iMAC I7 Jumbo Frames Finaly Enabled

[Gorazd Koncar]

Hi,

I have done also tests with the new Hitachi external
USB Turbo 1TB and 2TB drives which are lowest priced
on the market compared to WD ones and I was preaty amazed
about the speed. Its is exactly around 33 MB/s and is no droping!
This I until now could not get even from dedicated USB HIGH Speed
Turbo sticks (around 28 Mb/s)! Compare that to WD USB external drives speed(around 13 Mb/s) and you shall see the dramatic difference.

Best regards,

Gorazd.

[Walter Biscardi]

[Gorazd Koncar] “I have done bond network connection under MAC OSX between
both adapters and the connection speed was around 65 MB/s
what is realy incredibile.”

That’s not Jumbo Frames. Are you setting the MTU to 9000 in your Ethernet Settings and then having that stick? With the i7 we had here, we could set it to 9000, but when you hit Apply it would drop back to 1500. With Jumbo Frames your speeds should be around 120MB/s. 65MB/s is really slow.

If you still have that same Broadcom Ethernet Controller I mention in my blogs, you do not have Jumbo Frames. You’re seeing about the same speeds we saw on the i7 machine here. We swapped that machine out for the 3.33 27″ iMac and now we’re back up to 100 – 120MB/s which is where we should be.

Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative Media

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[Walter Biscardi]

[Gorazd Koncar] “After a lot of confusion about the new IMAC I7 jumbo frames
support I have done tests with two Level One USB-0401 Gigabit
adapters hooked to two USB IMAC I7 ports.”

And now I realized you’re bypassing the Ethernet Port to go through two USB ports. That has nothing to do with Jumbo Frames. Jumbo Frames are enabled using the Ethernet controller on a machine. USB is giving you incredibly poor performance using your scenario. People can get 65MB/s using a single USB port and sometimes faster.

You’re just using a jury rigged way to get around the ethernet port on the i7. So “Jumbo Frames” is not enabled in any way shape or form if you’re bypassing the ethernet port and coming in via USB.

USB 3 (if Apple ever incorporates it) will give us speeds plenty fast enough to edit as BlackMagic was showing at NAB this past year.

[Gorazd Koncar] “Please know that IMAC I7 is also realy very fast machine
and I should never go back to previous model of IMAC for ethernet
speed!”

Again, you’re getting HALF the speed you would be getting if you were truly using Jumbo Frames on an i7 iMac via Ethernet. This is not a solution for the i7 to achieve Jumbo Frames. Sorry, nice try.

Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative Media

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[Gorazd Koncar]

Hi,

I am setting the jumbo frame support to the Level ONE adapters
and it stays 9K. The speed is limited by the USB bus but
the 65 MB/s is excellent solution with the bond between
two USB Level One sticks. Plese know that onboard IMAC ethernet
adapter speed is limited to around 24 MB/s because it does not support the jumbo frames. And in testings there were no drop
of the usb speed when both adapters were used simultanously.
So if I then put another USB stick then the speed shoud be around
90 Mb/s and I stil have one usb port free for the dedicated
marked keyboard and mouse and Shutlle PRO all hooked on the
Belkin Hub.

Best regards,

Gorazd.

[Gorazd Koncar]

Hi,

You enable the jumbo frames for the USB stick adapters and the
total bond in the MAC OSX network settings. Please know
that this Level One sticks are the only ones who actualy
support the up to 9k jumbo frames in their hardware
and when they are not manualy set to 9k they sepport 1,5k frames.
The bottleneck is the USB 2.0 bus which start at the around
33MB/s per every USB port. The good thing is that the
speed at the new IMac I7 does not drop when you use two and more sticks per every USB port as this was the case with the previous
IMACS USB ports which USB controllers were basicaly hubs
and the speed was shared between all the USB ports.
So basicaly you could achive even 120 Mb/s speed with four such
adapters and use the blueteeth hub for using the keyboard
and other usb stuff.

Best regards,

Gorazd.

[Walter Biscardi]

[Gorazd Koncar] “The speed is limited by the USB bus but
the 65 MB/s is excellent solution with the bond between
two USB Level One sticks. Plese know that onboard IMAC ethernet
adapter speed is limited to around 24 MB/s because it does not support the jumbo frames. And in testings there were no drop”

Precisely. No Jumbo Frames on that iMac. So the title of your post is completely misleading.

You would be MUCH better off simply going with a FW800 RAID where you can easily get 125MB/s using a single cable with no reason to do this jury rig system you’ve created. Speed will be faster and hookup will be much easier.

This is a great attempt, but it is in no way shape or form “Enabling Jumbo Frames” on an iMac. Honestly can’t see any reason to do what you’re trying to do. Just wait for USB 3 to arrive and then we can all use USB for hooking up drives to edit.

If you really want to use Ethernet properly on the 27″ machine, just pick up a 3.33 Core Duo 27″ iMac like we did here and now we’re running 115MB/s which truly does support Jumbo Frames.

Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative Media

“Foul Water, Fiery Serpent” featuring Sigourney Weaver coming soon.

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[Andy Mees]

Hey Gorazd

I thought I had posted this before but I guess it didn’t go through … just wanted to thank you for taking the time and effort to share with the COW your workaround for this issue. Its very much appreciated. Good job.

Best
Andy

[Rafael Amador]

q[walter biscardi] “USB is giving you incredibly poor performance using your scenario. People can get 65MB/s using a single USB port and sometimes faster. “
Walter,
I’ve never heard of USB performance close to that, neither the one you mention about FW800 (125MB/s).
How is that achieved?
rafael

http://www.nagavideo.com

[Bob Zelin]

This is the product that is being refered to –

https://global.level1.com/product_d.php?id=1012
Supports Jumbo packet of up to 9KB
Supports suspend mode and remote wakeup via link-up and magic packet
Supports Windows 2000/XP/Vista/7, Mac 10.3/10.4/10.5

now, does this actually work ? Can you do an MTU of 9000 on an iMAC i7 with this, and get the CORRECT data stream that many of us use with ethernet connection to a drive array ? I will find out, and let you know.

Bob ZElin

[Walter Biscardi]

Ok, we can put this thread to bed now. Jumbo Frames are not enabled any way, any how on the i5 / i7 iMacs. Bob Zelin researched this further and got this response from Level One.

Hi Bob

It is confirmed that the USB-0401 does not support the jumbo frame and the info has been corrected at the website https://global.level1.com/product_d.php?id=1012

I apologized for any inconvenience

Thank you

Timmy Ngo

So if you really want to use Jumbo Frames in a 27″ iMac, you need the core duo machines. That is working here so far.

Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative Media

“Foul Water, Fiery Serpent” featuring Sigourney Weaver coming soon.

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