Level 1

0 points

Slow Cable Modems - Everyone Please Read

I am a Broadcom employee. Broadcom makes cable modem chipsets. Some of these chipsets have a slight design flaw. I am not at liberty to divulge any technical details. However, I can tell you that using a cable modem containing one of these chipsets with your Mac will result in slow internet speeds. Apple is not at fault. I'm sorry to say that fixing these design flaws, which only affect Mac users is not a priority at this time.

I am a Mac user myself and am just as frustrated as you are with incompatible products. This is why I am coming forward and informing you of this problem with our products. Our chipsets are used in almost all of the most popular cable modems. I am including a partial list of the most recent and popular cable modems that use our chipsets which have this problem. I am unable to find any information about older and less popular cable modems. Please understand that I can not and will not divulge any more information. Thank you.

All Linksys Cable Modems
All Motorola Cable Modems except for the SB5120
All Scientific Atlanta Cable Modems

Posted on Aug 25, 2006 12:07 PM

62 replies

Sep 17, 2006 5:39 AM in response to Broadcom

Would turning off autonegotiation on the modem and the Mac fix the problem? We have a similar issue with our network at work where using autonegotiation produces poor network throughput. This is not a cable modem thing. Turning off autonegotiation and switching it to whatever the network port should be fixes the problem 100% of the time.

kcoppola

Level 1

0 points

Sep 21, 2006 10:44 AM in response to Karl Wojcik

Oh my God! I had a Motorola 5201 (I think...either way, it was one of the bad ones) and I was getting 200 kps if I was lucky. We purchased a D-Link for about $40. I am now getting 1.8 mps. A bit of an improvement, don't ya think?

Thank you so much for starting this thread.

Kim

Sep 21, 2006 6:39 PM in response to Broadcom

This is very interesting to me.. I too am having the same problem and it is with my mac and not my PC. i hvae an sbv5120 by motorolla.

Any thing I can do about this.

I thought it was my router but I guess it is not.

Sep 21, 2006 7:18 PM in response to tsteph5

I just called my local cable company. The did a check and siad I have an older cable modem and that an upgrade will solve 99% of the problems. They confirmed it is a known issue on the mac.

Sep 22, 2006 6:11 PM in response to sseligson

I got a new cable modem today. This time it is a scientific atlanta. Problem solved. Works fine now. Thanks to everyone for the help.

By the way is there a speed test I can do?

tsteph5

Level 1

45 points

Sep 22, 2006 8:59 PM in response to sseligson

yep. here http://www.speakeasy.net/speedtest/ pick the server closest to you. then i always do one in CA just for ha ha's.

neonsox

Level 2

214 points

Mar 14, 2007 5:41 PM in response to Broadcom

I have a Motorola SB5100 (Surfboard) Modem and speeds are just fine. I have a router set up between my computers though, and everything is hardwired. None of this wireless crap. Speeds are the same on all of my computers (Mac OS, Linux, and Windows XP).

Sep 23, 2006 2:32 AM in response to neonsox

Router question....

First off I am going much faster now then with the motorla modem. The SI webstar solved my problem.

Before a page would load about half way and then stop. Now I have a question about my router.

I have an older linksys router. Probably about 4 years old. It is a wireless router but I connect directly via ethernet port.

A guy at compusa told me if I get a new router I will see increased speeds. Any truth to this?

Sep 23, 2006 2:37 AM in response to sseligson

Are these good speeds?

Download Speed: 7931 kbps (991.4 KB/sec transfer rate)
Upload Speed: 1781 kbps (222.6 KB/sec transfer rate)

Sep 23, 2006 9:58 AM in response to neonsox

Likewise ... I have a Motorola SB5100 provided by Rogers Cable in Canada and I cannot see any problems. We have both hardwired and wireless connections in this household.

neonsox

Level 2

214 points

Sep 25, 2006 11:33 PM in response to sseligson

You might indeed see better speeds because the wireless protocol has been improved over the years. Each model gets a little faster and a little more secure. I suggest comparing specs on your current router and a new one.

For more information on the changes to 802.11 over the years, look at http://en.wikipedia.org/wiki/802.11

Broadcom Author

Level 1

0 points

Sep 26, 2006 12:10 PM in response to neonsox

I'm thinking this post is bogus because I've never
had a problem with this model cable modem on any of
my systems.

I'm glad you haven't had any problems. You can think whatever you want, but the fact remains.

Take your political agenda elsewhere.

I'm sorry, but I don't have one. A Cox employee is informing Mac users about this too. http://www.dslreports.com/forum/remark,16772229

manfer

Level 1

0 points

Oct 4, 2006 11:06 AM in response to Broadcom

Hello Broadcom,

I am having some issues( http://discussions.apple.com/forum.jspa?forumID=755)
with my new iMac and found this post.

I have a NLC RG-2000 residential gateway that I am almost sure uses a Broadcom chip. Is this true? If so, could this be the reason why I am having download problems?

jalfred

Level 1

0 points

Oct 4, 2006 2:49 PM in response to Broadcom

I totally buy into this. I had a Toshiba modem and was getting horribly inconsistent speeds that would drop to zero and stall. These crappy speeds had been going on for years. Was considering a swith to Verizon FiOS. Had Comcast scheduled to come out tomorrow, but found this thread today and went out and bought a Motorola 5120 modem. I am now getting at least 3-4x the speed that I was getting. It is constant with no stalls. Needless to say, I canceled the Comcast housecall.

Getting the same fast speeds with my router (Netgear FVS318v1) that I am direct to modem. So that rules out any thoughts of the router contributing to the problem.

Thanks for creating this thread!

Oct 4, 2006 3:13 PM in response to Broadcom

I got my new cable modem and it was much better but I was still getting a delay. The speed test was fine. But a page would start to load and then just stop in the middle and get stuck.

After speaking with some people it turns out there was no DNS numbers in my network settings. I added the DNS #'s and I am flying so fast right now!!!!

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Slow Cable Modems - Everyone Please Read