Mac internet speed slow, PC fast?

Question

Level 1

4 points

Mac internet speed slow, PC fast?

Here's the situation. I have:

-Toshiba CX3200 Cable Modem (ISP is Hyperband)
-Belkin 802.11b router
-Powerbook G4, 1.67Ghz, 1GB RAM
-Custom AMD Desktop, 2.4 Ghz Dual Core
-PowerMac G5 Quad Core, 2GB RAM
-random other machines lying around

This is the problem- my internet connection one day decided to be mean to any computer I have running OSX (possibly due to a recent Apple software update; no firmware has been changed for the router or the modem). My PC's run fine at 1.5 Mbps, the advertised bandwidth I pay for thru Hyperband. My OSX machines, however, crawl and an ugly 146 Kbps.

What's weirder is that I've tested a theory about OSX's differences in TCP, UDP, and TMU values as compared to Windows- I can even run Virtual PC on both my Powerbook and G5 and get the advertised 1.5 Mbps, and as soon as I try anything OSX-side, the speed is the same slow 148 Kbps. Naturally then I tried to tweak network settings, using everything from the Preferences Network panel to dozens of downloads like IPNetTunerX, which either did one or all of the following things:

-NOTHING
-caused a kernel panic, in which I had to reboot with disk first aid or single-user mode
-DECREASED my downstream

I've also tried to directly connect the Powerbook and PowerMac to my modem and see if things got any better- same slowness. Even weirder, I directly connected my PC to the modem, and got NO CONNECTION AT ALL.

As I've said previously, when I first got this broadband service, I had no problems connecting at max speed, be it via Airport or ethernet. Now in the past three weeks I'm lucky to get anything above 56k no matter which port I use on any Mac I have. PC's work fine both wirelessly and wired.

Every now and again though, when I either take all the ports out of my router and just leave the WLAN running, or when I reset my modem, I get decent speed on my Macs- for about an hour or so. Then it goes back to slowness. It also randomly increases speed every so often.

I really want to get to the bottom of this. What's the deal with the slow speed? My machines definitely aren't the bottleneck here if they can do 1.5 Mbps in Virtual PC, but not in any other OSX application.

Has Apple made an update that will require me to update my firmware (if there is such a thing for it yet)? Or am I just screwed?

I've seen similar problems with people complaining about Motorolla Cable Modems over at MacFixIt, but none of the workarounds they have listed have worked for me in any fashion. I need one of the genius dudes from the Apple Store, ASAP!

Powerbook G4, PowerMac G5, Mac OS X (10.4.7), Windows XP SP 2 on other machines

Posted on Aug 10, 2006 5:20 PM

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Answer 1

Faisel

Level 1

25 points

Aug 10, 2006 5:36 PM in response to Shadow Fox

Hi Shadow Fox!

Welcome to Apple Discussions

In order for me to help you let me just try to understand what your problem is: I think your saying:

1. You have an Internet Connection (ISP) at 1.5Mbps
2. Your getting an average of 150Kbps when you download?

If 2. is your problem then I just want to let you know that:

A megabit per second (Mbps or Mbit/s) is a unit of data transfer rate equal to 1,000,000 bits per second or 1,000 kilobits per second.

That means theoretically when you have 1.5Mbps your only at most going to get between 130-150Kbps when you download.

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Answer 2

Kappy

Level 10

361,741 points

Aug 10, 2006 5:40 PM in response to Shadow Fox

Two things: Try using TinkerTool System to reset the network preferences to the Optimized for Broadband. Find out from your ISP if they are using a different MTU than normal. OS X network preferences are configured by default to use automatic MTU detection. However, some ISPs use a different MTU that causes the throughput to slow down considerably. Use the Ethernet tab of the Built-in Ethernet configuration panel to change the MTU if that's necessary.

You might also use the Network Utility (Utilities folder) to check your ISP/system latency. If it's high you might try Apple's Broadband Tuner (www.apple.com/support/downloads/) that is intended to improve network performance on systems with high latency, e.g., satellite.

Last thing to consider is a different router. Some just don't work well with Macs. I'm using a D-Link 524 Wireless 4-port router mated to a Motorola 5100 cable modem and I get full speed performance using Tiger both wired and wireless.

