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Author Topic: Expected network throughput on Mediator?  (Read 5239 times)

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Offline danbeaver

Re: Expected network throughput on Mediator?
« on: January 04, 2015, 09:04:16 AM »
Well, 100 Mb/s (megabits per second) equals 12.5 MB/s (12.5 megabytes/sec) with no overhead (error checking,mostly), but only about 50% can be used, so 50 Mbits/s data transfer =~ 4.7 to 6.0 MB/s (max).  Now you are getting < 1 MB/s, so there is a bottleneck.  The Buster chip limits the estimated 150 MB/s Zorro 3 speed to about 13.5 MB/s and the limit on Amiga to PCI card in a Mediator seems a max of 12 MB/s.  Jens of icomp.de says,  "Roadshow is a commercial product still available today, but since it does not reach the speeds that AmiTCP/Genesis can reach" but I can't find results of his testing.  He does state elsewhere, "Transfer rates of over 1600kBytes/s [1.6 MB/s] have been measured with the X-Surf-100. Please note that the classic Amiga architecture and the current TCP/IP stacks for the Amiga don't allow saturating a 100MBit Ethernet link. Performance in your system may be slower due to CPU performance and programs running in multitasking."

I think that somewhere in there is your answer.
« Last Edit: January 04, 2015, 09:21:24 AM by danbeaver »
 

Offline danbeaver

Re: Expected network throughput on Mediator?
« Reply #1 on: January 04, 2015, 08:48:25 PM »
The X-surf 100 has tweaks for AmiTCP in the SANA2 ENV file and AmiTCP version 4 is available from Amigakit as Easynet Pro.  As Jens posts commonly on EAB, I'd search there for the tweaks.

I WTF'd your findings in the above post too.
 

Offline danbeaver

Re: Expected network throughput on Mediator?
« Reply #2 on: January 05, 2015, 09:14:35 AM »
The Mediator throws a few things in the calculations, but most of the settings (such as MMU) have nothing to do with an 060 board.  The graphics memory sets aside 32 MB (above) for uses as graphics, with 1 MB required for the pseudo-DMA and the rest under the later PCI.library useful as system RAM.

Note that the 1 MB pseudo DMA eats read/write cycles for every 1 MB of data transferred on the PCI bus.
 

Offline danbeaver

Re: Expected network throughput on Mediator?
« Reply #3 on: January 05, 2015, 09:49:26 PM »
Oh, I didn't know that
 

Offline danbeaver

Well, at least the 94 Mbs is reachable in a closed laboratory setting between two PC's with no hubs and using ttcp (Test TCP) provided the "sender" only sends and the "receiver" only receives.

But, to the best of my knowledge we were talking about Amiga and their Ethernet cards and throughput over the Zorro 2/3 bus, multitasking, error checking and the like.
« Last Edit: January 06, 2015, 08:34:38 AM by danbeaver »
 

Offline danbeaver

Re: Expected network throughput on Mediator?
« Reply #5 on: January 06, 2015, 09:43:57 PM »
Since some people have resorted to personal insults, the above mentioned document references results using a specific benchmark in a test lab.

The English language is a rough development of old German (both "Anglo" and "Saxon" are from German regions) with addition of Latin derivations and words that transcend country boundaries.  Spelling and grammar differ from the US to that used in Canada and the UK. Aside from some small typing errors that could be colloquialisms, his grammar is fine.  Some people's use of "effin" for fornication is not, or at least I would never have turned in a document in undergrad or grad school with that word in it; furthermore it is insulting.
 

Offline danbeaver

Quote from: danbeaver;781126
Well, at least the 94 Mbs is reachable in a closed laboratory setting between two PC's with no hubs and using ttcp (Test TCP) provided the "sender" only sends and the "receiver" only receives.

But, to the best of my knowledge we were talking about Amiga and their Ethernet cards and throughput over the Zorro 2/3 bus, multitasking, error checking and the like.

As stated, and kindly read the second article for "Assumptions" and "Other Overheads" since this is not a real-world calculation.
 

Offline danbeaver

Re: Expected network throughput on Mediator?
« Reply #7 on: January 07, 2015, 09:39:03 PM »
Quote from: paul1981;781207
But you haven't explained what part the Fast File System plays in this?

Paul1981 is quite correct (but more to the point about Amiga HDD transfers); those people spitting out "Theoretical" and "Lab Results," fail to remember that the "lab" part is from RAM to Ethernet to RAM.  The original question was on an Amiga doing FTP which involves HDD to Mediator to Ethernet to Server HDD.  These Real World transfers eat CPU cycles and are limited by bus speeds and finally the file system (to some extent), further the server is an unknown and we can't guess the efficiency of it.

I'm going to "guess" that if Jens can get a lab result under optimal conditions for his X-surf 100 of 1600kBytes/s [1.6 MB/s] , then a plain 8139 card sitting on a Mediator that transfers to a Z3 bus and then to a hard drive is going to achieve a value significantly less.