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Trillionare

join:2003-04-13
Bel Air, MD

[Connectivity] Motorola 5100 vs. 5120

Recently i decided to buy a cable modem and looking aroud i found a Motorola 5100 and a 5120 is there any diffrence between them, they are both the same price, which one should i get?



lilhurricane
Crunchin' For Cures
Premium,Mod
join:2003-01-11
Purple Zone
kudos:57

1 recommendation

»Comcast High Speed Internet FAQ »What are the differences between the Motorola SB5100, SB5101 & SB5120?


Trillionare

join:2003-04-13
Bel Air, MD

thanks



eatnaders

join:2005-04-07
Mount Laurel, NJ
kudos:1
reply to Trillionare

One is a Broadcom Chipset (SB5100) and the other is a Texas Instruments Chipset (SB5120). Motorola builds 2 vendor chipsets in case one vendor has manufacturing problems.



MadMANN3
Premium
join:2005-08-19
kudos:2

The 5120 is more sensitive to "noise" than the 5100.



Nerdtalker
Working Hard, Or Hardly Working?
Premium,MVM
join:2003-02-18
Tucson, AZ
reply to Trillionare

SB5100
• Has some upstream issues in ex-attbi areas, possibly firmware related
• Broadcom chipset handles noise better, and is thus hardier in 256QAM environments

SB5120
• Doesn't have the same upstream issues the SB5100 has (as far as I know)
• TI (Texas Instruments) chipset is more susceptible to noise related issues, especially in a 256QAM modulated plant
--
"Some people never see the light till it shines thru bullet holes." -Bruce Cockburn

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rseiler

join:2001-11-01

said by Nerdtalker:

SB5100
• TI (Texas Instruments) chipset is more susceptible to noise related issues, especially in a 256QAM modulated plant
Could you expound on that? Noise from what? Is there something I should be keeping it away from? And what's a "modulated plant"?

Incidentally, I note that I have firmware "SB5120-2.9.2.10-SCM03-NOSH," and I've seen references to it going back to last year. If it's still current, I guess they don't update it very often.


Nerdtalker
Working Hard, Or Hardly Working?
Premium,MVM
join:2003-02-18
Tucson, AZ

said by rseiler:

Could you expound on that? Noise from what? Is there something I should be keeping it away from? And what's a "modulated plant"?
Noise as in low SNR (Signal to Noise Ratio). It just isn't as good at handling excessive noise (below 33dB) when the downstream channel is using 256QAM for modulation as the SB5100's broadcom chipset is.

Plant is just a term for cable system.
--
"Some people never see the light till it shines thru bullet holes." -Bruce Cockburn

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rseiler

join:2001-11-01
reply to Trillionare

Ah, OK. I see that mine with the Motorola is 34dB, when it was always between 36dB and 37dB with my old RCA. I always thought it could float down to 30 or so before problems cropped up, but 33 is cutting it close.