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Answer 3

Shadow Fox Author

Level 1

4 points

Aug 10, 2006 6:10 PM in response to Kappy

Falsel, no noob here- I'm talking about my actual downstream on the test pages of several utility sites (download.com, speakeasy, my ISP's, etc).

On those sites, the results are this:

PC: 1.5 Mbps (or around 100KB+ down; BYTE and not BIT)
Mac: 146 Kbps (or around 4-6KB down)

The latter of the two speeds is downright atrocious.

Kappy, I have one issue to bring up- I've NEVER had an issue with my router before I moved here and switched to this new ISP and modem. Before I used a Bellsouth Speedstream modem at my parent's house and my last apartment with the same router (it's been ticking along fine all these years with considerable throughput at 3-6 Mbps and 10 Mbps test DSL right before I moved out 4 months ago).

Here, I was fine using the new modem for about 3 months, and then just weeks ago my bandwidth went down the crapper on all my macs.

BTW, I used TinkerTool, and it's "Make Permanent" feature caused me to have to reload OSX due to an infinite loop of a kernel panic at startup via Airport. I think I'll stick to playing around with the preferences panel some more; you've mentioned some things I haven't tried yet.

What I want to know is WHY all of a sudden this happens? I know it's something going on with OSX, I just can't pinpoint it precisely...

Thank you for the replies.

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Answer 4

Kappy

Level 10

361,741 points

Aug 10, 2006 6:24 PM in response to Shadow Fox

I would think about reinstalling OS X. TinkerTool System's changes would not cause any such problem as you describe, which suggests you may have more serious system problems.

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Answer 5

mahippos

Level 3

896 points

Aug 10, 2006 6:36 PM in response to Shadow Fox

It sounds like a nasty problem. I can give you only a tiny answer, which is irrelevant to your main concern. Switching computers directly connected to your broadband modem sometimes fails to work because your ISP is trying to communicate with a previous computer. If you wait long enough for the DHCP lease to expire, the new computer will get connected.

As for your main concern, have you tried testing data transfer rates between different computers on your LAN. This could help isolate the issue to Mac OS X or your broadband provider. Good luck.

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Answer 6

Faisel

Level 1

25 points

Aug 10, 2006 6:38 PM in response to Kappy

I agree with Kappy, there seems to be some serious system problems. Reinstall as much as it hurts to hear. You could always just get rid of any system third party programs that you have. Just clean up the system as much as you can so as to resemble a new install. The MacOSX is a wonderful system that can manage it self out. Before reinstalling try to get rid of all junk installed

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Answer 7

phixer64

Level 1

29 points

Aug 11, 2006 12:07 PM in response to Shadow Fox

Hi Shadow Fox, lloks like your going through the same situation as I have been going through. Alos, a few other users have had problems with DSL connectionsas well

Hi, recently update from 10.4.6 to 10.4.7. the problems that i now have is my 8Mb connection is now crawling along at 1.8 - 2Mb!. Have checked with my ISP. They say everything is fine there end, must be something with my modem etc. Using D-Link DSL 300 T, have had no problems with this before, its only in the last week or that is happened, Could a security updated be the cause?

Looks like that I might have to clean install OS X 10.4 with achive option, I have so much in Applications folder etc, All, other stuff like iTunes/iPhoto are stored on another drive. Then update using either the combo to 10.4.6.

Have now, clean installed a new system 10.4.0 and used the combo updater, to no avail. Have checked all cables etc. But the problem still persists.

Gone through all the options on Network prefs.

Download speeds are still around 1.3 - 1.8 Mb. (254kbs) where's the other 300+ ??? Any others out there, had the same problems???

I've also reformatted the hard drive, reinsatlled OS X, applied all updates, and even gone and got a new Netgear DG834 modem, and still the problem persists.

Must be an Apple thing, cos, my fiancee's PC is fine.

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Answer 8

Aug 11, 2006 5:24 PM in response to phixer64

Me, too.

Comcast, OS X 10.4.7

Mac Browsers at Skeakeasy.net: 1.5 - 2.0 Mb

Same machine running Virtual PC: 7.5 Mb

Must be in OS X IP stack

C'mon Apple - give us some help!!!

