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- Date:
- Wednesday, January 14, 2009
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
Seasonic M12D-850 Power Supply
Seasonic is a common name to the computer hardware enthusiast that pays attention to his power supply. Seasonic in many ways has become the de facto standard when it comes to quiet PSUs. Today it states it is the new standard in silent computing. So what's new?
Overview
The first thing we are going to look at with the Seasonic M12D-850 is its packaging, accessories, and documentation. While normally none of these items is a make or break item for a power supply the packaging quite often contains a lot of information about the product we are purchasing. The inclusion of an owner’s manual that provides actual information about our product is also of great help. Accessories are almost unnecessary with a power supply as the unit is self contained, unless it is modular, but there cases where a manufacturer can include useful accessories to make installation, routing and use more efficient.
The Seasonic M12D-850 packaging's color scheme puts it right at home on Halloween night with its orange, yellow, and black motif. As is typical for most retail power supplies the box is covered in marketing points and a number of other helpful/interesting certifications or features. Among those found on this unit are the power table (reproduced below), an 80Plus Silver seal, Energy Star 4.0 seal, fan noise graph, a SLI ready seal, and a number of marketing points including that the unit has solid capacitors and a Sanyo Denki fan. Among these marketing points, the advertisement for the solid capacitors should not be confused to mean that the unit has all solid capacitors as that is not the case. Additionally, the unit advertised as having "DC to DC Converter Design" (for) "superior dynamic response & greater system stability." This is interesting as to date we have not seen a large difference in units with DC to DC VRM's in our Transient Load Testing but this is something we hope that Seasonic may have worked out along with the unit’s advertised "Tight Voltage Regulation" (for) "Improved load regulation to reduce voltage variations" which typically has not been amazing on units with DC to DC VRM's when we have looked at the minor rails in our testing. Moving on, the M12D-850 is advertised as being 80Plus Silver certified and indeed a quick check of the 80Plus website finds this to be true. Additionally, we have an SLI certification on the box but a quick check of the SLIZone website finds that the unit is not certified for any level of SLI at the time of writing. Lastly, the unit is advertised as having a 5 year warranty which is good to see and better than the 3 year warranties we have been seeing a lot of lately.
*Orientation of modular connectors is determined by having the fixed wiring on the user’s left hand side when facing the modular interface.
As we see from the above information the Seasonic M12D-850 is a bit of a mixed bag. The M12D-850 has a very high 12v capacity, relative to the unit’s total DC output capacity, as 70A is equal to ~99% of the unit’s output capacity spread across two 12v rails. It is rare that we see units in this power output range with dual 12v rails (a notable exception being the HX1000W but that unit is actually two 12v power supplies in one housing) and in this case the 12v rail layout is less than intuitive. Actually its downright useless, but no harm is done either. If you are going to current limit rails it might as well be in a manner that actually isolates the high draw components from one another, which this unit doesn't do in any way as we find PCI-Express connectors lumped with EPS connectors etc, or if not lets at least have a unit that actually has two real 12v sources. As it stands, the breakdown on this unit is annoying, undocumented for the user, doesn't adhere to the waived 240VA limitation, and provides no real useful purpose. As such, it would behoove Seasonic to just remove the OCP on this unit as they have done time and time again and make this unit a single 12v rail unit. Beyond those issues, the unit is well equipped with 8 Molex and 8 SATA connectors to make use of the unit’s generous 12v capacity along with the units 4 PCI-Express connectors.
Once we open the M12D-850 we find the usual assortment of items including the power supply, the power cable, mounting screws, modular cables in a bag, and the user manual. The user manual that comes with the M12D-850 is 28 pages along in 7 languages and has some information in it. Included in the manual is the power table, the connector count, derating information ("The rated power will reduce from 100% to 80% from 40C to 50C linearly"), and some basic installation instructions. Noticeably absent from the manual is the warranty information and the 12v rail breakdown. The lack of the 12v rail breakdown is particularly disappointing as the break down for this unit is not standards compliant and is NOT indicated on the unit in any way for the user to determine. Indeed, the rail breakdown is exceptionally convoluted, undocumented, and confusing to the point that even after requesting this information from Seasonic I was forced to trace it myself so that I could test the unit. Thankfully the leads on the PCB's were correctly marked (unlike the cables), but there will be more about this issue later. Overall, the manual is of some use but it is not the best and really falls down on the one critical area for this unit.