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mlord
join:2006-11-05
Kanata, ON

mlord to taytong888

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Re: Upgrading Firmware on DCM-476 modems

said by taytong888:

Today I noticed that a local (Ottawa) online shop sells DCM-475 for about $86 ish, compared to DCM-476 which goes for about $4 less.

Just wondering if this is because the 475 modem will not likely overheat, and disconnect, less often due to a larger heatsink than DCM-476?

That's a thought, but I doubt it. The 476 probably just has a newer generation chip that uses less power. Neither modem is really "better" than the other, though I do prefer the soft green LEDs of the 475 to the garish blue ones on the 476.
mlord

3 edits

mlord

Member

said by mlord:

The 476 probably just has a newer generation chip that uses less power. Neither modem is really "better" than the other, though I do prefer the soft green LEDs of the 475 to the garish blue ones on the 476.

Okay, I've taken a current generation DCM-475 modem and compared power consumption with my August/2012 DCM-476 modem. The DCM-475 actually uses ever so slightly less power than the DCM-476.

This is in "idle" mode, with no cable line connected.
And the difference was small, but consistent.
Slightly less than one watt.

0.044 amps @ 125VAC versus 0.052 amps @ 125VAC.

Edit: I've also now measured consumption on my nearly 3-year old DCM-475 that connects us to the internet here, and it shows pretty much the same number as the brand new DCM-475. Both are about 16% more power efficient than the DCM-476, independent of which PSU is used.

There are also slight differences between PSUs, depending upon which stock the manufacturer happened to have on hand when packaging the individual modems. The variance there seems to be within half a watt.

Cheers
mlord

mlord

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said by mlord:

I've also now measured consumption on my nearly 3-year old DCM-475 that connects us to the internet here, and it shows pretty much the same number as the brand new DCM-475. Both are about 16% more power efficient than the DCM-476, independent of which PSU is used.

Heh.. it's probably due to those blindingly bright blue LEDs on the DCM-476. Perhaps I should swap out the resistors on those for higher values and see if the power consumption takes a measurable drop afterward.

Teddy Boom
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Toronto, ON

Teddy Boom to mlord

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said by mlord:

said by mlord:

The 476 probably just has a newer generation chip that uses less power.

Funny, but ya, it is probably the LEDs. Even though the 476 draws more, that theory is probably still correct, the CPU probably is a little more efficient.

There is also probably a field failure aspect. Once they know there are very few field failures, they can afford to be a little less conservative about the thermal design.