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Answer 9

Aug 29, 2006 7:10 PM in response to WindozeKiller

SOLUTION SOLUTION SOLUTION

Although the ultimate reason is not clear to me, someone else may have that information. Here is the answer that has resolved every case of this I have seen and following is just the latest example.

Get a new Cable Modem. Specifically, one that has TurboDox acceleration in it.
For example, the Motorola SB5120.

I just was out at a site today with a BRAND NEW Comcast installation and the modem provided was a Motorola SB5101 (Brand New and according to the Comcast tech, fresh from the warehouse and all they had.)
Speed tests from www.speakeasy.net/speedtest on a New Intel iMac AND a MacBook Pro were 2-3 Mbps on a new install. The Comcast tech did not have an answer to why the speed was not what it was supposed to be and left it at that. I had the client go buy a Motorola SB5120 and (after Comcast provisioning) ran the same speed tests. With the SB5120, speedtests were at 18Mbps.

Again, I do not know why a Windows PC runs fast and a Mac runs slow on the non-TurboDOX modems, but I do know that using a TurboDOX modem resolves this issue. And yes, I did look and compare the SB5101 vs. the SB5120 and the SB5101 does NOT list TurboDOX but the SB5120 does.

I hope this helps everyone.

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Answer 10

BDAqua

Level 10

239,189 points

Aug 29, 2006 7:16 PM in response to Karl Wojcik

Apparently the SB5120 is the only Moto without a Broadcom chipset, and the reason it works...
http://discussions.apple.com/thread.jspa?threadID=614605&tstart=15

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Answer 11

Aug 29, 2006 8:05 PM in response to BDAqua

Apparently the SB5120 is the only Moto without a
Broadcom chipset, and the reason it works...

Not True. The Motorola SB4220, which I have, is listed as a TI chipset. My speedtests are 7-8 Mbps consistently. HOWEVER, just down the road, is someone with an SB5120 who clocks in at 12-20 Mbps.
Go figure. It must be something other than JUST the chipset. Maybe a combination of the chipset AND DOCSIS 2.0?
Is the secret TI AND DOCSIS 2.0? Does TurboDOX make any difference?
Anyway, It seems like there are SOLID Solutions out there for people to get the full speed using a Mac. Unfortunately it just took some time to get these solutions.

Good Luck to everyone!!!! As for me, when I run into the issue, its off to get an SB5120 because that has always solved it for me. (Your results may vary, Some restrictions may apply)

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Answer 12

BDAqua

Level 10

239,189 points

Aug 29, 2006 9:10 PM in response to Karl Wojcik

I think you can be proud that you found out what you did on your own!:-)

But the thread doesn't address any TI shortcomingsadvantages, (and perhaps the SB4220 isn't a current model covered by that thread... don't know), TurboDOX appears to be a TI technology and completely aside from the Broadcom chipset issue in my mind...
http://www.ti.com/corp/docs/turbodox/popup7.htm

The fact it seems, is that the SB5120 is a Moto product without the Broadcom chipset & works for Macs.

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Answer 13

Shadow Fox Author

Level 1

4 points

Sep 1, 2006 11:11 AM in response to BDAqua

UPDATE:

I did use IP NetTunerX again to tweak parameters (most notably the UDP stack, and TCP window size).

I got full speeds- for the time of the trial software. Since it's now expired, I have to spend $30 just to keep the full bandwidth I already spend $50 a month for!!

This is ridiculous. Is there a manual way (i.e. via Unix Console) to make the changes I made in IPNetTunerX? There is no reason for me to have to buy an application just to keep my broadband speeds adequate, when I can go to my girlfriend's house, and be completely fine (Bellsouth modem there, and Toshiba here).

Has Apple even addressed this as an issue yet?

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Answer 14

Shadow Fox Author

Level 1

4 points

Feb 23, 2011 11:00 AM in response to Shadow Fox

Moved from location which was a solution in itself and I now have Comcast 50 Mbps broadband. Apparently my old ISP regularly sent scripts to change MTU values directly on the modem itself randomly as part of their "housekeeping" to insure you didn't bridge the modem with a router. Needless to say, I cancelled the service and demanded a refund as this was NOT part of the original service agreement I signed up for.

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