Before we examine the results, we should point out that all of the thermal images have been rotated so that the motherboard is in the traditional upright position to assist in visual comparisons. With that said, lets examine the results:
Additional note: some people have been inquiring about the blue dot in the middle of all the thermal images. This is the CMOS battery which apparently never gets hot even when the system is under very high load.
Coolit ECO II
For our first test, the results were somewhat underwhelming. Simply put, there is minimal difference between the system in a vertical or horizontal airflow orientation. The one degree difference in CPU temperatures is within our margin of error, and there are only a few minor differences in the thermal images. The thermal image for the vertical cooling shows only slightly better cooling to the MOSFET heatsinks and a single IC chip above the CPU under load. The thermal images are very close, but the one red IC chip on the horizontal load image is just enough for us to call the vertical configuration the winner.
Winner: Vertical cooling, but just barely
Gelid Tranquillo Rev2
With the Tranquillo CPU cooler, the results between the two orientations are identical. All temperature readings are within our margin of error, and the only differences between the thermal images are so slight that we are attributing them to camera angle or normal testing variances. So for this round, neither orientation has an advantage over the other.
Antec P183 V3
Coolit ECO II
The airflow in the Antec P183 V3 is much more restricted than the Silverstone FT02B-W so we expected the the differences between vertical and horizontal cooling to be more pronounced in the Antec P183 V3 testing. We ended up being correct, but not in the direction we anticipated. At idle, the temperature readings are the same between both orientations. The thermal images do however show slightly better cooling with the case in the horizontal orientation, with the chipset and MOSFET heatsinks as well as CPU radiator all running slightly cooler. While it is still somewhat minimal, it is definitely a larger variance than we saw in the Silverstone FT02B-W testing. At load, we finally got some clear results with the CPU running a full 7c cooler in the horizontal orientation. Given the vastly different CPU temperatures, we expected the thermal image variance to be larger than the idle images but they were surprisingly similar. The CPU radiator is indeed much hotter, but the chipset and MOSFET heatsinks are basically identical in the two images. The area to the left of the chipset is however much hotter in the vertical orientation than in the horizontal orientation.
Winner: Horizontal cooling
Antec P183 V3
Gelid Tranquillo REV2
While we were able to see temperature differences in the Antec P183 V3 with the Coolit ECO II comparisons, with the Gelid Tranquillo cooler there is absolutely no difference in cooling between the two orientations. There are a few variations in the thermal images, but most of them are actually caused by the slight height change when the case is turned on its side exposing slightly more of one component or another and not by any actual difference in temperature.