140mm Side Fan - Does NOTHING?

[flexy]

I have a great case, the Fractal Design Arc Midi 2. I got it with the solid side panel which has an opening for a side-fan.

I used the 3rd 140mm to mount on the side, blowing (in) right on my new EVGA GTX 970 SC ACX2.0

I could've sworn, back with my Gigabyte GTX 660 TI Windforce, the side-fan made a BIG difference, like at least 5 deg less on the GPU.

NOW on the GTX 970: NOTHING. Card gets to 72C with side fan or without, not a degree difference.

Alternatively I could mount the sidefan as a second intake in front, or as an intake at the botton, blowing up sort-of towards the card.

Anyone an idea why temps are now the same with or without side intake? Is my airflow already good enough so that a side-fan is pointless? This is the only thing I can think of.

(Second bottom front intake would be pointless too IMHO, HD cage on front bottom w/ 3 HDs is more or less entirely blocking the lower opening.)

 

[Jovec]

Anyone an idea why temps are now the same with or without side intake?

72C is the target temp for the card/drivers. Your extra side fan is probably allowing the GPU fan to spin slower (than without the side fan), but otherwise the GPU is working as intended.

 

[BonzaiDuck]

72C is the target temp for the card/drivers. Your extra side fan is probably allowing the GPU fan to spin slower (than without the side fan), but otherwise the GPU is working as intended.

I don't doubt what you describe there. Generally, I've found 72/73C to be a maximum for 2x GTX-970s configured for SLI. That temperature level comes from the top card, while the bottom card is about 7C lower.

There are default fan profiles with certain motherboards, or there is a set of profiles and one is the unconfigured default. With software like Afterburner, you can define different fan-curves for different cards. The way to test if a side-panel intake fan will improve cooling involves setting the fan curves so that they reach 100% duty-cycle at some known level, with an overclock pushes the temperatures higher than the threshold set in the fan-control configuration.

Then you can test the peak temperatures with and without the side-panel fan.

I tend to look at the problem differently. The side-panel vent is an opportunity to increase overall intake airflow, and with its own set of drawbacks. It defiles all or part of the possibility to have a smooth, sealed, tinted window to the case interior. YOu would have to build the side-panel window around the fan vent. Further, the sidepanels can transmit the vibration of fans attached to them, unless care is taken to isolate fan vibration from both the mounting surface and the mounting hardware. Ideally then, you would want to use rubber fan mounts. If not rubber fan mounts, you can use wire ties which are a flexible but stiff vinyl plastic, taking care to wrap the points of contact with acoustic foam padding before securing the wire tie.

Then there's the possibility of building a more solid fan frame, or a solid swinging door inside the sidepanel that holds the fans suspended on a spring-loaded hinge which also serves to isolate the vibration. The CM Stacker midtower cases used this idea.

All of these fan options require a little thought to wiring connections, noise-deadening, and for building the fan-frame-door and hinge mechanism -- concerns about the clearance inside the case with graphics cards and tower-heatpipes.

 

[rgallant]

I have a great case, the Fractal Design Arc Midi 2. I got it with the solid side panel which has an opening for a side-fan.

I used the 3rd 140mm to mount on the side, blowing (in) right on my new EVGA GTX 970 SC ACX2.0

I could've sworn, back with my Gigabyte GTX 660 TI Windforce, the side-fan made a BIG difference, like at least 5 deg less on the GPU.

NOW on the GTX 970: NOTHING. Card gets to 72C with side fan or without, not a degree difference.

Alternatively I could mount the sidefan as a second intake in front, or as an intake at the botton, blowing up sort-of towards the card.

Anyone an idea why temps are now the same with or without side intake? Is my airflow already good enough so that a side-fan is pointless? This is the only thing I can think of.

(Second bottom front intake would be pointless too IMHO, HD cage on front bottom w/ 3 HDs is more or less entirely blocking the lower opening.)

mostly I use the side cooling
for me on water I still run 4 x 120's [low speed GT's] on the side of my haf 932 to catch the hot places [mb,cards] that low speed air does not hit if I had any.
even the water blocks were picked for not being full blocks leaving the front ends of the cards bare [caps] to be open for that air cooling, instead of being covered .

 

[Valantar]

NOW on the GTX 970: NOTHING. Card gets to 72C with side fan or without, not a degree difference.

Have you looked into what click speeds the card maintains with and without the fan? The way I've understood it, the GTX 9XX series will run as high as the BIOS allows, within temperature and power limits. So, the fan might be letting it stay at a higher turbo bin for longer, at the same temps, no?

 

[Ketchup]

I have never seen a GPU drop temps with a side fan. Have tried several times. Since almost all active cooling video cards are designed for airflow from front to back, a cooling fan in the front of the case, if you use one at all, would be the best place for active GPU cooling.