- Joined
- Jan 16, 2010
i stuck a second fan ontop of the stock fan on a hd 2600 xt 512.its exactly the same size an everything.smart or dumb? lol
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2 fan sandwich ?
- Thread starter danmna2626
- Start date
- Joined
- Jul 24, 2002
- Location
- Seattle, WA
Thinking about tests on this I've read in the past, it's not going to help you unless there's a spacer between them. The turbulence from one fan will offset the gain you'll see from the second.
Even if there is a spacer, it's only useful if you need a lot of air pressure. My guess is that the cooler on your video card won't benefit from the extra pressure.
The ultimate way to test it out is to see if your temps were higher or lower after the change.
Even if there is a spacer, it's only useful if you need a lot of air pressure. My guess is that the cooler on your video card won't benefit from the extra pressure.
The ultimate way to test it out is to see if your temps were higher or lower after the change.
- Joined
- Jul 24, 2002
- Location
- Seattle, WA
It might seem quicker, but I'd be surprised if it was moving much more air. It's probably just louder because of the increased turbulence.
- Joined
- May 15, 2006
It isn't moving air faster.
Putting two fans in series (that is, the output to one is connected to the input of another) does not increase CFM (cubic feet per minute) ratings, only pressure. Putting two fans in parallel (that is, next to each other like in some stock cases) will double the CFM, but the pressure remains the same. This is in a "perfect world". Meaning, bolting two fans together without any sort of design is likely to cause more harm than good. There was a thread here a while back that I'm sure would take me a year and half to find, but it came down to: "Don't bolt them together. If you want a high flow fan, buy one. If you want a high pressure fan, buy one." In addition, there was some discussion about the fans needing to be counter-rotating to get any appreciable gains.
Bolting those two fans together will reduce the total airflow/pressure and increase noise/power consumption. Not worth it.
- Joined
- Mar 27, 2011
- Location
- Soviet Mexico
To add to what has already been said, If the two fans are varying speeds. For example the stock fan is slower, and the second fan is faster. There is a high chance that the slower fan will start to block the flow and reduce the airflow.
Also some fans have wide cone areas that they pull air from, other have narrow bands where they pull air but create additional flow effects that complement and help them gather air. By putting something else in that area that might impede flow, you can end up harming the flow of these types of fans.
Also some fans have wide cone areas that they pull air from, other have narrow bands where they pull air but create additional flow effects that complement and help them gather air. By putting something else in that area that might impede flow, you can end up harming the flow of these types of fans.
OP
- Joined
- Jan 16, 2010
- Thread Starter
- #7
ok,sorry it took me a bit to get back to this.i just did some benching and WITH the 2 fans i got a steady temp of 75 whilst running ati tools 3d renderer for 15 mins or so.as soon as i took off the second fan the temp went up to 80+. kept the renderer runnig the whole time,put the second fan back on and it very quickly went back down to 75-74.so the verdict is that it actully does work fairly well inseed(as i had allready surmised)
OP
- Joined
- Jan 16, 2010
- Thread Starter
- #9
i somehow doubt that its more powerfull.its haerd to get at as iv buttoned the machine all back up and tucked it away again but the secondary fan is one of thoes rely thin fans like the ones you typicly find mounted on graphics cards and im powering it through a plug on the motherboard named"SYS FAN".
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- Joined
- May 15, 2006
There is another factor at play. You are making assumptions that are not correct. Yes, adding a fan may have reduced the temperatures, but that doesn't mean it proves physics wrong.
As I posted earlier, putting them in series increases the pressure of the fans in a perfect world. If there is enough resistance, adding a second fan may increase the pressure, which would mean that more air gets pushed through the heatsink.
Think of it like this: You have two vehicles and you bolt them together. It does not make them accelerate faster (CFM), but it will increase their total towing capacity (pressure).
OP
- Joined
- Jan 16, 2010
- Thread Starter
- #11
ya,that sounds reasonable. i wasnt so much arguing the physics of it as much as the result of it.the result being a considerable drop in GPU temps. i was thinking of it more like, because the air is allready sped up by fan 1 it will be easer for fan 2 to further increase airspeed. but the bolting 2 cars thing sounds good tho lol
It will work, i remember doing it many many years ago - putting a 120mm fan on stock Celeron 300A heatsink using a cardboard "cone".ya,iv never pulled apart the fan/heatsink assembly on this card but im sure i could prolly pull the stock fan out and strap on a big one with some kinda ducting i suppose
