Gigabit Ethernet network: good for HDV/DV editing?

[Shannon Rawls]

So what if I were to add some of those inexpenive Gigabit ethernet cards to all my computers in my studio.

Plug em all up to a Gigabit Switch.

Then get about 3 of those fancy Gigabit "Network Drives", slap 250gb WD drives in em, and plug those into the switch also.

You think that would be fast enough to capture-to AND edit-from in HDV and/or DV??
Seems better then the bunch of FW/USB2 externals we have all over the place now.

- ShannonRawls.com

[Colvin Eccleston]

I was planning on building a gigabit NAS or SAN for dv before I got sidetracked with HDV. I will have to check the numbers but it should be fast enough to move hdv files about because it is the size not the mbs that is changed isn't it?

[Ben De Rydt]

Firewire and USB 2.0 will both be faster and have lower latency.

The major difference is the hoops the data will have to pass through. The OS will see a Firewire or USB 2.0 HDD as just another harddisk, while an network connected drive (f.i. Lacie's Ethernet disk mini) is typically a small server connected via file-serving protocols like SMB (Windows shares) or AFP (Apple File Sharing Protocol).

This means that data has to pass through the TCP/IP and SMB or AFP layer on the drives side and back again through the SMB or AFP layer and the TCP/IP layer on the side of the computer. This will not improve latency. Throughput is limited by the 32 bit PCI bus (max 133 MB/s) on most computers and the protocol layers.

This test connected a Windows station to a RAM disk on a Linux server via Gigabit Ethernet. They only saw speeds in the range of 30 MB/s with peaks of 46 MB/s. This is easily attainable with a single hard disks these days.

The only thing a network drive gains you is the ability to connect multiple computers to the same drive.

[Graham Hickling]

They only saw speeds in the range of 30 MB/s with peaks of 46 MB/s.

That's plenty to edit DV and/or HDV tho'.....

[Shannon Rawls]

I just don't want any dropped frames when capturing, or Coughing & Stuttering whe editing, that's all.

- Shannon W. Rawls

[Rhett Allen]

I used to run on a Gigabit network but I never tried to "capture" to it. I would be afraid of latency issues in the network. Basically I had 3 Dual 800 G4's (with 4 internal drives, 2 in RAID 0, 2 were for dual booting and backups, total of 320GB per machine) set up for editing and could transfer footage between all of them. We later tried to set up the storage on a remote Windoze server but couldn't get more than about 2MB/s through it. Between the Mac's in the same room though we were consistently getting over 100MB/s with "file" transfers. We tested this with files ranging between 100K, 20MB, 100MB and 10GB+ but could never solve the problem with the outside network storage which was run over dual gigabit and fibre channel. Later we decided to move to a fibre Channel RAID in the same room instead but still captured to the internal RAID and used the larger one for storage and backup.

Assuming your network is really slick, the theoretical bandwidth of Gigabit is 125MB/s... theoretically. There's always solutions like the SanCube for a Firewire SAN though.

Oh I might add that I have "edited" over gigabit, just as an experiment, and it seemed to work fine but it still made me a little nervous.

[Eric Bilodeau]

I already did capturing and editing on a gigabit network and it works fine. Our network was based on Gigabit forced computers (you can choose an auto connection speed or force your ethernet to a speed available from your card). I also captured on a usb2 drive connected to my powerbook from a G5 on the remote network without dropped frames. I also did a show with footage from 5 different computers simultaneously on the network edited on a remote computer (one of the drives was the usb2 connected to my powerbook) without a glitch in real time in FCP. Gigabit ethernet worked absolutely fine for me.

In the college where I teach, we have 16 dual G5 2G with 2GB of ram and 2 250GB internal SATA all networked on a gigabit switch (in the same classroom). I did the following last friday: From my dual G5 at a 1600X1200 resolution on a cinema display 23" mirrored to an external projector, I connected to the footage from my external usb2 drive connected to my laptop and another drive from another computer to show examples. I was connected to the other 15 computers using Apple remote desktop 1.2. There was (on my machine) no downtime or dropped frames from any of the footage during my course. Of course, the other computers where displaying at about 10 FPS but my system was working without an itch, rock solid, for the 30 minutes of my theory.

[Shannon Rawls]

OK, well that solves it...I will update my filesharing 100BaseT network to Gigabit and get a few big network drives to work on and off of.

I wonder why they have such expensive alternative options, like those SAN SUPER DAN MAN WAN i know i CAN networks that costs thousands of dollars. What's the advantage?

- Shannon W. Rawls

[Rhett Allen]

I think they are usually geared towards big business networks. I know when we were looking to add a big network attached storage the IT department was acting like it would cost over $100K. I told them they were out of their minds and we could do it even better for under $20K. There seems to be a disconnect somewhere that they don't understand it's a "VIDEO" storage solution meaning, only a few users connecting to BIG files. Their mentality is usually "THOUSANDS" of users connecting to small files. The cache setup is different and that's where the money comes into play. They were also talking about using a bunch of small (around 20Gig) Ultra160 SCSI drives. It can be done so much cheaper and easier than most companies will have you believe.

[Rob Lohman]

I succesfully captured on standard 100 mbit UTP (which is max
10 MB/s, so fast enough). This was in DV though. And ofcourse
it was kinda tricky since bandwidth was limited.

I would infest in good quality brand items. I've seen major speed
differences on 100 mbit UTP between intel/3com and no-name
adapters etc. So this might be even more so for gigabit.

Should definitely work though, and it's great to have central
storage if you have multiple computers who need to access it!

[Ignacio Rodriguez]

The problem with Ethernet, which many people do not seem to be aware of, is that it doesn't run at the rated speed unless crossover host to host cables or switches are used for full-duplex mode. This is because it's used as a shared half-duplex bus, and uses collision detection to allow for multiple users, thus, actual throughput is usually not more than 30% of the rated bandwidth on most LANs. What you need to do is use a direct crossover cable, whis is fine as long as you don't need to share the disk with more computers, or get a gigabit Ethernet switch and connect both the Mac and the server directly to it. You will then see a dramatic speed increase in comparison to normal hub-based connections.

[Rhett Allen]

Oh yeah, forgot to mention that, use CAT6 cable.