. Besides, it's always interesting to see
what features can be implemented when the keeping prices down isn't the
primary concern.
Package Contents, Fan, and Power Rating
The contents of the package are not very generous this time. Besides a
relatively short user manual, two different power cords, and some
screws, XFX delivered the modular cables without any bag or cable ties.
Of course the electronics is much more important, but customers should
get more for the high price. Features of the product include the 80 Plus
Platinum certificate, a 5-year warranty, the "EasyRail Technology"
(single +12V output) and the "SolidLink Technology". The last item is a
nearly wireless connection to the modular PCB. In addition XFX says that
this PSU is ready for the most pretentious gamer PCs with CrossFire
certification, but that's hardly surprising given the wattage and
efficiency rating.
According to the label this PSU has a single +12V output rated at 83A,
which is quite a lot. Both +3.3V and +5V get fed by this output and are
specified at 25A each. Those outputs can provide up to 125W, which is as
high as the values we saw from Seasonic and more than sufficient for
all modern PCs, though older PCs might need more power here. The +5VSB
at 3A is also relatively strong.
The Protechnic MGA13512YF-025 is a good fan with a fluid dynamic
bearing (FDB is a kind of long-life version of the sleeve bearing), but
we'd like to see Sanyo Denki here. In this case the fan is sharp-edged
and more audible than the San Ace one. XFX could get Sanyo Denki without
any problems since Seasonic uses them as well. However, this version is
still better than the quality Yate Loon or equivalent that other
companies use. The fan is the only moving part in a PSU so it's nice to
see that XFX chose a FDB.
Appearance and Cable Configuration
The case is "the pride" of XFX. As you can see the ventilation holes
around the large power switch are square-shaped, and there are
additional ventilation slots on both sides. The fan grille goes for an
angular spiderweb aesthetic with the XFX logo at center. Most parts of
the case are made out of metal, while the front with the modular plugs
consists of a thin synthetic material. All the sockets for the modular
connectors have their own description, and while many manufacturers use
different colors to set the peripherial connectors apart from the PEG,
CPU, and motherboard connectors, this works just as well. XFX has a
video giving their thoughts on the design and elements of their new PSUs
below:
| Cables and Connectors | ||
| Connector type (length) | Main | 1x 24-pin (60cm) modular |
| ATX12V/EPS12V | 1x 4+4-pin (65cm) modular 1x 8-pin (65cm) modular |
|
| PCIe | 2x 6/8-pin (60cm) modular 2x 6/8-pin (60cm) modular 2x 6/8-pin (60cm) modular |
|
| Peripheral | 3x SATA (ca. 55, 70, 85cm) modular 3x SATA (ca. 55, 70, 85cm) modular 3x SATA (ca. 55, 70, 85cm) modular 2x SATA (ca. 35, 50 cm) modular |
|
| 3x Molex (ca. 55, 70, 85cm modular 3x Molex (ca. 55, 70, 85cm) modular 2x Molex (ca. 35, 50cm) modular 1x Molex to 2x FDD adapter (15 cm) modular | ||
As far as the connectors go, all of the cables are 60cm or more long
which will be good for larger cases. Naturally, a PSU in this wattage
should come with plenty of connectors and long cables, but it is very
impressive to see the heap of modular cables in the package. Like the
Seasonic, all of the cables are modular and the two FDD connectors
listed in the table above are implemented as an adapter. This method
allows the customer to realize an absolutely individual cable
configuration for their PC.
Both the two CPU and the three PCIe cables have a hugely satisfying
wire cross-section (16 AWG). Eleven SATA and eight Molex connectors are
more than enough to power any computer. We should note that the Platinum PSU from Enermax offers twelve SATA plugs; nevertheless, the number of cables and connectors is adequate for a 1000W model.
Seasonic builds this particular power supply and uses the full bridge
with a resonant circuit behind. The full bridge is composed of two half
bridges (one high-side and one low-side MOSFET each) which work
alternately so the transformer can be driven into a balanced state. This
full bridge allows them to reduce the size of the main transformer and
theoretically doubles the possible output power of the half bridge
converter. This only applies when identical MOSFETs are used and if all
other components are chosen correctly as well. As you can see the
heatsinks on the secondary side are very thin, but the MOSFETs have a
low power dissipation and get cooled by the conduction path and the fan
as well. Those blue capacitors beside the heatsinks are made by Nippon
Chemi-Con, as are all the others in this PSU.
The EMI filtering consists of a complete mains filter with two
additional X capacitors, four Y capacitors, one more common mode choke,
and one differential mode choke. Moreover inrush current gets limited by
a thermistor, and a MOV as passive OVP is included as well. Both
rectifier bridges get their own heatsink for cooling. In the power
factor pre-regulator we find three large main caps and a serperate IC
for PFC control on a single sided PCB. On the fifth picture in our
gallery, two MOSFETs in a large TO-247 case can be seen. Their gate
connectors are equipped with a ferrite bead. Besides this the PFC diode
on the left has nearly no reverse recovery time.
The resonant circuit in the middle shows one important change. Two
conductions of the IC CM6901 (on a small PCB) lead to a small inductor,
which is located between the resonant capacitor, the resonant coil, and
the small "auxiliary coil" to relieve the main transformer. With this
the current can be measured in the resonant circuit to improve
regulation. A second winding is connected to the main PCB and the
magnetic flux in the core passes through the regulation winding.
The buck converters for +3.3V and +5V are located on the modular PCB.
With the APW7159 controller XFX is able to switch at a high frequency.
