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120mm front intake fan& pc cooling

By Herbssat
Oct 9, 2007
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  1. I recently built a computer with a Gigabyte GA965P-S3 mobo and an Intel Core 2 Duo E4300 and slightly overclocked it to 2.3 ghz. I decided to add a front case fan to see if that would get me a slight improvement in system temp and cpu temp. I benchmarked the system with the fan connected and without the fan connected. The better benchmark using SiSoft Sandra Lite was achieved by not connecting the front intake fan.In fact, the reading was 1 degree celsius better. I realize that all cases are not equal but the hot air theory does not seem to apply here. By the way; I do have another 120mm exhaust fan blowing the hot air out of the back. The power supply I use is a FSP 400 watt with the fan in the bottom of the supply. I need some other ideas on this one.
  2. Cinders

    Cinders TechSpot Chancellor Posts: 1,313   +12

    How many times did you run the benchmark with the fan in place? How many times did you run the benchmark with the fan out of place? Once or twice each isn't a good sample. I bet if you ran the benchmarks forty or fifty times each and then calculated the average benchmark score they'd be about the same, because one degree Celsius isn't going to make much difference.
  3. pdyckman@comcas

    pdyckman@comcas TS Rookie Posts: 718

    Try one of the Antec 'Spot Cool' fans. You can point it at anything Experiment with temporary locations with fans until you find the good places for your application. Vantec makes a good slot fan that employs 2 80 mm fans that run from 2400 to 4000 rpm. They are great for the right application.
  4. Herbssat

    Herbssat TS Rookie Topic Starter Posts: 64

    I appreciate the replies and I will look into these fans. After investigating the area of the front intake fan more closely; I concluded that there was no way the fan could intake air properly. One major obstruction is that the wiring for the front usb and audio ports passes right over the intake opening and instead of a more open wire grille, it has the normal restrictive grille that is metal with small openings. Furthermore, the dust filter located in the front of the intake looks to be blocking it also. In order to get this to work properly, this case will have to be modified for better front airflow. Are there any good case designs to promote maximum front airflow intake?
  5. Rayss523

    Rayss523 TS Enthusiast Posts: 121

    You should have more fan pushing air in than pulling air out, FYI.
  6. Row1

    Row1 TS Maniac Posts: 355   +8

    rays and others: evidence: pushing better than pulling?

    hello- is there any study out there that shows that blowing air into the box achieves more cooling than pulling air out?

    my thought is this:
    first, the OP has evidence to the contrary - although yes 1 degree might not be a big diff, and he needs to run more evals with more varied loads, etc.

    second: if you blow air in, you don't know where it goes or how soon - so the air could just keep getting hotter, even though it is moving around. -but if a fan pulls out whatever cfm, then you know for sure that air moved out of the case, and it is almost sure that the air getting moved out from inside the pc was hot, and that replacement air had to get back in the pc from somewhere, and was ambient temp when it got int othe pc. -Row1
  7. Herbssat

    Herbssat TS Rookie Topic Starter Posts: 64

    I appreciate all the replies to my thread. They are all very informative and interesting. However, as the last poster implied; more air intake into a case is not necessarily the answer to lowering cpu and system temps. In fact; I proved my theory with my particular case by adding a 120mm intake fan in the front with an airflow of 41.3 cfm and a side 90mm fan in the cpu air duct of about the same airflow. After doing a number of evaluations;I found that the temps got worse. In most cases, having more airflow and not having it strategically placed within the case actually disrupts the flow of air from front to back and causes hot air to remain in the case instead of exhausting it. I found that the best potential for cooling my case was achieved by adding a 90cfm 120mm fan in the front and ditching the side air duct fan. The original case design already had a rear 120mm exhaust fan. The only problem with the 90 cfm fan is that it is extremely loud. However, a fan controller can take care of that. The main point is that every case is different. You may follow the general rules of convection but experimentation and benchmarking are going to tell the story.
  8. Myzz617

    Myzz617 TS Rookie Posts: 382

    Well if you CPU has a heatsink ad fan...is ur case bigg enough to buy a liquid cooled heatsink....I kno HP sells them inside some of their MT's.
  9. pmfun

    pmfun TS Rookie

    cool nice :)
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