Doing the Math on ECO

On MSI’s website, a number of statements are made by their internal testing.

One picture shows a regular MSI mATX motherboard based on a low cost design drawing 29W. It does not state if this is idle, load or what CPU is used, but based on our testing it could easily be idle numbers with a reasonable CPU and a discrete GPU installed.

Next to the 29W number is an ECO motherboard indicating it uses 22W. Next to this is the same motherboard but with ECO Center software enabled, and 17W being used. MSI’s 40% claim of power reduction comes from the difference between 17W and 29W (~41%). Any company publishing numbers on its own products have a vested interest in making them sound as good as possible, so I took these numbers to run a regular working year analysis on them. Follow the math with me, and see if you agree with my conclusions.

  • Normal motherboard uses 29W
  • ECO motherboard uses 22W, which is 7W fewer
  • ECO with ECO Center software uses 17W, which is 12W fewer

The standard working year is 1920 hours long (8 hours per day, 5 days per week, 48 weeks per year).

This means that each motherboard uses the following amount of energy:

  • Normal motherboard at 0.029 kW for 1920 hours uses 55.68 kWh
  • ECO motherboard at 0.022 kW for 1920 hours uses 42.24 kWh
  • ECO motherboard with Software at 0.017 kW for 1920 hours uses 32.64 kWh

At a price of $0.12 per kWh, this means that:

  • The normal motherboard costs 55.68 * $0.12 = $6.68 per year to run
  • The ECO motherboard costs 42.24 * $0.12 = $5.07 per year, a saving of $1.61
  • The ECO+S motherboard costs 32.64 * $0.12 = $3.92 per year, a saving of $2.76

So by using MSI’s own numbers, an ECO motherboard with ECO center enabled would save $2.76 per year. If we extend that to a 3 year upgrade cycle (based on warranty), that means that the ECO motherboard should only cost an $8.28 maximum difference over the base board. MSI told me that the ECO range would cost 20% more than the standard range, and if that number is accurate, it means that the non-ECO boards should only be $41.40 ($8.28 / 0.2), and the ECO boards should be $49.88 maximum. If MSI were to move on to a five year warranty and this would extend to $13.82 in savings, a $69.12 base price and an $83.94 ECO price.

One quick blast to Newegg shows that the B85M ECO is on sale for $73.

One of the big problems with marketing components like motherboards as ‘eco-friendly’ is that when we are dealing in sub 10W savings, the cost of the extra components can vastly out-weigh the savings unless the product cycle is extended and supported accordingly.

Another interesting point to note is MSI’s quoted effect of the ECO Center software at load. Here MSI quotes 52.1W for an ECO motherboard at load which drops to 50.1W when the ECO Center software is enabled. It comes across a small drop, but that it important when it comes to our numbers.

Our Numbers

While MSI doesn’t state which motherboard they used to get the 29W value, we recently reviewed the MSI Z97I AC and thought that would be a good starting point. Being a mini-ITX motherboard it should have fewer components, but it is in the $140 price bracket and thus has a controller or two.

Normally we do our power readings with the same power supply across all motherboards. This means that while the numbers might be a bit inefficient at the lower part of the spectrum, they are all on the same efficiency line. Using our stupidly overpowered 1200W Gold power supply (for example) and an i7-4770K, the comparison between the Z97I AC and the B85M ECO gives:

Peak Power Consumption w/GTX 770 Equipped
Long Idle 56W 47W
Peak CPU Load (OCCT) 154W 129W

Even if you ignore the power efficiency, we have a 9W difference at idle and a 25W difference at load, which both works out to around 16%.

If we extrapolate 9W out in our mathematics, this equates to $1.84 a year, whereas 25W is $5.76. The more you load up the ECO system, compared to another loaded system, the more savings are to be had is a perfectly valid qualitative conclusion. The ECO certainly scores top marks in our standard motherboard power tests, coming top of our Z97 series by a good margin.

We tested the B85M Eco with four CPUs and two different power supplies with and without a discrete graphics card to get an understanding of how the power savings work. The power supply here is a 500W Platinum unit from Rosewill. All numbers given are peak power readings at the wall for the system as a whole.

Power Consumption w/GTX 770

Power Consumption w/Integrated Graphics

Our testing shows that the ECO mode affects a 1-2W difference in peak loading, but this correlates with MSI’s own numbers when using an ECO board vs. using the ECO board with the software enabled.

It was interesting to see that when the integrated graphics were in play, the i7-4770K downclocked to 3.3 GHz to hit the 85W mark. If we directly compare the POV-Ray results of each CPU in normal and ECO mode, the T/S processors stay within 2% but the 4770K reduces significantly enough to be noticeable:

POV-Ray Results
BIOS Defaults
in ECO Mode
i3-4130T 605 596
i5-4570S 1205 1186
i7-4790S 1336 1333
i7-4770K 1541 1412

MSI claims 100% performance at all times, but our i7-4770K CPU did reduce in frequency to hit the power point. We passed our information on to MSI although we are waiting on an official response. Chances are this behavior will be fixed in a future BIOS update.

MSI B85M ECO Overview, Visual Inspection, Board Features MSI B85M ECO BIOS
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  • Jaaap - Wednesday, November 26, 2014 - link

    For these ECO boards it would be very interesting to get and idle power for a setup without external videocard.
  • Jaaap - Wednesday, November 26, 2014 - link

    Arg i should read better: 21W minimum
  • klagermkii - Wednesday, November 26, 2014 - link

    Thanks for showing separate idle and load power usage in the review and not just delta.
  • bill.rookard - Wednesday, November 26, 2014 - link

    The area I think where this would do fairly well would be as a SMB server. I know I tend to keep things for far longer than 5 years which would be the break even point on the cost - once they have something that works, and works well (and works correctly) they'll leave it in place until it dies, and for something as simple as file serving, you just want something durable and reliable.
  • mike_m_ekim - Friday, December 12, 2014 - link

    Another great use is a HTPC. My HTPC uses a 35-watt haswell CPU. Passive cooling isn't an option because of location, so fans are required. Another 10 watt reduction in system heat would allow the fans to run just a little slower, making my nearly silent PC even quieter.
  • mike_m_ekim - Friday, December 12, 2014 - link

    One other thing, my HTPC is on 24/7 and transcoding almost all the time. I would see a $25 savings in electricity over 3 years, and an HTPC should be able to last much longer (because it's just an appliance). The cost savings would be secondary (noise being the biggest factor).
  • MrSpadge - Wednesday, November 26, 2014 - link

    My PC is number-crunching 24/7, so saving 12 W would save me about 6€/year (yeah, no fracking in Germany). A Z97 ECO could be interesting, because even with massive undervolting to ~1.0 V, current Intel CPUs are still asking to be OC'ed to ~4.0 GHz. I couldn't do that with a B chipset.
  • DanNeely - Wednesday, November 26, 2014 - link

    Is your math right? Your cost saving number seems low. For 24/7/365 operation a 1W load corresponds to 8.76 kwh/year; at an electricity price of 11.5 cents per kwh (reasonably close for most of the US) it works out as a dollar per wattyear or $12/year savings. My understanding is that German electric prices are several times higher, and am wondering if you lost a zero in your calculations.
  • Jaaap - Wednesday, November 26, 2014 - link

    You're right. One WattYear is approx 2 euro.
  • MrSpadge - Wednesday, November 26, 2014 - link

    8.76 kWh for 11.5 US-ct -> 1 W = 1 $/year in the US
    8.76 kWh for 23 EUR-ct -> 1 W = 2 €/year in Germany

    ... the cost is higher over here, but not an order of magnitude :)

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