Honest question, in modern times, why are arcade PCB's still so HUGE?

[Quantium]

I've always wondered this, and after searching around the net, I still don't really have an answer.  Doesn't it have to do with how the chips are accessed?  I guess I can't seem to figure out how we have these very powerful tablets and smartphones nowadays, and yet, these simple arcade games (graphically), come on PCB's the size of small briefcases (or atleast used to be).  Shouldn't you just be able to plug in a thumbdrive into the arcade cabinet and play a game? Also, why is the hardware so slow?  The Hitachi SH-3 chip only runs at 133Mhz?  Didn't we pass that speed in processors like back in 1992? Anyone have some good info for me?  Thanks.

[Muchi Muchi Spork]

Which boards are you talking about? The big ones are old ones. If they are new they are probably a PC if they are big. The Cave SH3 boards are tiny. Putting a faster processor on it would have added to their bottom line and it wasn't needed for the type of games they made. Look at the bullet count in Futari God Mode and so on, do we need more than that? Anyway I don't see any point in making a board much smaller than the SH3 Cave boards because it's going to need to plug into a Jamma harness. There's plenty of space for it in an arcade cab. I don't really understand the question.

[Quantium]

Yep, I should've clarified.  After seeing some comparison pictures, I guess I would be referring to like pre-1996 arcade boards, as you said, current Cave boards are very small.  But still, why such abundant use of so many chips?  Shouldn't you need just the CPU, GPU, RAM, and Storage media?  Even Cave boards have like 20 different chips on them.

[Muchi Muchi Spork]

I'm sure it's always mostly to save money, to get what you need done with no wasted cost. There's tons of physical space in an arcade cab, no reason to keep a board small, so if you can get 20 1 meg chips for cheaper than 1 20 meg chip and it will run your game then you go with the cheaper option. Using the latest processor on an arcade game could cut big time into profits depending on the game you are making. For a 2D shooter it's overkill. Also the SH3 at 133 Mhz is a totally different world from an old Pentium 133 running Windows in the background. The SH3 is plenty for a 2D arcade shooter. The way they break stuff up can also help with development ease, pcb repairs, hardware performance, etc., like having some chips be for graphics, some be for program and some for sound so they can run simultaneous jobs, which is why, for example, the sound flow doesn't budge even when Akai Katana Limited goes into slide show mode.

[brentsg]

Let's not forget what these companies' core competency is.  They are software development houses.  They design and have a cost effective PCB reference design..  They are motivated to ride that thing as long as they possibly can.

Also, since Cave has continued to target the same JAMMA system, that's easy.

[Quantium]

Ah. thanks guys.  Good answers.  Are there any websites which have more information about how these boards actually work?  I'm a techy person, so the lingo isn't hard to understand, I'm just curious.

[Muchi Muchi Spork]

Well there's the mame source code for the 90s and PGM games and Progear or the Cave of Shooting links on the arcade games page. It's hard to tell what depth of detail you are after.

[Quantium]

I guess just some general details about how these PCB's function, like what all the chips do, etc.

[Muchi Muchi Spork]

Go here:
http://www.world-of-arcades.net/Cave/cave.htm

Click on a game name then the hardware link, download the high res pic, then google a chip name followed by datasheet. The datasheets tell you everything you could want to know.