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Side Panel Fans: Are They Worth It?

Written on September 2, 2011 by Matt Bach


While there are many chassis available that provide more than enough cooling for even the hottest hardware, there are often reasons why one of those chassis may not be usable. It may be something as simple as aesthetics, or maybe your hardware simply won't fit in the chassis. In these scenarios, you can often take a chassis that otherwise is perfect for your system and modify it slightly to improve the cooling.

In this article, we will be looking at the advantages of adding a side panel fan from a pure cooling perspective. While adding a fan to a system will slightly increase the noise level of the system, for this article we are going to ignore that aspect for the sake of simplicity. A fan mount can be modded onto almost any side panel, although panels with layers of materials (like the Antec P183 V3) are slightly more difficult due to the thickness and the tendency of the layers to separate during the cutting process.

For our testing, we decided to use the Antec P183 V3 for two reasons. First, it is one of our more popular cases at Puget Systems, so this testing will directly benefit many of our systems. Second, it is a case that is designed for quiet operation and is not known for having amazing cooling. If we started with a high-airflow case that already has great cooling, it would be difficult to measure any temperature variances the side panel fan may create.

Our test system will be largely the same as the system in our Vertical vs. Horizontal Case Cooling article so that we will be able to get a few extra data points without having to do any additional testing. The two large differences are that the PSU was changed to a more common PSU for this case and that the Coolit Eco II was configured as an intake (which is our default configuration).

Testing Hardware:

Motherboard: Asus Rampage III Formula
CPU: Intel Core i7 980X
RAM: 3x Kingston HyperX DDR3-1600 4GB
GPU: 2x Nvidia GTX 480 (configured for SLI)
CPU Cooler: Coolit Eco II (configured as an intake)
PSU: Antec CP-1000
Hard Drive: Western Digital Raptor 150GB
Case: Antec P183 V3

Thermal Testing

To fully load the system, we ran a combination of Prime95 and Furmark until the temperatures stabilized (roughly 10 minutes) with CoreTemp and GPU-Z being used to log the temperatures. This will cause higher temperatures than any normal user is likely to see, but should give us a clear worse-case scenario for cooling. 

We will be testing four different cooling configurations. Twice with the case fans on low and twice with the case fans on medium. For the actual side panel modificaion, we will test with no fan and with a 120mm fan positioned to provide maximum cooling to the video cards, as well as providing a small amount of cooling to the chipset. Since the CPU cooler is getting air directly from outside the case, the CPU temperatures will be largely unaffected by adding a side fan. But since we were getting the data anyways, we went ahead and included it in the charts.

To give a point of comparison, we will also include the temperature readings and thermal images for the Silverstone FT02B-W from the Vertical vs. Horizontal Case Cooling article. The Silverstone FT02B-W is one of the best cooling chassis we have seen, so it will be a good benchmark for us to compare our results against. For ease of visual comparisons, we will rotate the FT02B-W thermal images to match the orientation of the Antec P183 V3 images. We also only have readings for the FT02B-W running fans on the low setting, but we will go ahead and include the readings on both tables.

Low Case Fans No Fan 120mm Fan Silverstone FT02B-W
Idle CPU Temperature 36° C 36° C 28° C
Load CPU Temperature 57° C 58° C 62° C
Idle GPU Temperature 67° C 57° C 46° C
Load GPU Temperature 109° C 97° C 96° C
Idle GPU Fan RPM 1600 RPM 1600 RPM 1660 RPM
Load GPU Fan RPM 5000 RPM 4970 RPM 4450 RPM
Idle Thermal Image   
Load Thermal Image


The temperature logs show a nice 10-12° C drop on the video cards with the side fan added. With just the addition of the one side fan, the load temperatures are already almost equal to our benchmark Silverstone FT02B-W system.

