Four Multi-GPU Z77 Boards from $280-$350 - PLX PEX 8747 featuring Gigabyte, ASRock, ECS and EVGA

ECS Z77H2-AX In The Box

ECS bundles are often an unknown factor, given that ECS boards are not as frequent on our review schedule as some of the others.  Given our previous discussion regarding the price and the feature set, we hope that ECS can recoup some of the wow factor by providing a good deal.

Driver DVD
User Manual
Rear IO Shield
Six SATA Cables
Front USB 3.0 panel with rear bracket
SLI Fingers
Protective Caps for unused ports
WiFi Aerial

A surprising mix in the box – we are glad to see a full compliment of SATA cables for a Z77 motherboard above $300, as well as a USB 3.0 panel.  The protective caps included in the box are odd, as some other manufacturers also provide these but they come attached to the motherboard when shipped, rather than in a plastic bag in the box.  The WiFi aerial is also confusing, as it technically has nothing to connect to, like the antenna we get with Gigabyte motherboards or magnetic antenna with ASUS motherboards.

Voltage Readings

After my first publication of OCCT voltage readings, a few readers responded with a more in-depth reasoning behind some of the results we were seeing.  With this in mind, I would like to re-describe what we are doing with this test, and how it comes about.

Much of what an enthusiast overclocker does is monitor CPU temperature and voltage.  Whatever settings a user places in the BIOS or OS is at the mercy of the motherboard - in terms of actually setting the values and reporting the values back.   As an enthusiast, we have to rely on what readings we get back, and hope that motherboard manufacturers are being honest with their readings.

Take CPU voltage.  What we as a user see in CPU-Z or OCCT is a time-averaged value that hides voltage ripple (if any) for power delivery.  It is very easy for a motherboard manufacturer to hide this value, or to disregard slight deviations and report a constant value to the user.  The CPU voltage reading can be taken at a variety of places on the power plane, which can vary between motherboards and manufacturers, meaning that each reading is essentially not comparable with the other.  Nevertheless, as an enthusiast, we will constantly compare value A with value B. 

Whether or not I can achieve 4.7 GHz with 1.175 volts on a particular board is inconsequential - your motherboard may perhaps produce the same result with a reading at 1.200 volts.  The only way to test the actual value is with consistent methodology is via an oscilloscope connected to similar points on each board.  This may sound like taking an OCCT reading is therefore redundant.

However, motherboards have settings relating to load line calibration.  As load is applied to the CPU, the voltage across the processor decreases (VDroop).  Load Line calibration essentially attempts to control this level of droop, by increasing voltage when voltage drops are detected away from a fixed value.  Manufacturers have different ideas on how to modify LLC with respect to load, or whether the level of modification should be controlled by the user.  Some manufacturers offer the option at a variety of levels, such that overclockers can be sure of the applied setting (even if it increases peak voltage, as explained by AnandTech in 2007).

By doing a full load OCCT test, we are essentially determining both how aggressive the motherboard is reporting the CPU voltage under load and how aggressive load line calibration is performing (from the point of view of the user without an oscilloscope or DVM).  If someone has one of the motherboards we have tested and you have a different one, variations in load voltage should describe the offset you may require for overclock comparisons.

While nothing is relatively surprising with the OCCT reading for the ECS Z77H2-AX at stock while under load, I did notice a strange relationship between the voltage set in the BIOS and the voltage reported under load.  In the BIOS, if the option for VDroop is disabled, the motherboard should adjust the applied voltage to the processor under load to keep it as constant as possible to that set in the BIOS.  So if I set 1.200 volts in the BIOS, VDroop/Load Line Calibration should maintain that 1.200 volts at load.  This is not the case.  Here are a few set and observed voltages for this motherboard, with VDroop disabled:

- Voltage in BIOS: 1.100 volts
- Voltage in OS at load: 1.164 volts

- Voltage in BIOS: 1.125 volts
- Voltage in OS at load: 1.200 volts

- Voltage in BIOS: 1.200 volts
- Voltage in OS at load: 1.272 volts

The positive bias in the voltage readings is un-nerving.  If a user or system builder is used to placing a voltage and overclock on any other Z77 motherboard and attempts the same here, the system will actually apply another 0.064 to 0.075 volts.  This will lead to vastly increased temperatures, and perhaps cause overheating.  This should not be the case, and I feel that there is perhaps a distinct BIOS programming error here.