The 4L case: The future of gaming PCs or too much compromise required?

I have noticed a few people expressing a desire for a sub 4L case that allows for a short dual slot graphics card and miniITX motherboard, so I figured I would start this thread as a place for people to talk about it without feeling bad about hijacking some other thread.

There have been a couple cases that I know of already that have fit this description. The Hutzy, which unfortunately never came to be, and the CustomMOD flex mini.

I have the CustomMOD case and have done quite a bit of testing in it lately to test the limits of what can be put in it. I’ll post more about this testing later.

Another case I stumbled upon recently is the zs-a4m. So far I have only seen it on Taobao, but it appears to be almost the same design as the Hutzy, with a couple of differences. The motherboard and graphics card are upside down, but more importantly, there is a little space for a couple of slim fans at the top.

 

When I got my CustomMOD flex mini case, I just filled it with some left over parts and a GTX 1050. The version I got was from the 2nd or 3rd batch and I believe it is just under 4L, with almost exactly the same dimensions as the Hutzy ca design. It has been working very well as an HTPC, but the power supply is annoyingly loud when playing games.

Recently I got a GTX 1080 from an Aorus gaming box. It is unique because it comes with a 130mm fan and no shroud.

I got the card for my main system in anticipation of switching from an Ncase M1 to the CCD MI-6, but It has not been getting enough fresh air in the Ncase, and it has been thermally throttling. I was worried that this card didn’t have a good enough cooler so I decided to try to put it in my little CustomMOD flex mini and run some tests without the side panels on to mimic an open air test bench.

Getting this new gpu into the case was very difficult. I had to take the PCI bracket off of the graphics card in order to get it in to the case. I also had to unscrew the PCI slot from the case so that I could get the card in the case and slotted in, then I was able to re-attach the PCI extender cable’s PCI slot to the case. Currently the card is just floating without anything supporting it other than the PCI slot itself. I just don’t have the words to describe how tight of a fit this card is. There were a couple of times that I thought that I just wouldn’t be able to do it.

The flex ATX power supply I have is only a 220W power supply, so I hooked up an SFX power supply that I had laying around and just let it sit outside the case.



Running tests like this resulted in no thermal throttling, and it was very quiet.

I used to think that this setup would be the ultimate SFF system if I just upgraded the flex ATX power supply so it could all fit inside the case.

So I put the side and top/front panels on and ran some tests.



Running tests like this resulted in lots of thermal throttling and lots of fan noise.

Taking the top/front panel off and running the tests again resulted in very little or no throttling.

The “tests” I have been running is just playing World of Warcraft for a few hours. Because that is my main use case for computers that causes any sort of stress to the system, I just stick with that and don’t bother with benchmarks very much.

I was very excited the first time I saw this type of case design, where the GPU fan and the CPU cooler fans just pull in fresh air from the outside causing positive pressure to force the hot air out.

At least that’s how it is supposed to work in theory, but with my experimentation here, it seems that there is too much resistance to the hot air that is trying to get out, and so instead of sucking in fresh air, the fan just re-circulated the hot air inside the case.

So I figure there are a few ways to solve the problem here.

1. Maybe creating some ducting around the fan could stop the recirculation of the hot air. This could be very tricky and the tighter the tolerances, the better I think it will work. I think I’m going to try and do this with some weather stripping.

2. Adding bigger ventilation holes on the top and the front could possibly reduce the pressure and allow the fan to bring in air from the outside. This could be done if I felt like cutting up the case. (The zs-a4m already does this)

3. Adding some exhaust fans to the design could remove the hot air, reduce pressure, and allow the GPU fan to bring in fresh air. (The zs-a4m does this.)

I have become very interested in the zs-a4 because it already has implemented 2 of the 3 mitigation strategies I think will help the most. I have a similar case made by the same guy (the zs-a4) and the quality is really good. Also, it can come completely apart, so it’s easier to fit things in it.

Concerning the fan noise issue with the side panel on:
I think the ventilation pattern on the side panel has a big effect on the fan noise. I probably should have chosen the vent pattern with the bigger holes for a higher %open area.

 

I didn’t like the vent holes on the front of the zs-a4m the first time I saw it, but after my experience with the CustomMOD flex mini, I think that vent holes on the front are necessary. I know that the clean front panel look is popular and I like it myself, but in such a confined case, you just have to have the extra ventilation.

But maybe I’ll change my mind on this after I rig up a fan duct for the GPU......

 

So I went and looked up the specs for my CustomMOD flex mini. I got the 2nd version

CASE FLEX mini 4.1L rev.2
Specs:
- Volume: 3.99L (220mm x 181.5mm x 103mm)
- GPU: length <175mm, height <132mm (Giga 1070 Mini and MSI 1070 Aero ITX compatible)
- CPU Cooler: up to 39mm (Noctua L9i recommended)
- RAM: up to 42 mm

The volume calculation doesn’t take in to account that it isn’t a perfect rectangular prism, so by subtracting the volume of the chamfered top front and back and bottom front edges, it will probably be just under 4L

I ended up making a duct for my graphics card fan and it still throttles about half the time of the top and front panels are on.
It seems that the ventilation pattern needs to be increased to a greater %open pattern in order for this case to be able to handle the GTX1080

As far as throwing it into a bag to take it places: I have done that quite a bit and it works so well. It is such a great traveler.