Capturing to a networked drive

[JerryH]

I realize this may sound crazy to attempt, but I'm wondering has anyone tried doing this?

I've got two boxes, one with RH7.2, another with Win2K, with shares set up on the RedHat box using Samba, and a 100Mb switch joining them.

I mostly capture DV from my Digital8 camera, which as I understand it demands 3Megabytes/sec. At optimum conditions, the network should move data at about 12 Megabytes persecond, overhead notwithstanding.

I realize there are many more factors involved, but I'm just wondering what I could expect trying to do this over a network, all other things being equal.

[Dr Mordrid]

Yes, I've tried it...but with mixed results. One piece of unexpected network traffic and POOF! Instant frame drops, often in bunches.

So much depends on how well both systems are set up that nothing short of a realtime test will suffice to determine how a given setup will do, even with full duplex NIC's and a switch.

I'd try using a stopwatch to time the copying of a 2 gig video file to your proposed target drive and see how that goes. Watch for any interruptions in the throughput. Math will give you the real transfer rate.

IMHO 'tis better to capture to a local drive absent a DNAS-FC.

Dr. Mordrid

[dZeus]

I think that realisticly you can't expect getting more than about 7-8MBps sustained throughput with samba, and at that speed your NIC will use quite a bit of cputime to transmit at that speed. That's what I've tested with my own configuration, with a 3com 3c905c-tx. Maybe if you've got a NIC that offloads even more tasks to the controller chip, you might be able to get higher transfer rates without straining the CPU too much to influence capture negatively (translating into framedrops).

[Wombat]

Get some NICs that won't demand much from the CPU, and see what you can do about getting a good bit of RAM in the Windows PC, and tweak the caching. Maybe the 8MB/s times can make up for the 1MB/s times. Also, how good is your HD setup on the Linux box?