Is a ring shaped motherboard possible?

Would a ring shaped motherboard work? For example if you took the chipset of a standard cd-rw drive and rearranged it into a ring shape on a disc shaped motherboard with a hole in the center would if function properly. Or would the shape cause inefficiencies in data movement or other problems?

I see absolutely no reason why it shouldn’t work. It is the connections and not the shape of circutry that matters.

There’s no reason it wouldn’t work but it would pretty stupid from an electrical engineering point of view as the goal is usually to make component to component connections as short as possible for maximum speed and efficiency.

the reason i ask is because of an invention im thinking of developing. like astro said, my concern was that the distance from chip to chip would not be as effecient as on a standard rectangular mobotherboard. is it likely that this could seriously affect performance?

Ring shaped.

Is that a disk, with a circular hole in the center?

You will necessarily have some circuit paths that are longer than they would be without the hole. If you engineer it so that the access times of critical systems are the least affected, and the normally longer processes are the more distant, the difference will be somewhat ameliorated, but will still exist.

Is that a cylinder, with the inner or outer surface containing the circuits?

In that case, no particular loss of efficiency is inevitable, since the surface is topologically similar to a rectangle, but it will only have two edges, instead of four. That may be beneficial, or it may be a difficulty, depending on your input output needs. Cooling is likely to be affected, as well. With a cylindrical heat sink/ground with circuitry on both sides, you may gain advantage from shorter circuit length, if your chip set is designed to maximize the benefits of the shape.

But you are talking about a bottom up custom redesign of a critical technology for a single application. Very expensive.


Rule of Reason: “If nobody uses it, there’s a reason.”

thanks Triskadecamus very useful info.

If you really are talking about a curved (cylindrical) motherboard, I don’t see how it is possible with standard fabrication methods. There are flexible printed circuit boards but I don’t think they have enough layers to work as a motherboard. Anyway, even if you could get a board like that you won’t be able to solder large surface-mount chips, connectors and sockets to it.

A flat circular board with a hole is most likely possible, but it’s not a very efficient way of using the circuit board. You’d have to make a square board first and cut it into shape, wasting the corner and center pieces. In any case, do you realize how expensive it is to get a custom-built motherboard designed and built? I’d guess it would be far cheaper to choose the smallest motherboard available and cram it into the case somehow. Some of the special purpose single-board computers are amazingly small.

      • You’re making a digital hat, aren’t you?
  • Seriously, when a circuit board is assembled, it is pool-soldered. It is placed on an assembly line conveyor belt, the components are inserted properly with their wires sticking through in the little holes of the motherboard, and then the conveyor belt drags the board through/across a pool of molten (liquid) solder. The board floats on the liquid solder, and solder sticks to the wires as the board is removed from the pool, instantly soldering every connection on the bottom side at once. That’s why all the solder is always on one side of a circuit board, every wire has the same amount of solder on it, and all the components stick out on the other side. -Any components fastened to the solder-side have to be done by hand afterwards, so that is avoided if at all possible. That’s also why the solder-side of the board is varnished green; because the solder will stick to any exposed metal but not varnish.
    -If you use a tube-shaped motherboard, you can’t do that, which will boooost your labor and costs considerably. It probably isn’t impossible, but you’d need to have pretty good justification to get VC money for it. - DougC

I work with 'puters. Here is my R0,02c worth.

The biggest problem is efficiency. If you need a fast motherboard, this is going to be a problem.

Electricity travels at around 0.6c (2/3 light) and your board wants to have a bus speed of around 133MHz. If the circuit goes off and on at 133 000 000 times per second, then at some point in the distance of the wire, one side of a circuit will be ‘on’ and another side will be ‘off’. Although this works in larger scales, it cannot work at this level because you will need a computer to monitor and correct signals.

You will have to be certain that all cables in the bus are exactly the same length or there will be chaos at the atomic timing level and for signal clarity, it may be necessary to run the cables at particular distances from each other in particular paths, to cancel out or avoid electrical noise.

On a larger scale, using this logic will help you calculate why there are maximum lengths of network cables and why there are minimum lengths.

A circle would be easy. A ring would be much more difficult. Computers use very high frequency signals, and you can’t drive these signals very far. That’s why you only have 3 PCI slots on most motherboards. If you need more slots, you need a bridge chip and effectively you make a 2nd PCI bus, again with probably no more than 3 slots (if you’ve got 6 PCI slots in your motherboard, take a close look - it’s really 2 busses next to each other).

Trying to arrange the processor, support chips, and the peripheral bus in a ring shape is going to be quite challenging, to say the least. If the hole in the middle is fairly small, then you can pack things in pretty close. Otherwise, there signal traces are just going to end up being way too long.

I’m not saying it’s impossible, but I wouldn’t want to be the guy who’s got to lay it all out and make it work.

How about toroidal? That way, it’s like a rectangle, topologically, except that the opposite edges are brought around to each other and connected, thus the maximum length any signal has to travel is halved. Of course, building it would be a bitch. But perhaps with the core used for liguid nitrogen cooling or something, it could be an interesting design for supercomputer processers.

i had a flat ciricle with a hole in mind. but from sound of it this project might not be doable. cd-rw hardware is flaky enough without going to extremes.

That is not really true any more. Only with through hole parts which are going out of fashion because they are so big. These are parts where the leads go through the mother board. Surface mount parts usually have solder balls or solder paste applied to the leads then they are run through an oven which will melt the balls or paste and that solders the parts to the board. Not that it help the OP much.

When you say ‘motherboard’, it sounds like you mean the main circuit board for a CD drive, rather than a PC mainboard, am I right?
If this is the case, that ought to make it a whole lot more feasible.

thats exactly what i meant Mangetout. why would this change things, though? currently, im under the impression that it would take a great deal of brilliant engineering and mullah to figure out the necessary configuration for a ring shaped mobo of any kind to work… if it could work at all.

If you have to rely on appeals to Allah to make it work it might be trouble than it’s worth.

Mullah = cash, dinero, currency, etc.
Allah = the one God of the Islamic faith.

I make it a point never to confuse the two.

Man, you’ve a special dictionary!

In that case, may Allah bless you with loads of Mullah. :slight_smile:

My impression is that, not withstanding what others have said, it could be done but the cost would be enourmous. There are plenty of companies that do this kind of work for others and you could ask them… although they might blow you away if the see you really do not know what you are talking about… I have several inventions in that stage of development myself.

Mullah = a Muslim religious teacher
moolah or moola = cash, dinero, currency, etc.