Gigabit Jumbo Frames on Broadcom 57xx v 8.48

Question

Hi, I am wondering if the above Gigabit LAN interface on my Precision M65 form October 2006 supports Jumbo Frames.   Also, I seem to have trouble getting 'up to speed' on gigabit connections - despite the netw. connections menu stating that it is running 1Gbps. Is there anything I should tweak with in XP.pro SP2?

crackinchris · Answer

I doubt very much your M65 will support Jumbo Frame on the standard card, you'd have to buy an adapter. Plus the switch you are connecting too will also have to support it. If you're not getting 1gb connection already and only 100mbs, its because you're not connected to a GB switch. It'll only be a 100mb connection. Isn't a GB connection fast enough for you ?!?!?!!! What are you transferring??

BK11 · Answer

Thanks for taking the trouble to reply. I am connecting my laptop directly to a LaCie Big Disk 1 TB disk for backup purposes. The disk supposedly supprts both Gigabit net and Jumbo Frames, which I have enabled in its admin setup.   Nevertheless, when copying all I get is approx 3 -4 Mbytes/s.  I expect that there a many settings that could result in this lousy throughput - even if the actual 'physical' connection is GB. But I do not know how to check out precise where the bottleneck is.   My need for jumbo frames is of course that I suspect that the bandwidth is wasted in communication overhead and a sevenfold increase would be nice :-)   But I would still expect the rate to be faster - even width a 1300 MTU.

crackinchris · Answer

Is this what you have?: LaCie Ethernet Big Disk Gigabit Ethernet Hi-Speed USB 2.0 1TB http://www.lacie.com/products/product.htm?pid=10882 If so, this has a 1GB network interface and a USB 2.0 connection. Have you got a home router that you are connecting your laptop and this hard drive too and communicating over the network or are you connecting via USB lead directly? My concern is if you are only getting 3-4mb/s, this suggest you may be using a laptop that only supports USB v1.0 or 1.1. USB 2.0 has a transfer rate of around 150mb/s in my experience

Message Edited by crackinchris on 05-09-2007 03:45 AM

BK11 · Answer

The above rates are with the laptop either connected directly (no router) to the disk (the one you mention) via the NIC - or directly using the USB. Nothing else is connected to the laptop which is a M65 with a 7600 processor and 2GB of memory. The USB on the machine, I presume, should support usb 2.0, since it was the fastest Precision M65 machine available in october 2006.   LaCie confirms I should get 9-12 MB/s. Something may not be set correctly on the PC and I wonder what?

crackinchris · Answer

I wouldn't bother using a network cable directly connecting to the hard drive.

You need to be using a cross-over cable which I presume? and because there isn't a switch or anything controlling network traffic, they'll be collisions all over the place and that I imagine, is why its so slow.

I'd abandon the NIC connection and stick to USB 2.0. It'll be a lot faster.

BK11 · Answer

Thanks, I tried going through a D-Link 655 GB router by cable. I will also try the USB again and do some more tests, to make sure I know where the bottle neck is.

Networking, Internet, & Bluetooth

Gigabit Jumbo Frames on Broadcom 57xx v 8.48

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