Macbook Pro - Gigabit ethernet slow download vs fast upload

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Level 1

18 points

Macbook Pro - Gigabit ethernet slow download vs fast upload

I've just reinstalled a clean OS install of snow leopard 10.6.2 onto my macbook pro - early 2008. I just happened to start copying larger files around to restore my setup to where i want it to be only to notice that downloading over ethernet was proving slow.

On more analysis i've confirmed cabling is fine (my old macbook gets up to 30meg/s download on the same connection on the same files) but for some reason i'm getting much faster upload that download.

Basically copying some large files i'm getting

11.7MB/sec download
85MB/sec upload

to the same server, similar files.

What has gone off? I'm tempted to try booting my old OS over USB and seeing if it demonstrates the problem..

I've tried dabbling with the ethernet configuration but there is nothing fixing this problem.. It's coming up as gigabit and i'm getting faster speeds than i ever have had on the upload.

Other machines on the same network wired are having no problems, and as i said my old macbook on the exact same wires i've tried has had no problems either.

Help!

Macbook pro intel 2.4 core 2 duo, Mac OS X (10.6.2)

Posted on Nov 27, 2009 10:15 AM

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Answer 1

jimbobuk Author

Level 1

18 points

Nov 27, 2009 10:36 AM in response to jimbobuk

ok i just booted into my old drive over USB.. exact same problem 11.7MB/s download. However having just booted back into my current system all is well and its screaming at 80MB/s both ways.. I've never seen these kind of speeds before with it usually taking me a minute or slightly less to do a gigabyte of data, where as at 80MB/s its more like 15 seconds or so.

My question is what is going on?! 🙂

I'd rebooted countless times before and it had made no difference.

I guess the only thing i did do was disconnect my router as i was paranoid of mobile.me syncing going silly as i'm using the same machine name for this reinstall as i was before, so i disconnected the power on my router to allow me to not be connected to the internet and disable mobile.me on my old setup.

This is not the first time that i've encountered strange behaviour with network speeds on ethernet.. Typically they've been improved by rebooting machines if required, but i've never seen one so stubborn as this.

I guess i'm concerned something is effected in the hardware of my mac, something intermittent perhaps.

Well for now i'm happy with the speed improvements but if anyone else has encountered issues with their ethernet networking performance i'd be glad to hear of any thoughts or experiences.

Cheers

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Answer 2

mwenzel

Level 1

0 points

Jan 4, 2010 4:05 PM in response to jimbobuk

I have the same problem as you reported. ftp download from the OpenSolaris server to the Mac OSX client is at approx. 20 MB/s, wheres Upload is approx. 50-60 MB/s. Between the two systems there are two gigabit switches: one main (TP-Link TL-R4199G) and one hub (Airport Extreme).
I tried many configurations, and the following modifications all had no or only insignificant effects:
- Rebooting everything
- Changing cables
- Bypassing the Airport Extreme and plugging the client in the socket to the main switch
- Changing network protocol to smb or nfs
- Experimenting with TCP parameters like buffer sizes and net.inet.tcp.delayed_ack
- A Win 7 PC connected to the Airport shows the very same results!!

Believe me, it drives me nuts that my Gigabit Ethernet is crippled down to 20 MB/s and I cannot find the reason. Any hint is much appreciated.

Markus

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Answer 3

Feb 5, 2010 12:04 PM in response to mwenzel

I have the exact same problem - but much worse.

I have a download speed pending between 1Mbit to 7Mbit, but a steady upload speed.
This came as soon I connected it to a gigabit-switch (TP-Link), if I return to the 100Mbit switch I get steady connection both ways in about 100Mbit.

Have you found any solutions?
/Fredrik

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Answer 4

Feb 5, 2010 12:33 PM in response to Fredrik75

But I need to clarify, the other machines(Windows/Linux) connected to the gigabit-switches dont have any speed problems.

/Fredrik

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Answer 5

Feb 6, 2010 11:32 PM in response to Fredrik75

I'm noticing similar issues on my laptop. I'm not sure what's causing it either. I have a NAS server, an ubuntu desktop, and my laptop all connected at 1gig full duplex hardwired. The laptop uploads at about 30MB/s and downloads are around 40MB/s. The ubuntu desktop can transfer to and from the NAS server at about 75MB/s. I was trying to figure out how to get better overall throughput when I noticed something really odd... I was testing ftp transfers to the NAS server from my laptop when I uploaded the same file a second time. The first time, it uploaded at about 20MB/s. The second time it uploaded at 112MB/s - as if the file was cached in memory or something? I don't see where cacheing would be playing a factor here. The ftp application certainly doesn't cache. I can only assume that hard drive cache? Any other ideas?

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Answer 6

Mar 12, 2010 2:30 AM in response to jimbobuk

Just noticed that I get much better transfer-speed and stability when testing with a vmware guest machine (windows 7 configured as network bridge) on the same imac. So its clearly something with the software/os not the hardware.

/Fredrik

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Answer 7

JulianY

Level 1

0 points

Jul 16, 2010 1:35 AM in response to jimbobuk

did you ever solve this this, i have exactly this problem both wifi and wired download crippled to 20 Mb

Julian

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Answer 8

stevo-za

Level 1

0 points

Jul 16, 2010 7:40 AM in response to jimbobuk

Hi Guys,

New to the forum, just found a possible solution and thought I would share it with you as a customer of ours is also having the same problem.

Seems to point towards defective logic boards in the Macbook Pro's, have a look at this thread for more info and when you take it into Apple, take your Gigabit network switch as well so they can test and not blame it on the switch or cabling.

Link is http://forums.macrumors.com/showthread.php?t=686707

Message was edited by: stevo-za

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