PC Mechanic, New Article

Posted: 04 Feb 2011 03:00 AM PST

While wireless connectivity is convenient, there are some things that still require the wire – namely if you want the fastest possible data transfer rates due to the fact Wireless G at best is 1 to 1.5MB/second. In addition there are also instances where wirelessly connecting a device is overkill. For example, wireless printing is still prohibitively expensive compared to simply connecting a longer USB cable.

Below is some quick information on how long of a wire you can use before signal degrades.

Category 5

Maximum length: 328 feet / 100 meters

Most people refer to this as ‘network cable’ or CAT-5 for short. This is still what most people use in the home for wired networking.

You will run into signal problems starting at around 250 feet if the cable is old, pulled too tightly, crimped in certain places, etc. In order to achieve full signal at maximum length, the cable must be installed properly from beginning to end.

You can extend the length of CAT-5 by using traditional network hubs. Old routers can also serve as hubs.

Category 6

Maximum length: 328 feet / 100 meters

CAT-6 has the same limitations as CAT-5 when used for 10/100/1000BASE-T purposes.

USB

Maximum length: 16.4 feet / 5 meters

USB cable is very forgiving in the respect that even when crimped or kinked it will usually still get the signal through.

You can extend the length of USB with a USB hub, similar to how you can extend CAT-5 with a network hub or router. For best results, use a powered USB hub.

SATA and eSATA

Maximum length – SATA: 3.3 feet / 1 meter
Maximum length – eSATA: 6.6 feet / 2 meters

SATA = inside-the-case, eSATA = outside-the-case. To the best of my knowledge there is no for-desktop-use PC tower case that is taller than 3.3 feet in height. For server racks/closets, yes it’s easy to go past 3 feet, but for the desktop, 3.3 feet should give you more than enough cable to go from board to device with plenty of room to bunch/tie-down properly.

PS/2

Maximum length: 160+ feet / 50+ meters (estimated)

PS/2-connected keyboards and mice, which a fair amount of people still use, can have cable that with proper extensions can incredibly go past 160 feet and still work. The reason? The signals transferred across the wire for PS/2 are very simple in nature (input devices only), and signals are all 5-volt.

Like with USB cable, PS/2-connected cable can take a lot of abuse and still function well.

RS232

Maximum length: Up to 3,000 feet / Up to 915 meters

Unless you’re a vintage PC enthusiast or work in an environment that still uses RS232 serial cabling for whatever reason, you’ll most likely never use RS232. But if you do, here’s the info on how it works:

The official on-record standard by Texas Instruments states RS232 has a maximum cable length of 50 feet. Is this true? Yes. However when in the RS232 world, there’s also capacitance to take into consideration. If you use RS232 cabling and purposely set your transfer speed lower (measured in baud), greater cable lengths can be used.

Said in a simpler way, the lower the maximum transfer rate, the greater the length of the cable can be used.

19200 baud: 50ft.
9600 baud: 500ft.
4800 baud: 1,000ft.
2400 baud: 3,000ft.

You can read up on the full specs plus all sorts of other old-school serial goodness about RS232 here.

Now you know that if for whatever reason you wanted to transfer data across a single wire that was the length of 10 football fields, RS232 can do it.

And if you’re wondering if it’s possible to use 6,000 feet (well over a mile) of RS232 cable at 300 baud, um.. I have no idea, nor do I want to know.

Post from: PCMech. Helping Normal People Get Their Geek On And Live The Digital Lifestyle.

How Far Can That Wire Go?

you and you

Jumat, 04 Februari 2011