OESF Portables Forum
Everything Else => Sharp Zaurus => Model Specific Forums => Distros, Development, and Model Specific Forums => Archived Forums => C1000/3x00 Hardware => Topic started by: conundrum on April 25, 2007, 08:14:43 am
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I'm curious, for those who overclock their C3200s...what speed do you use, and what side effects are there? Does it generate considerably more heat, or is it just a battery drain? Have you had any stability problems?
I saw an older topic from when the device first came out, and I thought it might just be easier to start a new thread for anyone else wondering the same things I am.
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I used to overclock my 3200 when I was running Cacko. Since I switched to pdaXii13 I haven't tried it.
Here is a quote from me back when I did my overclocking testing under Cacko.
As far as overclocking is concerned, it is possible to do it and it is stable if you follow these rules. You can overclock stablily if you choose either of these two settings 520/208/104 MHz or 624/208/104 MHz so, the 3200 can run at 624 MHz. Do not choose either 520/260/130 Mhz or 624/312/156 MHz because these settings will lock up the 3200. On my old 1000 I needed to overclock it to 624/312/156 MHz in order to have smooth full screen,play back for the battle scenes of my anime movies because they were usually stored on my SD card. With the 3200 I am of course storing them on the built-in microdrive which is faster than the SD card slot so overclocking to 624/208/104 MHz is giving me the same results as I got with 1000 with maximum overclocking.
Side effects from overclocking include:
- Z runs hotter
- Z battery is shortened
- Z screen flickers (this one can be quite annoying)
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That's the older thread I was referring to.
The heat and screen issues are what really concern me.
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That's the older thread I was referring to.
The heat and screen issues are what really concern me.
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The heat generated running the entire Star Wars Clone Wars Volume 1 movie was bearable on my Zs. The Z was warmer then usual but not uncomfortable like a Powebook/MacBook Pro gets after an extended heavy load session.
Of course heat is the enemy of electronics so, too much overclocking could technically shorten the life of your Z.
The flickering was just too annoying for me at 624 when I was doing anything but watching a movie.
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That's the older thread I was referring to.
The heat and screen issues are what really concern me.
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Of course heat is the enemy of electronics so, too much overclocking could technically shorten the life of your Z.
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Heat kills batteries especially rapidly.
Your Z internals may survive a number of extended hot-running sessions,
but it will impact the lifespan of your batteries, for certain.
I've heard stories that extended overclocking causes wear and tear on the
CPU core, even if kept cool; but I don't think its likely to be a limiting factor
in our case.
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Even an overclocked Z doesn't get *that* hot. Electronics are significantly more heat-tolerant than people are. And the heat generated is dissipated well away from the battery, so the battery isn't at risk either.
I can understand being cautious about this, but if the Z was getting too hot it would crash well before it got to the point where any damage was a possibility.
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Even an overclocked Z doesn't get *that* hot. Electronics are significantly more heat-tolerant than people are. And the heat generated is dissipated well away from the battery, so the battery isn't at risk either.
I can understand being cautious about this, but if the Z was getting too hot it would crash well before it got to the point where any damage was a possibility.
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actually, degradation of battery performance/life is a significant problem, even at moderate temperatures. Episodes of moderate (or even high) heat aren't too much to worry about; but the cooler you can run, the longer it'll be useful before replacement/disposal.
Heat is the major factor in wear on laptop batteries; if you use a laptop plugged in to AC for stretches of hours to days, you're much better off removing the batteries.
Solid state electronics should be fine; capacitors and things that use electrolytic chemistry are unfortunately not quite as stable. Poor practice with charging (leaving things charged continuously) also hurts cell phone users; they frequently have no idea why their batteries run out so quickly.
Heat is bad for batteries; the rest of your zaurus (maybe LCD?) won't much care.
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To state the obvious and put it plainly: If your worried about damaging your Z in any way (even potentially), don't overclock.
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I once overclocked my C1000 under Cacko 1.23. I had to do it on 624/312/156 MHz to be able to play my favorite NEOGEO games smoothly. In the beginning everything was fine. But then I had occasionally lockups. Something my Z will even lockup just on switching back from 624 to 416. After that I only dare to try 624/208/104, which never had any problems, but it couldn't run my Emu games smoothly. Anyway, I guess the overclock performance will also depend on the quality of your Z, especially when you're overclocking the bus.
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Heat is the major factor in wear on laptop batteries; if you use a laptop plugged in to AC for stretches of hours to days, you're much better off removing the batteries.
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Laptops are in an entirely different class of heat dissipation to the Z. A Z's LiIon battery is not going to see those sorts of temperatures no matter how much you overclock it.
And besides, my point was orthogonal - most of the heat generated by the CPU does not get dissipated into the battery.
What is actually a bigger problem for LiIon batteries is the charging profile. Fully charged cells degrade fast. A 100% charged LiIon cell at 25degC irreversibly loses about 20% of it's capacity per year, even when unused. The same battery at 40% charge and 25degC only loses about 4% capacity per year. That's the big reason laptops which are always plugged in see their batteries degrade. Yes, heat accelerates the process, but it's already bad even at moderate temperatures.
Which actually gave me an idea recently - if you know your Z/laptop is going to stay plugged in for a considerable amount of time, you should be able to tell the charging circuit to not charge the battery past 40%. Of course, you'd need to be able to tell it to go back to 100% mode a couple of hours before you go back to battery power. Maybe even use a scheduler to set those levels according to your routine. That would make a reasonable boost to the life of your battery.
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Yeaaay for some of the most highly reactive elements known to man!!!!
when overclocking i found tat the cpu was hot while the battery was warm however it was cool between the two, i wirte that off as heat due to exsesiv current draw (also can kill litium ion battries)
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What is actually a bigger problem for LiIon batteries is the charging profile. Fully charged cells degrade fast. A 100% charged LiIon cell at 25degC irreversibly loses about 20% of it's capacity per year, even when unused. The same battery at 40% charge and 25degC only loses about 4% capacity per year. That's the big reason laptops which are always plugged in see their batteries degrade. Yes, heat accelerates the process, but it's already bad even at moderate temperatures.
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That's interesting. I had always heard that it's best to keep LiIon cells topped off. I was told to avoid discharging them completely, and that for longest life it's best to top them off regularly. This is what I've been doing with all my LiIons. I may need to rethink my habits.
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I hardly ever leave home in the winter, both of my Z's stay plugged in constantly for at least 8 months.
Then in the summer, they are only on battery power for about a few hours on the occasional days that I pack 'em with me.
Are my batteries going to die prematurely?
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I used to get kinda stressed about maintaining the life of my batteries because there are so many opinions about taking care of them. It seemed like a lot of work.
Now I just use the device, and enjoy it without worrying about the battery. If I get 2-3 years I'm happy and will just buy another battery to replace it (If I haven't upgraded the device).
Maybe I'm just a lazy consumer.
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I was told to avoid discharging them completely, and that for longest life it's best to top them off regularly.[div align=\"right\"][a href=\"index.php?act=findpost&pid=159898\"][{POST_SNAPBACK}][/a][/div]
While it is true that LiIon batteries don't like being discharged completely - you can't actually do it. All LiIon batteries have internal controller electronics that shut off the battery once it gets down to about 2.7v to prevent them from ever being over-discharged.
The only way to make it happen would be to run the battery right down, then put it in storage for many months until self-discharge (which is very small for LiIon) gets it the rest of the way. Even if you only pull out your Z very occasionally you're going to easily avoid that fate.
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i often (almost always) play movies overclocked in 512/624 mhz - i encode them for 640x480, and without this the playback is not really smooth