
2007 ATEN Technology, Inc. www.aten-usa.com
SWITCH MODEL A (The Detailed Spec):
SWITCH MODEL B (The Detailed Spec):
UXGA
1600 H x 1280 V @ 75 Hz (1920 H x 1200 V @ 65 Hz)
500 ft console-to-computer, 1280 x 1024 @ 70 Hz,
1000 ft console-to-computer, 1024 x 768 @ 65 Hz
200 MHz, -3 dB (300 MHz, -12 dB)
UXGA
1600 H x 1280 V @ 65 Hz (1920 H x 1200 V @ 50 Hz)
500 ft console-to-computer, 1280 x 1024 @ 65 Hz,
1000 ft console-to-computer, 800 x 600 @ 60 Hz
200 MHz, -6 dB (300 MHz, -18 dB)
Format
Resolution (w/ 200 ft total cable)
Maximum Cable Length
Bandwidth
Format
Resolution (w/ 200 ft total cable)
Maximum Cable Length
Bandwidth
XGAForma
00 ft console-to-computer, 1280 x 1024 @ 70 Hz,Maximum Cable Len
t
00 MHz, -3 dB (300 MHz, -12 dB
Bandwidt
X
A
rm
00 ft console-to-computer, 1280 x 1024 @ 65 Hz,Maximum Cable Len
t
00 MHz, -6 dB (300 MHz, -18 dB
n
w
t
As a guiding principle in video, the better set of electronic circuitry (wider bandwidth, lower imped-
ance, better output amplifi ers and internal buffering), the higher the resolution and the shaper the
image at the end of a given length of cable.
Refresh Rate is an often ‘hidden’ spec. Listed in Hz (Hertz, which here means video frames per sec-
ond), the maximum supported refresh rate will vary with the chosen resolution (HxV pixel bitmap).
Higher refresh rates at any given resolution require a wider video bandwidth (see below) which in
turn demands better components in the KVM switch and better quality cabling. In the example
above, Switch A really did not deliver 1920 x 1200 pixels on a par with Switch B. However, Switch
B delivered that resolution at 50 Hz versus Switch A at 65 Hz. Switch A’s conservative manufacturer
decided to advertise a resolution at a better refresh rate of 75 Hz. Note that at the same 1600 x 1280
resolution cited by Switch A, the initially “better looking” Switch B can only deliver a 65 Hz refresh
rate – substantially worse.
Bandwidth is a specifi cation that interests engineers versus end users but can be pretty telling in
terms of image sharpness through a KVM switch. Too much bandwidth can allow internal oscilla-
tions (feedback) to occur that could degrade the signal and damage a device. Low bandwidth trans-
lates to inadequate sharpness or color resolution or just too low of a bitmap (H x V pixels) at a given
refresh rate. In order to spec an “honest” 300 MHz bandwidth as noted in the example above, the
switch’s video output power should be down 3 dB at 300 MHz.
Why Network Administrators Should Explore the “V” in K-V-M Switches
-P09-
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