[Concept] "Bento"/"Bian Dang"

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Alright, the start of project "Bento" or "Bian Dang" (both are basically the same, one being Japanese and the other Chinese). The idea is to make the smallest, most space efficient setup for something that runs off a PicoPSU, although I already have one involving a SFX and/or ATX PSU in mind (probably SFX because ATX...meh. We have 600W-650W SFX 80 Plus Gold PSUs already so small and efficient). My minimalist nature makes me want to avoid using PCIe x16 extension cables/riser cables BUT if I did that I would just end up with an NCASE M1 clone (go check it out. Beautiful case). Originally I was thinking about going with a layout like the Silverstone RVZ01/ML07/etc. but that layout becomes space inefficient as you get PCIe cards longer than the mITX motherboard.

Anyways, a quick mockup using a PCIe x16 card at the PCIe x1 Half Length spec (around 170mm). For reference, I've thrown in two 2.5" HDD/SSDs. The top one is 15mm tall and the bottom one is your normal 9.5mm tall drive.






Okay, so first problem with this layout (that I don't intend to fix) - you cannot fit a 3.5" HDD. That's not really the point of this built. This is supposed to be a light build, so SSDs are the go to, or 2.5" HDDs if you want. If you want a 3.5" HDD go get a NCASE M1 or another case. There are plenty of small enough cases out there that can hold 3.5" drives.

As for the construction I'm going to do something like the Murderbox MKII where I use a 8mm thick or so motherboard tray. I want to do this because I can get the midplate CNCed to get some modular attachments on it such as a HDD cage or to hide longer PCIe extension cables (its thick enough so you could hollow out a thin compartment in the middle to fold the cable over itself).

As for powered vs unpowered PCIe x16 extension cables/riser cards, PCIe x16 slots support up to 75W of power from the connector itself and the 750 Ti doesn't hit that limit (its 10W+ below stock).

I'm thinking about making a single slot version because 1. Galaxy GTX 750 Ti Razor Edition and 2. for those who want to put in smaller, weaker cards. Is it really worth it? Probably not. I think just a short version (PicoPSU based) and a longer version (SFX based) is good enough.

Next big dilemma to get over is maximum CPU cooler height. By mITX specification I need to allow 58mm over the motherboard around the general CPU area socket in order for it to fall into specification (not that motherboard manufacturers usually put in anything that tall on their mobos). Top-down coolers are in sort of a weird spot. You have coolers like the Cryorig C1 and Thermalright AXP-200 which are 60mm tall, 85mm with a fan and then there's the Noctua NH-L12 which is 66mm tall without a top fan (91mm with fan) and then a pretty big gap until you arrive at the NH-C14 and then the Phanteks PH-TC14CS which are both above 100mm tall since they're basically copies of their dual-tower monsters except with one tower and turned into a top-down.

By the way, the most powerful card that can fit into that mockup is the MSi GTX 760 ITX Edition which is around 170mm long but requires an 8-pin power connector. I don't know if I should leave space for people so they can drill in holes for standoffs for PicoPSUs like the HDPlex 250W DC-ATX PSU or the Pico-Box X3-ATX-300. Pico-Box includes a PSU mounting kit that matches up to the normal 86x150mm profile of ATX PSUs but that adds 86mm in length to the entire case which is way too much for my liking. Also, with a 400W peak PSU (400W is the peak for DC-ATX/DC-DC boards because external power bricks only go up to 400W peak as far as I remember. These boards also have a 400W peak) you can power basically any single-card GPU or most (more powerful ones at least) which gives the need to extend the length of the case even more. The short version of this case (PicoPSU based) isn't designed for that purpose but rather for low powered rigs instead.

Also, check out project A4 which is extremely similar (his case is set up a bit differently and is more focused on putting in more powerful graphics cards. Amazing case, go check it out).

And check out the NCASE M1 for being my inspiration to look at SFF PCs.
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Hm...starting to rethink the design. I originally sought after something like the S3 Mini (link, internal layout is on the page before) but that kind of gives you a really awkward footprint for the case if its laying down flat. It would end up around 300 mm wide and around 180-200 mm deep (it depends on how much tolerance I want to give). Still pretty damn small though.

