Transmission and it's weird OS X file transfer effects!

[vialli25]

Hey

I've just got a new iMac and am running my MBP side by side whilst I get it all set up.

I enabled file sharing over my wireless N network and transferring files between the two was a dream...until whilst I was transferring my Aperture library it crawled to a halt.

I suspected it might be a Transmission download on my iMac blocking up my network, so I paused the transfer, but it didn't make any difference.

So I decided to use my external HDD. I plugged it into my MBP to get my Aperture library and whilst it started transferring over snappily, it got to only 70MB and then crawled.

I still had a sneaky suspicion that Transmission might be causing it, so I quit the program entirely, and then my Aperture library started copying to my external HDD really fast!

My question is, why would having Transmission open on my iMac, slow down file transfers between my MBP and an external HDD?

I could understand if it was over the wireless network...

 

[r.j.s]

Transmission and Aperture are both trying to use the internal HDD at the same time. Since they have to share, file transfers can be slow.

 

[vialli25]

Sounds like a reasonable explanation. However, Transmission was running on my iMac, but I was transferring my Aperture library from my MBP to an external USB HDD.

Completely independent of each other. As soon as I closed Transmission on my iMac, the transfer on from my MBP to my HDD significantly increased in speed.

 

[calderone]

Sounds like a poorly configured network.

If you don't port forwarding, you are likely flooding your network with packets trying to find the proper destination (your iMac).

Your MBP was likely choking on the packets. Try to recreate this scenario and use a network traffic analyzer (Activity Monitor will do) and see how much data is hitting your MBP.