With this the size of passive components can be reduced again. +12V has
many short transitions to the modular board, which means resistance is
somewhat lower; this helps to increase efficiency a little. The
protecion IC can be found on another seperate PCB on the left. As
expected XFX has a native dual output design for +12V. Soldering quality
is outstanding, as is usually the case with Seasonic built PSUs. We
couldn't find any dry soldered joints, though a few parts did get a bit
too much solder.
Voltage Regulation
The +12V voltage regulation is tight, while the weaker +5V ouput drops
to 1.84% below the optimal level. Nevertheless, all of the voltages are
well within the ATX specification. Moreover there is hardly any ripple
or noise on the outputs. They're always under 25mV and there are no
remarkable spikes or transients. There's definitely some nice work here
and the results are very close to what we measured on the Seasonic PSU.
With 80 Plus Platinum certification, we expected high efficiency and
the XFX model delivers. Efficiency is always above 80% and 80 Plus
Platinum is no problem for this design. Maximum efficiency comes at 50%
load as always. Worst-case efficiency at low load (5%) is still 80%, so
we really can't complain. With 92.74% XFX is only slightly lower than
the 860W PSU from Seasonic--easily within the variance we're likely to
see from either PSU.
The power factor is also satisfying, staying above 0.816. That might
not be the best result for low load, but any high-end system requiring
the XFX Pro Series should be running loads higher than that. During all
loads the fan noise is acceptable if not optimal. We didn't hear any
noise from the chokes. Of course the fan's RPM and the load rise
equally, which is one reason why we can't criticise a strong fan noise
at 80% load. Furthermore the features include two different modes for
controlling the fan speed—the fan can be turned off through up to 40%,
making the PSU inaudible (just like the Seasonic 860W).
Conclusion
It's no surprise that XFX does well in our tests, as they build off of
the core Seasonic design and the only major differences come in the
realm of aesthetics. With a very high efficiency and low ripple during
all loads, XFX delivers a high-end power supply without any noteworthy
flaws. The unique case design may require some getting used to for some
customers, but the thick-walled sides prevent electromagnetic
interference and some customers will certainly like the bit of flare it
adds in a windowed box. Our one minor complaint is with the plastic
elements on the modular conncetors; the original from Seasonic is
slightly better in this area.
XFX offers many connectors and the cable length is good. Beyond that
the electronics consist of a well known Seasonic design. The XFX Pro
Series might not be the best solution for bargain hunters, but without
doubt it is suitable for any enthusiasts who wants to get the best
quality money can buy. The internal design consists of a powerful
variation on the efficient resonant converter that allows zero voltage
switching. The manufacturer implements a silicon carbide diode without
any (or negligible) reverse recovery charge. The PSU is very well
equipped with a high-quality mains filter and further components for EMI
filtering . As expected XFX uses expensive Japanese capacitors from
Nippon Chemi-Con and the PCB consists of epoxy resin and fiberglass.
Again Infineon MOSFETs are one reason why this PSU is so efficient, and
the regulation circuit also received some improvements.
XFX didn't use many long cables to connect 12V with the modular PCB,
even if their advertising slogans overdo things a little. There are
still a few cables for the upper plug row. We also mentioned the low
power output on the +3.3V and +5V rails, but this is not necessarily a
disadvantage. As always, the required power depends on the system.
The voltage drops under high load are absolutely acceptable. These are a
reflection of the sizing of all the components. This design is able to
deliver much more than 1000W in a peak situation. +5V was at -1.84% during overload, and +3.3V
demonstrated even better results. In addition there is hardly any
voltage drop on +12V. A low output ripple and noise is very welcome as
well. +12V was at about 25mV while +5V and +3.3V stay below 20mV.
Overall efficiency is slightly lower than the results we have saw from the smaller 860W Seasonic PSU.
The 1KW design is able to barely surpass the 860W design at 5% load
(though that's comparing 50W to 43W), but it's only a 0.18% difference.
In all other cases the 860W PSU is a bit more efficient, especially at
10% load where it reaches 86.5% efficiency compared to 84.3%, but in
general the differences are minor and within the margin of error. More
importantly, both products perform very well, and unlike the Seasonic
860W we didn't hear any noise from the electronics this time.
A minor complaint is that the package contents aren't as extensive as
some of the competition. We'd like to see a seperate bag for the modular
cables as well as some cable ties. That's one reason to buy Seasonic if
you care for such amenities. XFX offers exactly the same cables as
Seasonic, and with six 6/8-pin GPU plugs and elven SATA connectors this
PSU is very well equipped (though the Enermax Platimax 1000W does have
one more SATA plug if such things matter to you). It's also nice to see
the FDD connectors realized as an adapter, and like the Seasonic the
option to have the fan run passively at <40% load is a nice feature
if you don't need the airflow a PSU can provide. Overall the list of
features is very good.
The direct 80 Plus Platinum alternatives come from Seasonic, SuperFlower and Enermax. If you prefer to shop at Newegg, the Platinum 1000W from Seasonic is more expensive than the version from XFX.
For the difference ($17 USD) customers get a better fan, 7 years
warranty and a few extras such as cable ties and a bag for the unused
cables. The main decision will really be which case you find more
appealing. The Kingwin LZP-1000
is the cheapest 1000W platinum solution (out of stock at Newegg as of
this writing), but they have fewer Molex connectors and EMI filtering is
slightly worse. The Enermax Platimax EPM1000EWT is by far the most expensive option and offers OCP—that's not to be taken for granted. Shopping elsewhere we can find the Seasonic 1000W, XFX 1000W, Kingwin 1000W
all going for the same $230 while Enermax still tips the scales at
$280. All in all XFX is able to provide a very good product that is
nearly as good as the original from Seasonic. For the same price we'd
still go for the Seasonic (for the better fan), but personal taste in
design as well as pricing will likely be the deciding factor.