As for height, if I want to keep the case within mITX spec I need to allow 58mm over the CPU area so I would end up with 58mm + 1.5875mm (1/16", standard PCB thickness) + 12.7mm (1/4" standoffs, which has a 1/4" standoff female end and a 1/4" male end adding up to a 1/2" long standoff) = around 72.2875 mm tall or around 2.85" which is already much taller than the S3, even more so the S3 mini. This ends up with a final volume of around 3.9L.

Should I want to ignore that 58mm clearance for maximum ITX component height (it really only matters for embedded motherboards like the ones that come with an Atom or E-350 APU) but still compliant in every other way I can whittle it down to around 2.2" (about 56mm) which is much nicer in size. Using this would give me 3.024L.

Current mockup dimensions with the same amount of tolerance at the 24-pin side of the mobo (10mm) would give me 200 x 180 x 105 mm (a little more than the minimum of 4.1125") which gives me a volume of 3.78L, which puts me close to the volume of the mITX and ATX spec case.

So, any advantage of that design? Well there's really only 2; the ability to store more 2.5" hard drives and a smaller footprint if sitting down flat like a DVD/Blu-Ray player.

Okay, so next up, volume comparisons with a SFX PSU! (63.5mm tall, 125mm wide, 100-130mm long for SFX and SFX-L). I'm picking SFX over ATX because of the fact that 1. SFX is more space efficient, 2. they already have good performing units, 3. not ridiculously tall.

So, for the mITX and ATX compliant case (layout is like the S3), we end up with the same height and length is increased by 125mm. Final volume becomes 6.62L.

For the compliant in every way except maximum component height + a SFX PSU, we have to increase the height to accomodate the SFX PSU so new height is 63mm, final volume is 5.7645L.

And for the current design of "Bento" we end up with an increased length of 125mm, height in the upper compartment goes from 2.2"/55.88mm to 62.5mm~63mm. So we add 7mm in height at most. New dimensions are 200mm x 305mm x 112mm which gives us a volume of 6.832L.

So really I have no choice but to go for a layout like the S3/S3 or Silverstone RVZ01/ML07 Mini if I want more space efficiency but I don't want to make a clone here so I'm quite torn (although I don't think the guy who designed the S3 mini is making any more as of now).

Small spreadsheet for volume comparison: https://docs.google.com/spreadsheets/d/1YUcHLe4I_hgt6RBMlAPj_SsEtz8WX9z3CAmepvWy8eI/edit?usp=sharing

Edit: if this does become a S3 Mini "clone" really the main difference would be the fact that you do not need to go make your own back plate because I intend to make this ATX/ITX compliant in every way except maximum component height over area A (area covering CPU socket. It doesn't include the PCIe, RAM, and Rear I/O connector areas) of the mITX spec sheet (free to find online @ formfactors.org).
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cant see the design.. images dont load for me :(
but if this is based on s3 mini ... you areon the right track lol
cant see the design.. images dont load for me :(
but if this is based on s3 mini ... you areon the right track lol

album: http://imgur.com/a/VAUDf#0

The original design was based off of the Gigabyte BRIX and Alienware Alpha since that was the only layout I saw that could fit in something that small.

Is the guy making them anymore? I know he had to go through a local company so he's probably making them in batches but I don't know if the demand for it was high enough. If he isn't I'd be happy to try to push this project through (keep in mind I'm only a high school student though).

Anyways, my current question is whether or not:

1. use a PCIe x16 ribbon cable extender so that the GPU intake fan faces the same direction as the CPU heatsink (how the S3 and S3 mini are) or,
2. use a PCIe x16 riser card so the GPU intake is pulling in air from the other side of the case (RVZ01, FTZ01, ML07, ML08 styled).

I was thinking going for something like the S3/S3 Mini. This makes it so you get a huge blank slate on what is the bottom of the S3 and S3 Mini so you can flip the entire case upside down for a nice, clean look. No big disadvantages as far as I can tell. Going with the layout Silverstone has doesn't really have any disadvantages either.

