correct me if I'm wrong, but isn't suspend to ram basically "sleep"?
The motherboard (Supermicro 370SWT)I just bought specificaly for my CarPC project has a very interesting feature I wasn't aware of (and I did not try it myself yet) . It is called STR (suspend to RAM) and the machine is supposed to have very short boot time (=<5sec). What it does is that the computer shuts down almost completely (even the PSU fan stops)- except of the power supply to RAM (drawing just a few mAmps of current I guess!). The boot lasts as long as it takes for the HDs to spin up and a CRT (LCDs are faster ) monitor to turn on!
To be honest I don't know if it is the same and the first time I have heard about this STR feature was in the new motherboard's user's manual. It says that it is a feature of BIOS, something that the motherboard in my desktop at home doesn't have (Abit BH6). When I put that desktop into sleep the PSU fan, various LED lights, etc are still on.
STR is great as long as you have a power source... Might not be a good answer for a car though, unless you have an alway-on connection. Maybe dc-dc not wired through the ignition system would work. If you're using an inverter you are still drawing from the battery regardless of what state the pc is in.
[my two cents of pure speculation]
Well, maybe with a DC-DC this could be practical... but I would still fear for my battery if I didn't drive the car all weekend.
I am going to use an ATX DC-DC power supply. The PSUs that meet ATX 2.01 specification should be able to supply up to 1Amps @+5V as standby power to motherboard. Since, the current draw at the PSU's input depends on it's efficiency and the motherboard's power consumption during that state, the only way to tell is to measure it. I'll post as soon as I do it for anybody interested
[This message has been edited by Dimitris76 (edited 12-05-2000).]
Is this a DIY ATX DC-DC, or did you find a commercial source?
ATX DC-DC with any significant amps has always been a myth I thought.
It is the ATX DC-DC, 250W commercial power supply unit SPS-DX250H
Who is the manufacturer and where did you purchase this power supply?
A carputer?!? What in the hell is that?