What exactly does the bezel hide?

[satchmo]

I understand the bezel hides the top front facing camera, but what prevents them from being thinner along the sides and bottom? Shielding from radiation?

I seem to recall there was some reason why a black frame was necessary in earlier first generation iMacs. But surely we’ve reached a point where edge-to-edge displays, are possible.

I know all the rumours point to a redesign in 2018, but I’d be happy with the existing design with a 1/2” reduction in black bezel. That would make the iMac feel so much more light and airy.

 

[redheeler]

It's clear Apple could've slimmed the bezels here, but decided to make the edges thin instead. Shrinking of some other parts internally would be needed to achieve both and still have room for the iMac's internal sound system.

Unclear if Apple really has a redesign planned for 2018, as the iMac Pro is still using the existing design (though in a nice Space Gray color), and it's likely Apple would keep the design for another year or two.

That being said, large bezels on a desktop is a non-issue IMHO - on a laptop, you want small size for portability, but on a desktop, it really doesn't matter. Same goes for thick edges, but clearly Apple disagrees.

 

[Gameboy70]

I 27" Retina iMac at peak CPU load hits 819 BTU. You can't have edge-to-edge electronics under the hood.

Thermal constraints aside, engineers will always push for smaller bezels on anything with a screen—desktop or laptop—if for no other reason than consumer demand. The 42" plasma I had 8 years ago can easily fit inside any of today's 50" TVs. There aren't many shoppers who would see two otherwise similar monitors side-by-side in a showroom and choose the one with thicker bezels.

 

[theluggage]

That being said, large bezels on a desktop is a non-issue IMHO - on a laptop, you want small size for portability, but on a desktop, it really doesn't matter.

I'm guessing that the fresh air in the "chin" may also play a role in the acoustics - considering that the iMac speakers are pretty good for a thin device with no speaker grilles. Plus, more aluminium is good for heat dissipation.

Mainly, though, as you say, the tapered edges make it look thinner than it is - cut the bezel and the bulge would have to be "steeper" to get the same thickness in the middle where all the guts are.

Still, I do wonder whether they could have fitted a slightly larger display in the same size box.

and it's likely Apple would keep the design for another year or two.

Probably.
However, my guess is that, whenever the update happens, they'll restrict the regular iMac to the new 65W i5 processors (which now have 6 cores) and no longer having to accommodate the 95W beasts will let them slim down the design significantly. Since the new 65W i5s are faster than the current 95W i7 this doesn't seem like such a bad thing - and there will be the iMac Pro (and maybe a new Mac Pro) for those who need more.

 

[Ph.D.]

The iMac Pro takes advantage of the bulk inside the current iMac chassis for larger heat sinks and fans (plural), etc. It's unlikely that a slimmed-down configuration would be able to handle the heat.

I think it's perfectly reasonable that Apple would allow the iMac Pro to continue in the legacy form-factor, while a redesigned non-pro iMac could adopt a significantly slimmed down design reminiscent of a vertically-mounted laptop form-factor, with minimal bezels. I could imagine that a vestigial chin might remain just for design continuity.

Personally, I'd like to hope that at least one fanless model could be offered. Make it OLED, too, thank you. I'd pay a hefty premium for such a model.

 

[satchmo]

I 27" Retina iMac at peak CPU load hits 819 BTU. You can't have edge-to-edge electronics under the hood.

Thermal constraints aside, engineers will always push for smaller bezels on anything with a screen—desktop or laptop—if for no other reason than consumer demand. The 42" plasma I had 8 years ago can easily fit inside any of today's 50" TVs. There aren't many shoppers who would see two otherwise similar monitors side-by-side in a showroom and choose the one with thicker bezels.

Perhaps not technically edge-to-edge, but I’d love to see a future iMac with bezels like this Dell monitor.
Even if it kept a larger lower chin for branding/guts of computer.