Its really if you want an entire side of the case being ventilated versus having both sides ventilated. If you have this unit sitting horizontally with the ventilation sitting upwards I would just be worried about spilling something onto it, not that you can't do the same with the layout Silverstone has and still damage everything but at least with Silverstone's design you'll only hit the GPU or Mobo, not both (you'd have to spill it at quite an odd angle for that to happen).
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To give you an idea of what I want the final product to look like, here are the closest thing I can find to resemble what I want: the Midi Fighter Twister and Spectra.


Of course, there's no reason to do what you might see as a copy and paste rip for no reason. The design actually works extremely well.

First off, when holding the unit by itself you will probably be holding it like a book, in that your palm and the space between your thumb and other fingers is on the thin side height wise. Making the corners curved makes the corners nicer to hold.

As for the angled edges on the edges of the top and bottom they make it easier to pick up the case whichever side its on. Going for a rounded cube doesn't work very well since half-circle edges are much harder to pick up than just having a 45 degree cut.

Besides, this type of design is used on phones pretty often. If you look at the Nexus 5 or the iPhone 5S you can probably see the rounded corners, angled edges around the side of the phones to make it nicer to hold or use.

The end result is a nice blend of curves and straight edges. Going for a regular box looks quite boring and having 90 degree angled edges looks a little too aggressive IMO. This is meant to be somewhat adorable looking. I want to follow Dieter Rams' "Ten Principles of Design" too. Read about it here: http://startupsthisishowdesignworks.com/ (section 1.3)

So I already explained the curved corners and angled edges for making the product useful, and as far as aesthetic goes it isn't too aggressive or bland by going with 90 degree angles but it doesn't look too much like a "toy" by having all rounded corners in a style like a rounded cube. Nothing fancy going on so its a pretty unobstrusive and minimalist design.

It holds honesty by not making the computer seem more powerful than it really is. If anything, the size and appearance is an understatement to the power you can potentially put in something this small.

Made out of aluminum so long lasting and environmentally friendly. Also, the design is relatively minimal so it will still look good in quite a few years.

And as little design as possible! Quite the simple looking box. I don't think anybody will question it much while they use it.

Ideally the frame will be a unibody, constructed in a way like the TJ07.
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Very basic drawings. You can ignore the SFX and SFX-L PSU drawn to the bottom right. I could try to make a case like that but Silverstone already has 4 cases like that (RVZ01, FTZ01, ML07 and ML08). Skip to the last paragraph to see why I kind of don't want to make a SFX based unit.

Still pondering over what variations should be made. I'm a bit tempted to allow for a few other PicoPSUs like the HDPLEX Hi-Fi 250W (400W peak) unit because a few cards like the R7 265, 260X, etc. need a 6 or 8-pin connector (the GTX760 ITX Edition from MSi requires an 8-pin as far as I know).

Why I'm hesitant to make a SFX based unit

1. Silverstone has 4 units based on that layout
2. Increased height: SFX PSUs are currently taller than the entire case (I'm going to ignore the maximum component height in the mITX spec sheet)
3. Extremely disproportionate performance between the GPU and CPU: see below.

I'm hoping to design this so it is as "thin" as possible. If you go to the MicroATX specification sheet (or ATX) and look at the rear I/O shield requirements you'll see at the very minimum you get 1.7" or 43.18 mm of clearance so long as you do not follow the maximum component height of 58mm over Area A in the mITX addendum to mATX/spec sheet. This limits you to stock coolers, some very low profile coolers that basically perform the same as stock coolers, and maybe one or two low-profile coolers capable of handling a max TDP of 65-80W (the Scythe Kozuti is rated for 95W but from the size and mass it probably handles less. Its probably only slightly better than the Noctua NH-L9a/i which are only rated for 65W). These coolers are only able to handle i3 parts and low wattage i5 parts. Throwing in a SFX PSU lengthens the case to support the most powerful of GPUs (I think the 770 to Titan Black cards all have a PCB length of 10.5" which is around 267mm long cards while just the 170mm side of a mITX board/mDTX board and the 125mm width of a SFX PSU adds up to 295mm).

