Level 1

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Download speed too slow (only a third of what is physically possible)

Hi.

Maybe someone can help me. I have a current Mac Pro and a Macbook Pro 17". In my home office I run them both via an ethernet router through my VDSL connection. I can reproduce that the Mac Pro is way slower when downloading files from the internet. While with a certain test site the Macbook Pro maxes out at around 3MB/s the Mac Pro never gets more than 2.3MB/s. The difference becomes even more evident, when downloading files from Apple or other big websites. When downloading files/movies/music the download speed maxes out at almost exactly 1MB/s, while the Macbook Pro still gets almost full speed.

Does anybody know why the Mac Pro is so much slower than the Macbook Pro?

I checked everything again and again. Cables, configuration, switched network jacks, etc... pp... When I just switch cables between the computers, the problem is still there, so the problem must be somewhere within the Mac Pro, Hard- or Software. I hoped that a switch to Lion would maybe resolve the problem, but it didn't bring any change.

Since I have to do big downloads very often (that's why I have a VDSL connection) I really need the speed. It doesn't make sense for me, when the computer perfroms download in just a third of the possible speed!

Any help is highly appreciated! :-)

Regards,

groovebuster

Mac Pro, Mac OS X (10.7.1)

Posted on Sep 14, 2011 5:47 AM

21 replies

groovebuster Author

Level 1

0 points

Sep 14, 2011 2:47 PM in response to Grant Bennet-Alder

I have been through all this before... Network Utilities reports this. So everything seems to be fine. The wiring in my house is state of the art. In the walls I have Cat.7 cables and as patch cables I use exclusively Cat.6 or Cat.7 cables. As stated before, the Macbook Pro doesn't seem to have any issues with the same cables and configurations in all the variationsI tried. It must be a software problem. But I can't figure out what it is...

The hatter

Level 9

61,031 points

Sep 14, 2011 3:18 PM in response to groovebuster

How about adding a PCIe network card?

My problem was a $4.95 filter. I tried all new wiring and cables. I have three lines coming in, and a phone down in basement, never used, that had a bad filter on it. And disrupted my three computers.

What I have read from others and looked into was the Intel chipset has high latency. And THAT seems to be what causes the problems for Mac Pro owners. This is what the reference design Apple used:

http://www.intel.com/p/en_US/support/highlights/server/s5000xvn/

Mac Pro 1,1 - based on Intel Skulltrail platform. The Early 2008 was reference design from SkullTrail II.

One reason I even tried Vista to begin with! ISP was going to come out and run a Windows system to see why my results were less than expected.

When Intel and Microsoft issue drivers, like "patch Tuesday" yesterday for Office, they include detailed notes, not "fixes and improves compatibility" - and nothing more.

This is Intel August 2011 update for my discontinued workstation.

At least they do, and tell you what and why.

http://www.intel.com/support/network/sb/cs-006333.htm

Sorry I misunderstood.

Some people in the past posted that they were getting 300k instead of the 1.5 to 2.0 Mbit they should be getting.

Rural Iowa is getting FIOS, with 20-150Mb service.

Sep 14, 2011 3:54 PM in response to The hatter

If the Mac Pro Ethernet chip set has high latency, maybe it needs to be tuned. Years ago, I tried out IPNetTuner under OS 9. Their newer product for Mac OS X is inexpensive and has a 21-day free trial:

http://www.sustworks.com/site/prod_iptx_overview.html

Oct 15, 2011 9:03 PM in response to groovebuster

I had a similar problem macbook pro has fast download, macpro slow, same connection, both newer models fully loaded. I have cable not dsl...

I found this suggestion (below) on another discussion and it helped a lot. iphone software update download went from 2 hrs to 20 min... still too long, but better. Mac book pro is about 3 min

" [*Then, I finally found the culprit: The automatic MTU!!*

*I couldn't believe it. Such a stupid, basic cause of such a big problem. This is most certainly a BUG.*

*To fix the MTU:*

1. Apple Menu > System Preferences... then Network.

2. On the left, choose Ethernet , then Advanced... on the bottom.

3. Choose Ethernet tab:

. . . Configure: Change from Automatically to MANUALLY.

. . . MTU: Change from Standard to CUSTOM. Put 1452 then click OK. Then Apply at the bottom.]"

(This is as far as I did and it improved immediately without reboot etc.)

"[ 4. Repeat step 3 for all services listed on the left, such as AirPort, Parallels, etc. Press Apply.

5. Turn off your computer, unplug the router, then unplug the cable/DSL modem. Wait 60 seconds, turn on the cable modem (patiently wait for it to come on with full lights active), then the router (wait for its lights, be patient), then your computer.]"

groovebuster Author

Level 1

0 points

Oct 16, 2011 3:08 AM in response to skylineliz

Thanks, but when I tried this out, the download speed got even worse.

groovebuster Author

Level 1

0 points

Oct 16, 2011 3:30 AM in response to The hatter

How about adding a PCIe network card?

My problem was a $4.95 filter. I tried all new wiring and cables. I have three lines coming in, and a phone down in basement, never used, that had a bad filter on it. And disrupted my three computers.

This can't be the problem in my case, since the Macbook Pro on the same network gets way better results. I have a dedicated network in my house with cat.7 cables in the walls. My internte connection is VDSL: Modem -> Router -> Network. My phone line is digital (ISDN). The Mac Pro is the only machine that is having trouble. Also the other cpmputers in the house (wife: Mac mini. duaghter: Macbook) dont' have any issues regarding the download speed.

What I have read from others and looked into was the Intel chipset has high latency. And THAT seems to be what causes the problems for Mac Pro owners. This is what the reference design Apple used:

http://www.intel.com/p/en_US/support/highlights/server/s5000xvn/

Mac Pro 1,1 - based on Intel Skulltrail platform. The Early 2008 was reference design from SkullTrail II.

I have a Mac Pro 5,1. So does that matter for my configuration?

The funny thing ist that I found out now, that the low speeds on the Mac Pro I do not get with all connections on the i-net. An example: Apple! Downloading a software update from the apple servers gives me exactly 1Megabyte/s on the Mac Pro, but around 3Megabytes/s on the Macbook Pro. A download from a certain server here in Germany gives me around 3 Megabytes/s on both machines.

What really makes me wonder is, that the download speed with Apple tops exactly at 1024kbit/s. Is that a coincedence? Or is Apple pulling the hand brake because of some really strange reasons for the Mac Pros? I also don't have any speed issues between computers on the LAN here in the house. I really don't get it... Is that still a latency problem?

Seems I just have to live with it. And that with a computer that cost me more than 4,000.- € overall...

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Download speed too slow (only a third of what is physically possible)