We know from experiance that the fan in this GPU only runs at full speed once it gets past 96° C, which is why both the side fan test and the FT02B-W are both running at that temperature. Since the fan is throttling, we can determine the efficiency of the cooling configuration based on the GPU's fan RPM. Our reading show that while the side fan is able to keep the GPU at its target temperature, it is almost running at 100% fan speed. In comparison, the FT02B-W is only running at about 90% 

Oddly, the CPU idle temperatures are not as good in either test as the Silverstone FT02B-W. This is strange because the CPU cooler is drawing air directly from outside the case in our test system, while in the FT02B-W it is configured as an exhaust. However, under load, the direct intake allows the P183 V3 to have a bit better CPU temperature than the FT02B-W.

The thermal images clearly show the benefits of a side fan, with the hotspots on the motherboard being much smaller when it is included. With the system at load, the white-hot heatsinks on the video cards are replaced with much better looking orange and red readings. The image is close to our benchmark FT02B-W thermal image, but still has a bit to go to match it.

Medium Case Fans No Fan 120mm Fan Silverstone FT02B-W
(Fans on low)
Idle CPU Temperature 36° C 35° C 28° C
Load CPU Temperature 56° C 56° C 62° C
Idle GPU Temperature 62° C 53° C 46° C
Load GPU Temperature 108° C 96° C 96° C
Idle GPU Fan RPM 1610 RPM 1600 RPM 1660 RPM
Load GPU Fan RPM 4990 RPM 4940 RPM 4450 RPM
Idle Thermal Image
Load Thermal Image

With the case fans bumped up to medium, we expected to see a decent drop in GPU temperatures. While we know that this GPU likes to sit around 96° C, the GPU fan speed did not reduce anywhere near what we expected. While we cannot be 100% sure, we believe that this is because the cooling bottleneck is no longer on the amount of fresh air the GPU is getting, but rather simply the limitation of the heatsink. Idle GPU temperatures did however show a 4-6° C drop in temperature, which brings the P183 V3 temperatures a bit closer to the Silverstone FT02B-W temperatures. 

The thermal images show the main cooling advantages of having the case fans running at a higher RPM. At this point, the thermal images on the P183 V3 are even better than the FT02B-W. The fans are running at medium, so the system is certainly no longer quiet, but it is good to see that even this ridiculously hot test system can be cooled to this degree with something as simple as a side fan.


We have known for a while now that side fans can greatly increase system cooling, especially in relation to video cards and chipset. What we have been lacking is this hard data to show exactly how much of a benefit they provide. In the case of our test system, we took one of the hottest desktop systems we could imagine and managed to get the temperatures down to reasonable levels just with the addition of a singe side fan. Doing so clearly shows the potential benefit for having a fan positioned to blow directly over the video card(s).

From an effort/reward perspective, adding a side fan is one of the best things you can do to increase the cooling capability of your chassis. Many chassis today even include mounts for side fans, making the job almost effortless. If you are at all worried about your system running too hot, the addition of a side panel fan should be one of the first things to consider to lower your system temperatures.

Puget Professional Advice
Wilson Chau (Customer Service Manager)Wilson Chau (Customer Service Manager) Says:
Recommended if you have multiple high end video cards in the system and or just want some extra cooling.


wouldn't a better airflowing case do just about the same?

while the p182/3 v1/2 are popular with your builds I don't see anywhere near the popularity of this case in my travels. now that said i like my case but it isn't one that can be stored off the beaten path. in other words it definitely must be placed with airflow in mind if you live in a warmer climate.

Posted on 2011-10-16 00:06:19

Nice article! How about a pc without a gpu? Will it still benefit from side panel fans?

Posted on 2013-11-09 04:16:50

It really depends on what components you have in your system. The last couple generations of motherboards (with the exception of server and some workstation boards) run very, very cool now so a side fan won't help much in most cases. However, when this article was written, motherboards still ran pretty hot so a side fan would help prolong the life of the board. Compare the load thermal image above with a side fan on low: ( http://images.pugetsystems.... ) to one of our current systems with relatively equivelant specs (high-end CPU and SLI video cards, similar cooler, etc): ( https://d2fn9540hpidsu.clou... ).

