Reorganizing your network, accelerating file transfers, and upgrading to faster hardware can all keep your graphics network humming.
Chuck Weger
Net Tools
In the graphic arts,we move big files -- a couple of megabytes per page layout and up to 100 MB or so for a single color image. Luckily, you can speed up a DTP network with faster hardware, smarter configuration, and new network standards. For simplicity's sake, we'll assume that you're using a fast server with fast Macs and disk drives, all on a 10BASE-T Ethernet network, so those pieces aren't the cause of bottlenecks. If you're using a PowerPC-based Apple Workgroup Server, be sure to use AppleShare 4.1, which is significantly faster than its predecessors.
Rearranging Things
The first thing you can do is replace your hub with a switching hub. Ordinary Ethernet hubs put everyone on the same party line; if many Macs try to send files or print at the same time, network speed goes way down. Switching hubs set up a private line between two network devices while they are exchanging data; no other Macs see the traffic. On busy networks, a switching hub can provide a speed boost of around 30 percent.
Network-acceleration software, such as RUN's RunShare (800-478-6929 or 201-529-4600), also looks for network quiet time. It grabs unused bandwidth on the network that occurs between transactions and "fills in the gaps."
If your network is large, you can divide it into separate physical segments with a router. Keep Macs that exchange files frequently and the printers they use on the same side of the router, isolating their transactions from the rest of the network. If your server runs a UNIX, NetWare, or Windows NT operating system, putting multiple Ethernet cards in the server and connecting each to a different network segment will speed things up by giving users on each segment a direct line to the one place everyone needs to go -- the server. Unfortunately, Apple Workgroup Servers don't yet support multiple network cards.
If the bottlenecks have really got you down, move to one of the new network standards. The brightest star on the horizon is Fast Ethernet (100BASE-T). Upgrading all or part of your network to Fast Ethernet means buying new hubs and Ethernet cards and possibly doing some rewiring. If most of your Macs don't transfer large amounts of data, limit your Fast Ethernet upgrade to servers or other busy machines.
Fast Ethernet and 10BASE-T cards are available for NuBus Macs and for Apple's new PCI-bus Macs. With or without Fast Ethernet, PCI offers another chance to speed up network access: PCI's 33-MHz speed beats NuBus' 10-MHz speed by quite a lot.
Stay Off the Net
There's one other way to prevent heavy traffic from clogging your network: Keep the data completely off the wire! OPI (Open Prepress Interface) servers do just that, by making low-resolution preview images for use on your design workstations; those Macs never see the huge, high-resolution image files stored on the OPI server and used in printing. You'll need OPI-compatible server software to employ this option. (For more about OPI, see Expert Tips, March '95, page 113.)
If none of these options moves things quickly enough to suit you, there's always sneakernet.
Chuck Weger is a consultant and conference chair of CONCEPPTS 96.
Figure 1 Directing Traffic / an Efficient Network
Isolating busy network devices from other traffic and/or adding Fast Ethernet (100BASE-T) can greatly speed up a network. If you can't move everyone to Fast Ethernet right away, consider implementing it on servers and on those Macs that must send or receive large files, such as those used for complex image editing.