Even with a SFX PSU maximum height is only increased by 7mm which only allows for 50mm tall coolers.

As far as the top-down cooler scene goes, sub 40-50mm coolers (by the way all of these heights are with their stock fans) are plentiful (too many of those basically stock performance solutions with the exception of the 2-3 above I talked about, if not only a few more), then its pretty empty until you hit 58-74mm with stock fans (Thermalright AXP-100 @ 58, Cryorig C1 and Thermalright AXP-200 clock in at 73-74mm with their thin fans, NH-L12 @ 66mm without the top 120mm fan), and then you get to the 90-100mm+ tall coolers like the NH-C14 or Phantek's offering. At 100mm+ though, this layout would no long retain its efficiency and instead you should be looking at the NCASE M1 because PCIe cards are 111.15mm tall. You'd be better off not using a ribbon cable or riser card and just plug the GPU directly into the x16 slot to save space.

So this is where we arrive at our problem: there are no sub 50mm tall heatsinks (as far as I know) that have the ability to handle a standard wattage i5 or i7 part or at least aren't recommended to do so (I have seen a review of the NH-L9i on a 4770K and it reached 90 on load, although I believe it was throttling itself by then).

So just to quickly summarize here, adding in support for a higher wattage PicoPSU or even extending the case to support SFX would allow for GPUs way more powerful than you should be pairing with an i3. Even a 760 is probably overkill with an i3. This will restrict you to cards like the 750 Ti and lower which do not require a 6 or 8-pin connector in addition to the power provided by a PCIe x16 slot.

Also, feel free to post any recommendations. At this point I'm just using this thread as a journal to write down all of my thoughts on the limits of this case.

Edit: Did some napkin math to see how tall the case would have to be to match the NCASE M1 in volume while still holding a full-length card.

12.6L x 1000 = 12600cm^3
12600/30/31.2 (312mm is the maximum PCIe card length according to the 2.0 electromechanical spec, I don't know about the 3.0 revision)
= 13.46cm (134.6mm), so that's a pretty tall heatsink (that said NCASE only recommends 130 max)

However, the M1 has several stuff this does not have support for (miniDTX, ATX PSU, slim 240mm radiator, 3 expansion slots) so I'll come up with the approximate dimensions of the M1 if it still supported a full length GPU but only a SFX PSU instead of ATX and only 2 slots instead of 3 for GPUs.

Edit2: So we end up with 221.58mm in height (subtract 18.42mm since thats the width of the general part of a PCIe/PCI I/O bracket), 145mm wide (PCIe cards are about 130mm tall with bracket and card combined, 15mm or so extra added to account for motherboard standoffs and power connectors for GPUs), 322.5mm long (5.5 shaved off since PCIe spec allows 312mm cards, M1 allows for 317.5mm cards). Volume now drops down to 10.36L.

So going with this number, the maximum cooler height this style of case can go up with a SFX PSU and full length card is 110.7mm tall.

Okay, so not too bad, but keep in mind this is a M1 comparison. You could probably go even smaller than the M1. Time for more math. So very basic dimensions.

170x170mm for ITX boards, 312mm x 126-ish mm for a full length full height PCIe card, 125mm x 63.5mm x 100-130mm for SFX PSUs (no issue here since it'll fit regardless). Minimum dimensions will lie around 7.963" (202.26mm) x 130mm x 312mm which gives you 8.2L. This case can probably support around 120mm tall heatsinks w/ fan.

So, back to our current RVZ01/FTZ01/ML07/ML08/S3/S3 Mini/Bento design, that means we can have a maximum of 87.6mm case height before the "normal" design w/ SFX PSU becomes of the same volume. Issue here now is that this flat/laid out design is now less space efficient because it cannot support a larger heatsink to cool off a more power hungry CPU. I don't have any wattages so lets use a different system of comparing efficiency: height of heatsink per liter of the case.

So, this "reference" SFX design that I just made up can do 120mm per 8.2L, or 14.6mm per 1L.

