Which Macs Support Jumbo Frames?

Hi

I don't know of a list, but why not use one of those PCI slots for an ethernet adapter that will support Jumbo Frames?

Regards
--greg

Hello l008com,

I can tell my Mac Pro does, and my MacBook does. But sadly, my G4 does not, even though it has gigabit ethernet.

If it has an gigabit ethernet then the G4 should let you configure it manually @ 1000baseT with full-duplex + flow control and a Custom MTU option that will let you type in 9000.

Just going from my mac pro to macbook, my transfer speeds jumped from 40MB to 50MB/sec. And that may have been bottlenecked by the MacBook's hard drive.

In theory you increased the MTU by 500% but only gained 25% in the transfer speed. I don't believe that the MacBook's HD was the bottleneck because the slowest HD made today transfers 150MB/s & Firewire 400 is 50MB/s. I'm thinking that the bottleneck is with the Ethernet Cables. Are you using a crossover cable to connect to your Power Mac G4 from another Device? Inexpensive crossover cables that are 2 wire-pair (4 wires) cables won't work with the Power Mac G4 10/100/1000 Ethernet interface. The crossover cable must be 4 wire-pair (8 wires) Ethernet Cat5 or Cat6 cable. But if you're going to use Jumbo Frames you'll need a Cat6a or Cat7 Ethernet Cable.

Good Luck ...

Buzz

l008com wrote:
It has gigabit, but you can't choose 9000 for the MTU size. The max is 1504.

Not true

!http://i11.photobucket.com/albums/a173/hameesh/misc/9000MTU.png!

In order for jumbo frames to work, the NIC and the switch that you have your devices attached to must support them. If the NIC or switch doesn't, you won't be able to set the MTU higher.

Hey l008com,

Is true

http://img38.imageshack.us/img38/6452/picture1rox.png

How the heck do you embed an image in this forum?

Add a ! between the link like this (I add the " " between it so you could see).

"!http://img38.imageshack.us/img38/6452/picture1rox.png!"

and with the " " removed ...

!http://img38.imageshack.us/img38/6452/picture1rox.png!

Anyway, GET IT NOW? 1504 is the limit, even though it's the built in gigabit ethernet on a dual 800 quicksilver G4.

But anyhow now that I have more info about your G4, does it have a built-in 10/100/1000BASE-T Ethernet connector and four-port 10/100BASE-T Ethernet PCI card (RJ-45 connectors)? If I'm correct about this then the gigabit port is an Uplink Port for a Hub, a Switch, another Server, Access Point or some other Network Device. I know that's not much help but the more I know about about your existing Network Setup, the less I guess about it. One thing to keep in mind is that your ISP Internet Connection is slower that 10MB/s anyway plus the their MTU's are NOT the same size and I know why. 😉

But that really doesn't much if your Network Speed is more important than the Internet Speed.

Later ...

Buzz

Well, we have at least two points on the scale.
Is it an Intel/PPC thing?
Next time I fire up my Dual G5 I shall see what the limits are.
BTW: the 9000 figure is on this MBP - a SantaRosa Intel Core 2 Duo.

Maybe another piece in the puzzle:
http://support.apple.com/kb/TA21473?viewlocale=en_US

But apparently the G4 doesn't support them. Hence my request for list of what does and what doesn't.

According to the Apple article posted by madconqueror, you could buy a third party Gigabit Ethernet PCI-X card that does support Jumbo Frames for your G4. And I assume all the new Intel Mac's can use Jumbo Frames but keep in mind that the IEEE 802 committee does not recognize [Jumbo Frames|http://en.wikipedia.org/wiki/Jumbo_Frames] as a standard protocol as of yet.
Thanks for the information about your LAN but I forgot to ask if you were able to use the Internet when using Jumbo Frames. I was just curious about your hardware because I spend a lot of time researching problems posted here as an aid toward becoming a ACSA.

Thanks again.

Buzz

Please note the Power Mac G4 Dual 800 MHz (Quicksilver Generation 1 - PowerMac3,6) does not support PCI-X which was introduced with the G5 models in mid-2003.

Have a look at this card. According to its specifications it supports jumbo frames. ZyXel products might not be the best of breed but they don't put high demands on your purse on the other hand.

Thank you very much madconqueror for that information as I completely over looked that fact. 😟
Live & learn.

Mactracker is an invaluable tool for helping others choose the right hardware.

This Intel card will work in your MDD G4:

http://www.intel.com/products/server/adapters/pro1000mt-dualport/pro1000mt-dualp ort-overview.htm

Dual-port server card, Gbit Ethernet, 64-bit PCI compatible. I have them in older macs then yours and they work flawlessly. Con -not cheap.