[yvovandoorn]

Ok this is really starting to bug me. I love my iMac but why in god's name does it download slower.

I have tried both with the builtin ethernet port and airport express and I just can't get my Mac above 250kbps (2000mbps).

What have I tried so far:
Archive & install Mac OS X
Tried all the utilities like the bandwidth improver someone recommended me.
Tried changing the MTU manually in the Network settings
Fixed permissions and all the usual maintenance

It isn't my cable connection as my Windows PC can easily do 420kbps - 480kbps without any issues both downloading from downloading and the speed tests located at the many websites.

When my Mac is downloading on Limewire at approx 240-250kbps, my internet is super slow on my Mac but still normal speed on my Windows PC.

This isn't just one application, all applications suffer.

What in the world is wrong with my Mac!!

[ghporter]

Are you running Limewire all the time? It likes to suck down bandwidth whether you're downloading anything at the time or not. Try removing Limewire and see if that changes anything.

Also, how are you sharing your cable connection with the PC? That can make a difference.

[yvovandoorn]

sharing via a linksys wrt54g. the pcs are plugged into ports 1-2, mac is port 3 and a switch connecting other pcs is connected on port 4.

i have tried putting the mac on port 1 or 2, changing its network cable, used the airport connection and nothing has made a difference.

limewire was just an example. usenet is capped at 250kbps as well, speed tests do about 1900-2000 kbits, not bytes :-) (speakeasy's speedtest and various others on dslreports.com). all this is different on the PCs connected on the other ports. its speed tests on the same sites are almost twice as fast.

the problem is with mac os x, not the software as this is happening in safari, firefox, camino, internet explorer, etc for the speed tests. usenet (using Unison), limewire.

now what is funny is that performance within the network (copying files via finder to a windows computer via Samba) is not affected.

[ghporter]

You say you've tried to change the MTU in your Mac-it should be 1500 for a cable connection. If it is higher than that, or substantially lower (unless you've been directed to use a lower setting by your ISP) that could have a strong impact on your speed.

The first thing I'd try is plugging the Mac directly into the cable modem and checking your speed in that configuration. This will tell you whether the issue is in the Mac or in how the router is working with the Mac. If the speed is the same (which I'm leaning toward expecting) then you can start tweaking settings while directly connected to the modem and not have to worry about any interactions with the router.

Since you're familiar with DSLReports, check out their Mac tweak information. I think they give some really useful information and even link to a pretty cool tool for changing the pertinent settings (some of which are harder to change on a Mac than on a PC).

[yvovandoorn]

Ok so I have done the various DSL reports tests and they all come back fine. However I have made a complete comparison.

Sorry about that... answered below.

1. A Tweaks test from this page. Simply post the tests URL. Please make yourself pingable.

Mac PC: http://ttester.broadbandreports.com/...Mac&via=normal
Windows PC:
http://ttester.broadbandreports.com/...nXP&via=normal

2. The closest of 2 speed tests from the Speakeasy Test Sites page. Please note the URLs of both result pages for us.

Mac PC:
Seattle Results:
Download Speed: 2057 kbps (257.1 KB/sec transfer rate)
Upload Speed: 234 kbps (29.3 KB/sec transfer rate)

San Francisco Results:
Download Speed: 2007 kbps (250.9 KB/sec transfer rate)
Upload Speed: 230 kbps (28.8 KB/sec transfer rate)

Windows PC:
Seattle Results:
Download Speed: 3863 kbps (482.9 KB/sec transfer rate)
Upload Speed: 337 kbps (42.1 KB/sec transfer rate)

San Francisco Results:
Download Speed: 4120 kbps (515 KB/sec transfer rate)
Upload Speed: 336 kbps (42 KB/sec transfer rate)

3. A Line Quality test from here. Please copy & post the URL in the red box! This could take a while, so you might run this first. If it's too backed up, do it later, if requested.

http://www.broadbandreports.com/spee...2a7465/1784474

4. What type of Internet connection you have (DSL, Cable, Wireless, Satellite), who your ISP (Internet service provider) is and the make, model and type of your modem.

Cable – Comcast.
Motorola SB4100 Cable Modem
Firmware: SB4100-0.4.4.2-SCM01-NOSH

5. If DSL, do you use PPPoE connection software? (Do you have to connect to the Internet?).
N/A

6. If PPPoE, which one? WinPoet, Enternet, RASPPPoE, WinXP Native, etc.?
N/A

7. Which operating system you use? Windows 98/98SE/ME/2K/XP, etc.
Mac PC: Mac OS X 10.4.1
Windows PC: Windows XP SP2

8. What your advertised speeds are (ask your ISP).
4mbit down / 384kbit up from Comcast

9. If your PC is on a network, and/or using ICS (Internet Connection Sharing) or VPN.
Computer is on a network.
Windows PC is plugged into Port 1 on the router
Mac PC is plugged into Port 2 on the router OR connected via wireless connection.

10. If you use a NAT router (Linksys, Netgear, etc.) for sharing your connection and if so, the brand and model of your router.
Linksys WRT54G, firmware 3.03.6

11. How far you are (if using DSL) from the CO (Central Office). Keep in mind that further than 10,000 feet can significantly degrade speeds. Click here to find your distance, or simply ask your ISP.
N/A


Mac results on the Speakeasy speed test page:


Windows results:

[yvovandoorn]

Connecting directly to the modem, without the router. I am still getting the same results.

[ghporter]

For some reason your Mac may not have the appropriate MTU setting. It should be 1500, and that setting should be reflected in both your computer and your router. If you're getting the same results directly connected to the modem, it's obviously a setting in your Mac...Did you read the DSLReports FAQ on tweaking Macs? It has a link to a tool that will let you check and adjust a number of network settings through a GUI. Here's the FAQ post you need.

[yvovandoorn]

With your advice I have changed the MTU to 1500... still same results :-(

[yvovandoorn]

Ok here is even the more mystifying part. I did a clean install (not archive and install, not a CLEAN install) and the problem is GONE!!

What I do know is that my Mac had its settings copied from another iMac G5 in the store since my first iMac had a dead screen after 7 days of use and they replaced it with a new unit and did a restore in the store.

So... something during that process perhaps did something... funny to my Mac.

In any case.. the problem is GONE!!

[ghporter]

I would call what that process did "frustrating," not "funny." There are so many different settings that can affect networking, there's no telling what the store people hosed up. Starting with a clean slate-as in a clean install-obviously eliminated all of their bumbling. No, I'm not going to cut them any slack, because they violated the rule of "do no harm" in giving you an iMac that was not properly configured though their doing.

I'm glad you got things straightened out, and happy surfing!