MSI RX580 8GB Samsung Mem Blower vs. Open Air Fan BIG Power Difference... WHY?

[letmebefrank]

Hello World!

I have two 6 GPU rigs mining Ethereum, both with MSI RX580 8GB cards w/ Samsung memory. All cards are one click bios modded and using the same OC settings on SMOS (1150 core MHz, 2050 mem MHz, 875 core uv).

The only difference between the two rigs is the fan style. One has single fan blowers, the other has dual open air fans.

Even with fan speed the same (50-60% on avg), the blower rig runs at about 100-120 watts higher than the one with open fans. Is this a known thing that blower cards use more power, or is there something else I can tweak to get the power usage down there?

This is my first post on the forum so lmk if need to add more details or if this is a noob question..

EDIT:
it appears the difference was only in software reporting. Output from the wattmeter shows they are more or less the same from the wall (~880 watts for reference). So the 2x open fan units underreport more in software whereas the blowers were dead on per readings in SMOS.

Thanks!

[batsonxl]

1 way to be sure plug wattmeter and read what you get from the wall. Sometimes even bios version can show different watts on screen. thats why you need measure it from the wall.

[miner29]

The watt meter (kill-a-watt) will give you the firm answer.
I think you will find the blower cards use a bit more power on the fan than regular 2x or 3x fan units.  The blower is a much higher static pressure than the little prop fans.

[letmebefrank]

1 way to be sure plug wattmeter and read what you get from the wall. Sometimes even bios version can show different watts on screen. thats why you need measure it from the wall.

The watt meter (kill-a-watt) will give you the firm answer.
I think you will find the blower cards use a bit more power on the fan than regular 2x or 3x fan units.  The blower is a much higher static pressure than the little prop fans.

Wow, bad assumption on my part that the two different card styles would report the same in software. Output from the wattmeter shows they are more or less the same from the wall (~880 watts for reference). So the 2x open fan units underreport more in software whereas the blowers were dead on per readings in SMOS.

Thanks for the help!