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iMAC I7 Jumbo Frames Finaly Enabled
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Dear Bob,
You can also try with the Level One USB-0201 adapter which is older version and which does support the 9K. The drivers for MAC OSX you can find at this page which is OEM manufacturer for this Level One adapter:
https://www.asix.com.tw/FrootAttach/driver/AX88178_Mac_OSX10.4_v2.0.5.zipThe drivers for WIN 7 64 bit you can find here:
https://www.asix.com.tw/FrootAttach/driver/AX88178_Win7_64bit_Driver_v1.14.3.7_WHQL.zip
Why some of the the newest just released USB-0401 adapters
does not support the 9K is stil the question? It supposed to support it but it looks that some of the USB-0401 adapters which are for sale in the USA use the inferior chipset AX88772A instead of the superior AX88178 which for sure supports the 9K. Anyway you can always exchange the USB-0401 adapter fot the USB-0201 if your USB-0401 does not support the 9k frames. But the USB-0201 realy does support the 9K jumbo frames.Best regards,
Gorazd.
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[Gorazd Koncar] “But the USB-0201 realy does support the 9K jumbo frames”
USB is limited to 480Mbits, so even if it did support jumbos, it would not go faster than the internal imac port.
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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Hi,
It can go if you make the network bond between three or four
such adapters because every USB port on the iMac supports
full USB 2.0 speed. It does not act like HUB as the previous
generations of the computers.
You can then stil use the blueteeth mouse and the keyboard.Best regards,
Gorazd.
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Hi,
I just got also several Trendnet USB to Gigabit
apaters to test TU2-ETG HW:V1.3R and they 100%
support 9k jumbo frames. You just download
the latest drivers from:https://www.asix.com.tw/FrootAttach/driver/AX88178_Mac_OSX10.4_v2.0.5.zip
https://www.asix.com.tw/FrootAttach/driver/AX88178_Win7_64bit_Driver_v1.14.3.7_WHQL.zip
And under Win 7 64 bit system devices ASIX AX88178 enable
ethernet 9k settings. It realy works. And it has the best chipset!Under Mac OS you enable under ethernet settings under ASIX88178 adapter the MTU to 9000.
And if you have several adapters you can make bond between them.
Best reagrds,
Gorazd.
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[Gorazd Koncar] ”
Under Mac OS you enable under ethernet settings under ASIX88178 adapter the MTU to 9000.”Did you read my post? USB on the iMac only supports 480Mbps. So you can set the adapter all you want to 9000, you’re not going to get full Jumbo Frames through the USB port.
Maybe the adapter can do it, but the i5 and i7 iMacs can’t. Unless you enable Jumbo Frames through the Ethernet Port on the iMac itself and NOT through some external hardware combination, you are NOT getting Jumbo Frames through to the iMac.
That’s the last I’ll say about this.
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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Sorry to be late in responding. I think there’s a lot of confusion over the issue of jumbo frames, segmentation offload, and the new i7 performance.
The new imac (and the new Mac Book Pros) use the Broadcom 5764 chipset and it does not support jumbo frames. It supports a feature called TSO (transmit segmentation offload) that is meant to provide jumbo frame performance without the requirement of switch and partner support. Large packets get handed to the card, and it chops them up and applies headers. This saves the OS the trouble. That’s all good and true enough.
On the receive side, you still receive 1500 byte packets. The receiver has to strip the headers and reassemble. This takes a lot of CPU. It generates more interrupts and more context switches. It causes more work for the server. One solution to this is receive side coalescing, but no gigabit chips today support that. (The Intel 82599 10Gb chip on our newest 10Gb card does). So for the present, when an imac is reading in video, there’s 0 jumbo frame “help” so to speak. It’s full on tiny packets.
As for performance, I don’t have a good quantitative answer for what you lose using an i7 vs an older core 2 duo. Walter made a qualitative judgment that the older system does a better job and doesn’t drop. He has some fairly complex timelines. In house, I find my older core 2 duo laptop was about on par with the new imac. I would not recommend either for serious editing. (When I say serious, I mean at least 2 active Pro Res HQ streams coming over the wire at 60MB/sec. If you are doing DV editing or something lower bandwidth than pro res, I’m sure the imac is fine)
The USB dongle sited here was tested by Bob Z and it didn’t support jumbo frames. Since USB is limited to 480MBits, it’s also clear it won’t get us to 2 Pro Res HQ streams. So it was a non-starter for me. Even if it did jumbo frames, I would not expect to see more than 60MB/sec over the wire and with overhead, that won’t guarantee two Pro Res HQ streams (although in practical use, it might be OK for short things).
So all this being said, I think if you are a pro res editor, and each stream is a reasonably large fraction of your gigabit bandwidth, you need a mac pro. If you are doing something else, imac, mac book pro, mac book, mac mini are all potential candidates for you. Just be fore-warned that they won’t compare to the capability of the larger system.
One last note, I prefer it when we can get one of our gigabit cards in the client. We have tools that let us dump stats and see the state of the chips. Apple doesn’t have anything like that, so when something hangs, it’s very hard to debug. We’ve had problems like this recently. With our PCIE cards, I can dump all sorts of good stuff to see why it hung.
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New imacs out today – anyone heard if they have a new ethernet setup (fingers crossed)
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They specifically call out jumbos on the mac pro and they don’t on the imac, so I think the imac still does not support them.
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[Dylan Murphy] “New imacs out today – anyone heard if they have a new ethernet setup (fingers crossed)”
We don’t know yet. The new Mac Pro’s specifically mention Jumbo Frames. The new iMacs do not. Still searching to see which Ethernet Controller is actually in the iMac.
Doesn’t look good since they don’t mention it.
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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Shoot, the mac mini specifically points out Jumbo Frames and the iMac does not. So what does that tell us.
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