ASUS M4A785TD-V EVO and M4A785TD-M EVO AM3 Motherboards Review

Voltage and Thermal Testing

Most people don’t realize that stable system power is the responsibility of more than just the PSU. A motherboard is essentially a complex power supply on its own, converting 12V and other supplied voltages to the required outputs for various system components. We’ll be validating the M4A785TD-V’s “dialed in” voltages in the BIOS using a digital multimeter.


M4A785TD-V EVO

For this particular test, we enabled all four cores on our CPU and left the frequency at the default 3.1GHz.
First and foremost, we’d like to say just how fantastic ASUS’ load calibration options are. Not only can you enable LLC, but you can fine tune it to your liking.


As you can see above, we fiddled with LLC until we got to a point of almost zero droop. The magic number for us was the 19% setting. Not only can droop be completely eliminated with the M4A785TD-V, but voltage set points are quite accurate as well. For those curious, the “AUTO” setting is actually 51% LLC.

We noticed that several software applications, including CPU-Z display a fair bit of vCORE variability with a constant load on the CPU, but this was not the case when reading from a DMM. Please take software readings with a grain of salt as this board rocks out some very stable CPU power – even at above 1.6V.


It is unfortunate that ASUS doesn’t provide more information on their LLC setting, as it was a bit confusing to us at first. One would assume that 100% LLC means that vdroop should be eliminated. As you can see above, the opposite was true. Setting this to 100% makes voltage droop horribly – even at idle. A setting of 1.65V only yields 1.493V in actuality. Moving to the opposite end of the spectrum yields the opposite problem. Voltage actually increases with load instead of drooping. So if you don’t feel like tinkering with LLC, go ahead and dial in the magical number of 19%.

ASUS’ implementation of LLC makes the M4A785TD-V an excellent choice for those looking to overclock their quads.


M4A785TD-M EVO


Voltage regulation on the M4A785TD-M was equally impressive, thanks to similar LLC functionality as well.



Thermal Performance

To test the effectiveness of the EVO passive cooling solutions, we conducted some basic temperature measurements using a digital thermometer. Although there are built-in temperature probes on both the “M” and “V”, we were unable to determine their exact location and questioned their accuracy. We attached our probe to the heatsink on the 785G heatsink, Southbridge as well as the MOSFETS area. All clock frequencies were left at their default values for this particular test. Ambient temperature was a cool 18 degrees Celsius thanks to December weather in Toronto

Full system load was achieved using Prime95 “Large FFT” testing while “Furmark” was run to get the integrated GPU all toasty. For the best effect, we wanted to measure temperatures in a less than ideal cooling environment. To accomplish this, we disconnected our Tech-Station side fan, and let the motherboard heatsinks run entirely passively. Our Noctua NH-U12P provides a small amount of collateral airflow to the MOSFET heatsink, but very little in comparison to a case with good circulation. Do note that this is a worst case scenario.


As expected, the smaller heatsinks on the “M” don’t quite cope as well as the full-sized “V”. None the less, all heatsinks did their job admirably, getting very hot to the touch at full load. Although this may not sound like a positive thing, it is because heat is successfully transferring from the chip, through the interface material and into the heatsink.