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- Network Performance Issues
-
-
- A very common question is: "What can I do to speed up my LAN?"
- There is, unfortunately, no cut and dried answer, as LAN performance
- is influenced by many different factors. Discussed here are the
- major issues:
-
- First, note that the "speed of the LAN" can be a couple of different
- things: (1) the physical transmission speed of the hardware
- (generally 2 or 10 Mbps with adapters that Artisoft sells) and (2)
- the effective throughput, or how fast data can travel from one place
- to another on the LAN. The latter is generally what users want to
- speed up, since the former is not alterable.
-
- The one thing that probably affects throughput the most is the speed
- of the CPUs in the machines that are connected to the LAN. Not only
- the server's CPU speed is important, but also the speed of the
- workstations' CPUs. One generally would want to have the fastest
- CPUs for each machine on the LAN, but this is obviously not
- practical, as it can be rather expensive to purchase fast 386
- machines for all users on a LAN. However, if you use 4.77 Mhz XT
- computers as workstations, you can expect that your throughput will
- be slow no matter what flavor of adapter you have in the machine. In
- fact, just increasing the processor speed from 8 to 10 Mhz in a 286
- machine can increase throughput up to 20%!
-
- The transmission speed of the adapter card will also make a
- difference. Generally, with reasonably fast machines, moving from a
- LANtatstic 2 Mbps adapter to an NE3 Ethernet adapter at 10 Mbps can
- double the throughput of the LAN. However, if you have a slow
- processor moving from 2 to 10 Mbps will probably not make that much
- of a difference. This is because the 2 Mbps adapter has a
- coprocessor that does all of the low-level NetBIOS functions, whereas
- the Ethernet adapter does not have a coprocessor, forcing the
- PC's processor to do all of the NetBIOS work.
-
- Adding disk caching to the server will also help. We recommend
- either Golden Bow Systems' VCACHE (which we use in-house currently)
- or Super PCKwik from MultiSoft (which other users have reported
- success with). In either case, you have to configure the cache to be
- "write through," so it does not cache disk writes. In Vcache's case
- this involves adding the switch '/T=0' to the command line. For
- Super PCKwik, use the '/H-' and '/D-' switches. Other caches may
- also work, but keep in mind that they must be configured as write
- through. Caching software should be loaded before any of the NOS
- software in order for it to work correctly.