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100Mbps Ethernet as high-performance 68k storage

TylerEss

6502
I keep waffling back and forth about whether to put my AudioMedia II NuBus board to use in my hifi system, for digitizing high-quality audio.

A big drawback is that a well-performing 68k Mac is going to need several NuBus cards -- the AMII, SCSI (JackHammer or SE-IV), and 10/100 Ethernet (if I'm not going to grow old copying audio files off of it). Maybe a video card, too. Plus, even the fastest CPU accelerators are practically useless for encoding compressed formats.

Then it hit me: It's kinda hard to get better than 10~12MB/s through the disk on a 68k Mac anyway, even with a modern drive and a good SCSI card. If the 100Mbps Ethernet cards are well-engineered, we can probably push almost that much data through one of them instead. If I set up halfway decent network-attached storage that could be accessed by the 68k machine and a modern computer, I might be able to get the same 68k performance as using a good SCSI card... with one less NuBus card and no need to "copy to the network."

Has anyone ever tried high-performance network file sharing on a 68k Mac?

 
It's certainly occurred to me, especially in the case of compacts that may only get 1.5MB/s or less off SCSI, but have PDS ethernet options.

 
Well for a start you aren't going to get 100Mbps off a 10BASE-T Ethernet card.

I copied a 51.4MB .flv video on to my SE/30. It took 4:21.56 (261.56 sec), which by my calculation is about 200KB/sec.

Uploading to the other computer (Mac mini) took 3:17.46, which is about 267KB/sec.

 
My networking knowledge is poor, but what is stopping one from using a NAS (running FreeNAS for example) and accessing your files using an FTP or web browsing program on the 68K Mac itself?

 
Ethernet will be slower then a good Nubus SCSI card connected to a decent HD. Apples 68k ethernet drivers are not that good.

I would think an external HD that can be connected to a much faster Mac would be better then ethernet.

 
Has anybody ever even used one of the AsanteFast 10/100 NuBus cards? They were a pretty late arrival on the market, and IIRC they used a cheap chipset. A few years ago Trag had a bunch of them, I dunno if that's still the case.

Can you push anything like line speed through them, even on a NuBus PowerMac?

 
I think I have one of each 100Mb branded cards, one is in an 840av and I forget where the other one is (950 maybe).

 
The only time I think NAS would be beneficial is if I was using System 6 without a hard drive. Start up with a floppy disk on a 20MB RAM disk and switch the boot volumes and use the NAS for everything.

I think it's pretty silly.

What is the maximum throughput supported by the NuBUS interface? That could be your bottleneck. Given that the SE/30 has a peak hard drive transfer rate of about 3MB/sec, I wouldn't hope for much.

 
Good network file sharing performance on an SE/30? :lol: Certainly not.

The question is about good network performance on something fast like a IIfx or Quadra (or even a PowerMac). We already know we can push about 12MB/s through a JackHammer or SiliconExpress IV... if we could get similar performance (say, 7+ MB/s) out of a modern file server accessed through an AsanteFast 100Mbps ethernet card, that would be way more convenient for storing and exchanging large amounts of data.

(IIRC, normal NuBus's fastest transfer speed is about 20MB/s... an optimized card in an 840AV could take advantage of a 40MB/s mode, at least in theory.)

 
I think 16-17MBs is the most you get out of a quadra SCSI card using the PDS slot (and assuming nothing else is going on). If you are feeding a 10/100 Nubus network card then you need to get that data from a SCSI card so you cut the max bandwidth in half assuming there are no pauses in between (not likely).

 
There are a lot of systematic problems with the network stack in the classic MacOS that I imagine will prevent you from getting anywhere close to wire-speed with a 100Mbit ethernet card. (The entire reason that Apple built UNIX-based file servers like the AWS95 and ANS 500/700 was that performance with the MacOS-based version of Appleshare server was *lousy*.) Granted, I don't even know where you might find good software to benchmark the Appletalk performance of a 68k system, so... how to confirm or deny that gut feeling is an exercise for the reader. (Find an ancient version of Helios LanTest, maybe?)

If you *have* a "NAS" of some sort set up (be it a fast Mac with a System 7/8 compatible version of Appleshare or a *nix machine running Netatalk) and can find appropriate benchmark software by all means I'd say try testing and see if you get anywhere close to "wire speed" even on the built-in 10mb Ethernet on most Quadra-class machines. I'd wager a nickel you get around half that.

(And regardless of the scores, if you're looking at attempting to stream uncompressed audio to a network share in real time all bets are probably off. For uncompressed "CD-Quality" audio you "only" need about 150Kbytes/second, so in theory you shouldn't even need a 100mbit Ethernet card, but I suspect the latency/overhead in the network stack will kill you. It's worth a try, I guess, but...)

 
Well for a start you aren't going to get 100Mbps off a 10BASE-T Ethernet card.
Sure, but you're not exactly going to get fast SCSI in an SE/30 either.

NAS speeds don't have to be faster than the fastest possible SCSI on the fastest possible 68k to be useful. There are many Macs that don't have Nubus slots, and many people who don't have a JackHammer or SEIV in their collection. There are also Powerbooks, where finding a working and large 2.5" SCSI HD is pure chance. And the oldest Macs have far slower SCSI than the Quadras - from memory and without checking, 0.5 or 1.5MB/s.

Given all of the above, there are multiple use cases where even slow LAN storage would be useful.

 
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