Back to the flat design, which does 80mm max height heatsink w/ fan (the 7.6 was shaved off to account for motherboard standoffs and such) will do 9.76mm per 1L. Quite a big difference. What determines this number? Overall case length, which in turn is maximum length GPU supported. I can't think of a way immediately to calculate it so I'll be doing some guess and check at different heatsink heights to get a good idea of how it scales with GPU length. Btw case height will have 15mm added to heatsink height to account for motherboard standoffs (0.25" is the minimum for ATX/ITX boards) and motherboard thickness (1/16" for PCBs, total is about 8mm for mobo + standoffs), along with a elevated CPU socket (I used 7 arbitrarily just to reach a nice number).

Edit: https://docs.google.com/spreadsheets/d/15OiRi7eLJNOAg_cftWPfEWqLHLt2tKIslIGchAylQ_A/edit?usp=sharing

I cover 312 (max), 170 (min and half/length), then I do a few increments in between. Ultimately it comes down to the question of "how tall of a heatsink do you want to support in this case?"

And if we go buy Anandtech's current June 2014 GPU guide we see that the largest GPUs that fit at certain case sizes matches nicely.
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Update: Made a no PCIe device version because I'm not exactly sure how I want the sizing to play out yet with a GPU. Its mostly done. Still need to add some parts. Enjoy!

Forgot to come here and do a few updates. I've changed the aesthetic quite a bit. We're moving more towards a Dieter Rams styled approach. I've abandoned mITX in favor of thin mITX because a 50cm tall case didn't make me too happy as far as size went. Going with thin mITX allows me to go around 35mm (30-40mm). Quick renders using Maxwell for Sketchup:


Dimensions are 195 x 195 x 36 mm. I can make it slightly smaller because in that model I kept a 1 cm clearance from the edges of the thin mITX board (not sure if necessary but it just makes it a bit more pleasant to work with, like putting in or taking out the motherboard). Curve radius if 4mm, aluminum is 2mm thick while its 1.2mm thick around the I/O cutout so it falls within ATX spec (1.2mm falls into the range to which I/O shields can be clipped on). I need to add ventilation on the bottom (possibly a little bit on the sides) and a power button which will be styled like this:


I'm hoping to find a push switch with the nice 5+ mm travel and click like the power buttons on some old DVD players of VCRs.

The only other thing I forgot to update was deciding the curve radius for the corners of the case. Here were some models. From left to right, we have 10mm, 5mm, 4mm, and 2mm. 2mm looks a bit too sharp to me while 10-4mm was good. 4-5mm seemed like the sweet spot. I kind of liked the look of 4mm since the curve radius on my Filco Majestouch 2 Ninja is 4mm in radius.




I don't feel like curves should be so big like on the Mac Mini or some other products. I think a curve radius as large as that becomes distracting and starts drawing attention towards it. These videos should help try to explain why I'm somewhat against corners that are too rounded:


The later half of the ASAP Science video with the car example should help somewhat explain what I'm thinking. The hammer example in the VSauce video also helps. This doesn't apply to circles IMO (ex. circle mesh which obviously isn't cute nor attention grabbing, so long that it isn't a bright color).

So looking at the Mac Mini, the curve radius on it is large enough that it becomes distracting. It starts attracting attention due to its unusually curvy shape.

Although curves may make something look more cute or more attention drawing, going too sharp or angles makes the object too defining. It also begins to stand out like a rounded square with a curve radius that's too large at each corner.

So that makes the middle ground quite obvious: a rounded square with a small curve radius at each corner. For me, 10 mm seems to be stretching it (and you don't really see it on most of Dieter Rams' work either, one of the exceptions being the outer curve radius of the Audio 308 or regie 308).


The inner radius seems to be within that sub 10mm curve radius range though.

With thin mITX dual slot PCIe add-in cards are out of the question (The width would be around 40mm which is 5mm above case height. I would have to add another 1cm to case height). I'm thinking about doing a low profile and full height version. It should be able to accept GPUs that take up 1.5 slots or so. Now I just need to hope that somebody will start making thin mITX boards again with a PCIe x16 slot (gigabyte had one for H61 a few years back) so it can support 75W GPUs without the need of a powered x4 to x16 ribbon cable.
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