Besides multiple or hot running video cards, the only other time we strongly encourage side fans on our systems is when a RAID card is being used since they have tiny heatsinks that tend to run really hot.

Posted on 2013-11-11 19:41:57

Hi. I was wondering. If you want positive pressure in your case, you would add a front fan with higher CFM that the exhaust fan. BUT what if you added a lower RPM/CFM fan in the front, and one on the side. Would those two fans RPM'S and CFM's combine to become more pressure than the higher RPM exhaust fan? It seems like they would as each is pulling in its own amount of air to combine with its partner... Does that make sense? Thanks

Posted on 2014-03-30 20:53:07


Posted on 2015-05-08 23:08:49

My problem is with my R9 290's in Crossfire. My bottom gpu is fine. Tops out at 80-82 C. Top GPU gets up to 94 degrees C in GTA V, Witcher 3, Dying Light, Shadow of Mordor etc. But my top gpu sucks in all that hot air rising off bottom gpu. It's scorching hot when I put a hand between the two cards. Touching anything will LITERALLY burn you. It's only 1 slot between them. I've taken out the PCI slot cover from back and helps a LITTLE (like 1 degree C) but it's not enough. I have 3 140mm Fractal Design High air flow front fans in Fractal Design Define S case. (one rear, one top rear 140mm too) So there's NO obstruction in front of case. Hard drives are on other side of case where cables are. They blow 100+ cfm each, especially with dust filter off. And I have a 120mm below bottom gpu pushing cool air right into 2 of the 3 fans. What are some solutions to get some air between those two cards so the top gpu isn't sucking all the hot air rising off bottom gpu? I was thinking of maybe a PCI blower fan mounted from OUTSIDE of case blowing air in but would have to rig it to get it to work. I was also thinking off getting some slits cut at 45 degree downward angle (mostly for looks) in my side window. My last case had 200mm fan on side but no window. It worked like charm. Is that really my best bet? Just modding slits and/or a fan into side of case? I really don't want to do that though as I bought the case to see inside a clean, open inside.

Posted on 2015-06-25 00:41:57

Honestly? Yeah, a side fan is probably your best bet. We usually recommend those when doing dual video cards, unless the video cards are ones that do a really good job of venting their heat out the back of the system (rather than letting it rise and warm the upper card more than it can handle). Further, AMD cards tend to run hotter than NVIDIA cards. I suspect this isn't an option, but if you are within the refund period on the video cards you might send them back and get a pair of GeForce 900-series cards instead. We have done 970s and 980s without side fans and had them cool well, but you have to get versions with blower fans.

Posted on 2015-06-25 06:35:03

Hi. If anyone's still active on this thread, I have 2 Noctua 120mm fans, and was wondering if it would be better to put them on top for exhaust and intake, or keep one on the side panel for the GPU, and keep one up top for exhaust. I just need a hypothetical answer- sorry I can't provide any specifications atm.

Posted on 2017-01-18 08:51:06
Tony Cole

I had issues with sli they ending up overheating I thought originally it was the 4k res. but went to 1080 p 144 hz cooled some but still alittle hot 4 my taste they're 2 gtx 1070s in sli with 4 fans 2 in front 2 in the back but wouldn't it be best to have fans on the side of the case ??

Posted on 2017-03-24 17:02:33

We almost always add a side fan to cases when they will have multiple video cards installed, so yes: adding a side fan to your setup would probably be a good idea. The types of video cards themselves can also make a difference, as we have found that cards which have multiple fans but exhaust heat back into the case do not work well in pairs. Those are fine when just a single card is uses, but for multi-GPU setups we use video cards with rear-exhaust cooling configurations (like the Founders Edition cards from NVIDIA).

Posted on 2017-03-24 17:26:12