Faster Boot Times By Reducing 'Suspend' Latency? 11
Miles asks: "I'm planning to building a car MP3/DVD/Navigation/RealTimeAutomobileDiagnostic System. I've decided to use Windows95/98/ME as the OS, for the software I want to run. I've seen similar car computers that take 30 seconds or more to boot, however I want to get the boot time down to 10 seconds. I plan to use "suspend to disk" instead of just powering off the computer to achieve this and it'll just reload memory from the hard drive. I tried to search for HD's that have low spin-up times, but high transfer rates, and have come up empty. IBM's microdrive has a 0.5s spin up time, but only reads at 4MB/s. Another option is flash memory that simulates an IDE drive, but the maximum transfer rate I've seen is 8MB/s. Larger drives can read at 50MB/s, but take 8 seconds to spin up.
Does anyone know of a storage medium that can be written to everytime the computer is shut off, and started up and read from in under 10 seconds (the less the better)?"
"Capacity is not an issue (as long as it is 64MB or more), because I'll have a separate conventional drive to store data. If there are better options than using suspend-to-disk, please tell me about them."
Re:uptime issue (Score:1)
Oh, dear... (Score:2)
The problem is, Win9X simply cannot handle long uptimes, and while sleep mode doesn't render the system any more unstable, all that time you're running the OS will.
You'll get more mileage (no pun intended) out of NT. It does still have to be rebooted in a regular basis, but because cars don't typically run continuously for weeks as a time, you can go for far longer than the typical NT installation.
Your best bet would be to find something more stable that supported suspend-to-disk. The only problem is, I don't know of anything that can do that. Linux is more stable by a long shot, but last I checked you couldn't suspend to disk. MacOS can be made to do suspend-to-disk, but is certainly not as stable as NT. People have successfully made car-based MP3 players based on both Linux and MacOS (never heard of a Windows-based one but I don't doubt they exist). But you're really doing something different here with the suspend-to-disk feature; I like the idea (lower audio "warm-up" times are a Very Good Thing) but I'm not sure how it can feasibly be done with any of these three OS'es. You're going to have to look further afield.
But if you can get something running, be sure to post about it here; I like this idea.
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Re:Linux suspend to disk support (Score:1)
Simple: use dual systems (Score:1)
... while you're using the other to play music, and reboot that one on the next trip
EJB
Re:Mmmmm (Score:1)
Perhaps you should consider that NT4 is now at SP6a. Maybe that's been fixed?
Linux suspend to disk support (Score:1)
I mean if the _only_ reason you are using windows is because linux is missing some wanted feature, then maybe the community could build it?
What would it take to add it?
I guess kernel support would be needed to load/save kernel memory to a boot drive, plus a modified boot loader that could init the os that way. I suspose most of the harware would need to be re-initialised as well.
There are enough linux laptops out there that this feature could be in demand. Furthermore we (the community) could make it more useful than commercial versions...
i.e. On top of normal suspend/resume the user could:
Start up their computer and save multiple different states, and allow the boot loader to select one -- i.e. I could have a prepared boot that goes straight to a logged in X, vs. a second one that goes to a terminal w/o X started. All while still benefitting from high-speed booting.
Disscussion?
Re:uptime issue (Score:1)
you can run it for a very long time without rebooting.... but some things may magically stop working (i run win2k on my school issued laptop, its not horrible, or i'd have switched to debian, but its not perfect either)
Brave man (Score:4)
How about a CF card that (or EEPROM??) that contains enough to get the session started while the other media spins up? The "state" would be maintained on the instant-on media. There might be a small delay to complete functionality but it will appear to be instant on (which is the real need, I my opinion).
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Cool! (Score:2)
The only thing that has held me back (well I'm also broke) is the thought that everytime you hit a pot-hole, your going to tear your disk to shreds. I've been thinking of a way around this, such as suspending it by springs from the roof of the trunk, or pacckaging it in bubble wrap, but it still seems like it would get quite a jarring.
Also what about heat, it doesn't seem like an already old PC would last very long in a hot car and/or trunk, what would be the solution? Just use a lot of fans?
Why Win9x ? (Score:1)
Depending on the kind of CPU you're going to use, wouldn't a small cheap low-power CPU suit better than a hungry Wintel chip ? You could then offload the MP3 decoding to a dedicated processor like the MAS3507D.
I could tell you more, but then I'd have to kill you. If you're really designing a car-based PC for audio and video, you should know better than to use desktop hard and software.
Good luck!
Use QNX? (Score:1)