"Mark S. Holden" wrote:

I run a Mach1gto mount, a Dell 9300 laptop, dew heaters and an sbig
st2000xm. The laptop is the largest draw - around 70 watts,

"Tom Jarrett" wrote:

70 watts?! Holy cow, that's more power than my desktop PC with 2
graphics cards in it...

wrote:

You might want to check the power requirements of your cards.

Many "common" desktops have 250W power supplies, and when I
was recently looking for a PCIe-x16 graphics card the power
requirements caused me to do a double-take. For example, a
single NVIDIA 8600GT states on the box: "350 Watt power
supply with a minimum of 18 Amps on the +12 Volt rail" --
that's 216 Watts just for a single, non-overclocked GPU card
with its own fan.

My 2 x Matrox G200 PCI cards each use 3.5 watts -- no fan, not
even a heat sink needed. :-)