Originally Posted by Oscuro
Originally Posted by Nemesis429
Another silly case, everyone seems to be wanting to put the PSU directly above the CPU, when the PSU should be mounted at the front allowing a fairly tall CPU cooler....
Or put the PSU beneath the motherboard like in the Cubitek Mini-Tank. Shorter lengthwise, and taller in height.
I want more people to get into SFF modding so it's time for a write-up!
Let's assume that we want the case to be as small or almost as small as possible.
The longest part in a SFF computer case is the GPU. We're going to use a 6990 for this just because it is the longest card possible.
That leaves two major areas of space to fill.
These two spaces will exist regardless of whether or not something is going there.
Now if we were to add in a PSU to the bottom, we get a whole different space to work with.
So what would logical to add to that space? 3.5" Hard drives!
But now to accomodate the connectors for the drives, it must be made wider (or use a backplane but that complicates things).
Next we have to start adding in cooling for everything. With this design type, we are provided with unlimited vertical CPU height if you just make the case taller. At the exact height it is right now, we are provided with about 140mm of CPU cooler height.
As you can see, this will usually balloon up the size of the case overall. What it does do though, is afford the most flexibility with parts. I personally call this the "ATX mindset". What I mean is that you want the option
to put whatever you want in the case without compromise. This is usually at the cost of space efficiency.
Lian-Li and Silverstone have their own approaches to the SFF market.
Lian-Li wants the best HDD flexibility. That's why they usually have racks for HDDs and a fan properly cooling them. They do this at the cost of CPU cooler space by putting the PSU on top of the mobo. Sometimes, HDD flexibility is also at the cost of GPU length. They are also proponents of air cooling so they use the bare minimum space to fit fans in the case.
Silverstone is more gamer friendly. They sacrifice more HDDs for better cooling and much smaller sizes. Even within their SFF line-up, they take two different approaches.
-The SG05/06 (~11L) approach sacrifices PSU compatibility (using SFX psus) and HDD flexibility. What they get is the smallest case on the mainstream market that houses powerful hardware. Prior to the GTX 690 (which might work anyways), any card that could fit under 10.5" would be fine for the included 450W PSU. Because of this, there was no reason to use a larger PSU. Cooling takes a hit but is better because of the SFX psu. Probably unintentionally, the front was built in a way that allowed for a 120 AIO rad to fit there. This allows for good cooling and enough space for everything that an average gamer would need inside the case.
-The SG07/08 (~14L) approach is a little different. They chose to make the case longer to accommodate the longest GPUs possible. Because of this, they couldn't use an SFX psu and had to upgrade to ATX. They'd either have to take the approach I outlined above, or make the case a bit taller to fit it in the back. This would've massively reduced the amount of space for the CPU cooler. What they did is move it up front. The problem with this is that to fit in in the normal constraints of the mobo, it had to be under 160mm (approx 150mm iirc). This makes it so that there are only two 600W PSUs on the market that will fit. There is the one that comes with the case. The second is the Nexus NX-6000R3
. By moving the PSU to the front, they limited the amount of space for HDDs and figured that the current layout would be the best. The next problem for them to solve is how to cool the HDDs in the front. They can't put a fan there since most of it would be wasted on the side of the PSU. Instead they use a high static pressure AP181 fan to blow air through the whole area.
Fractal Design Node 304 took an approach similar to the SG07/08 approach but decided to make it larger to fit front fanned cooling for the HDDs, space for larger PSUs, and plenty of space for CPU coolers and even AIO coolers. (I consider this one of the best designs released so far).
Coolermaster took the Lian-Li approach and made it into a shoe-box. By reducing the amount of drive slots, they could make it shorter than a Lian-Li. They also extended the PSU out of the back of the case. This allowed them to fit longer PSUs without increasing the overall length of the case.
That ends my lesson on design implications in SFF computing.
I think that they need to move to using PCI-e risers like in the server world but I am sure I am the minority there.
I hope this gave people some ideas for designing a small form factor case. This market is only going to get larger so it is interesting to see what new people coming in can come up with.Edited by armourcore9brker - 6/21/12 at 11:30am