Mac OS X 10.3.1 and Filevault Issues Resolved

[ksz]

Originally posted by Sherman
I've given up on it. I think the difference is that your battery gives the signal to sleep, while my battery has no microprocessor on it, that's done by my computer which may or may not do it differently.

Sometimes too much intelligence is a bad thing! At least you're fortunate that your iBook keeps going and going even while the battery meter reads 0%, but sadly you'll just keep guessing as to how much time you've got left.

 

[punter]

Originally posted by cnladd
Re: FileVault, performance, battery life, and capturing DV movies.

...There is always going to be a performance hit when using FileVault.

Hear hear. I don't think not being able to capture dv footage and encypt it 128bit is a bug, I think your computer just isn't fast enough.

Your computer has to do more work to use this feature. The processor will be busier. Battery life will go down. You should expect that.

 

[ksz]

Originally posted by sethypoo
Just to add to this off topic disussion, I am running a 12" PowerBook G4 rev. A, with AirPort Extreme and Bluetooth always on, and I'm averaging 3 hours of battery life, more if I turn off Bluetooth and iTunes. Is this just because I have a smaller screen that eats away at less battery life?

All else being equal, if the only difference between two LCD panels is the number of pixels, the panel with fewer pixels will consume less power.

Similarly, adding more memory will result in more power consumption. All those extra transistors, sense amps, and bitcell capacitors have to be kept powered. However, if the O/S keeps unused memory flushed to 0, then bitcell capacitors can be left discharged, thus conserving power. If a bit is set high (1), the bitcell capacitor is charged up, left alone to idle for a brief moment, then refreshed. If it's left idle too long, the charge naturally dissipates or leaks. But if a bit is set low (0), it's not necessary to charge it or to refresh it. So battery life will depend not only on how much memory you've got, but also on how much of that memory is non-zero. This probably applies to LCD panels as well -- black pixels will consume less power (most of the power is used by the backlight anyway). If someone is familiar with DRAM/LCD design, feel free to comment.

I am getting on average 3 hours 15 minutes of battery life on a 1.25 GHz AlBook with 1 GB memory and Airport / Bluetooth turned on.

 

[sethypoo]

Originally posted by cnladd
Re: FileVault, performance, battery life, and capturing DV movies.

Unless you need your DV movies to be secured, there is no reason to be capturing them to a FileVault-protected directory. There is always going to be a performance hit when using FileVault. We're talking 128-bit encryption on the fly, here. Sure, in normal day-to-day use I don't notice that much of a difference, but there are situations that it can be problematic.

Battery life will suffer when using FileVault, because of this encryption. The processor will be hit more than normal, which will drain battery life faster. If you'd rather have the faster performance, then FileVault obviously isn't for you.

In the past, the easiest ways of acheiving the functionality of FileVault was to have an encrypted disk image or to use a program to manually encrypt your software. Most people would never do this, instead thinking that it wasn't worth the time and effort to go through this manual process. FileVault makes this easier. It's intended primarily for use by those who have a need to store sensitive information on their hard disks. It's intended for people who feel that the security of their files is more important than the performance of their laptops.

A previous poster summed it up perfectly when they announced that they would be trying the updated FileVault again: they said the theft of their data would be worse than the outright loss of the data. This is who FileVault is primarily intended for.

Amen!
BTW, When I had File Vault on, I had no loss of battery life.....

 

[sethypoo]

Originally posted by ksz
All else being equal, if the only difference between two LCD panels is the number of pixels, the panel with fewer pixels will consume less power.

Similarly, adding more memory will result in more power consumption. All those extra transistors, sense amps, and bitcell capacitors have to be kept powered. However, if the O/S keeps unused memory flushed to 0, then bitcell capacitors can be left discharged, thus conserving power. If a bit is set high (1), the bitcell capacitor is charged up, left alone to idle for a brief moment, then refreshed. If it's left idle too long, the charge naturally dissipates or leaks. But if a bit is set low (0), it's not necessary to charge it or to refresh it. So battery life will depend not only on how much memory you've got, but also on how much of that memory is non-zero. This probably applies to LCD panels as well -- black pixels will consume less power (most of the power is used by the backlight anyway). If someone is familiar with DRAM/LCD design, feel free to comment.

I am getting on average 3 hours 15 minutes of battery life on a 1.25 GHz AlBook with 1 GB memory and Airport / Bluetooth turned on.

So does OS X keep the bet set low (0) or high (1)?

 

[ksz]

Originally posted by sethypoo
So does OS X keep the bet set low (0) or high (1)?

Don't really know. This would be useful only IF there is a material difference in power consumption. I am speculating that there is because the memory bay gets fairly warm which indicates that a fair amount of energy is being consumed (and released). However, I'd like to hear from someone with relevant experience.

 

[switchingGeek]

Originally posted by ksz

Similarly, adding more memory will result in more power consumption. All those extra transistors, sense amps, and bitcell capacitors have to be kept powered.

However, you also have to balance the fact that the Virtual memory is going to be used much less. So going from something like 128MB->256MB->512MB might actually increase battery life, since the disk uses much much more power. Of course this depends on how many pageouts are seen on the machine.

 

[ksz]

Originally posted by switchingGeek
However, you also have to balance the fact that the Virtual memory is going to be used much less. So going from something like 128MB->256MB->512MB might actually increase battery life, since the disk uses much much more power. Of course this depends on how many pageouts are seen on the machine.

True, but consider:

1. Hard drives have on-board cache anywhere from 2MB to 8MB. Physical disk I/Os are performed when the cache needs to be written or when it needs to be populated.

2. Virtual Memory implementations in UNIX and Windows NT are similar in several ways. When you launch an application, the O/S treats the application's disk sectors as a memory-mapped file and begins to page-in from that virtual memory right away. Hence applications seem to load and run very quickly because only small segments of the file are loaded into memory.

When a new process is initiated, a page fault is triggered, causing the first page to load. Because the initialization an application performs takes up a fair bit of code, a cascade of page faults occur right away, then subside.

3. Memory that the application allocates from the system heap is subject to VM as well, but this allocation begins life in physical memory and is written out to swap when needed.

Hence, adding more memory does not necessarily reduce the use of VM because applications always start life as memory-mapped files that are paged-in on demand. However, more memory does mean that you have more space in physical memory for larger documents and more concurrent applications.

Power consumption due to disk I/O increases significantly when you approach thrashing conditions. If this is happening, adding more memory will certainly lead to improved battery life.

 

[chuletilla]

10.3.1 and i got no powerbook anymore

great!,

new update, lets do it a fast download...

This seems great until...


I restarted my powerbook and cannot work on my perpectives again, no finder, 1970 date, only floating in my desktop background.

the beachball keeps on spinning from the very beggining

i restarted 2 times more, i turn it off for 30 minutes, and nothing, i disconected from the LAN, and nothing, please somebody have an advice for this kind of problem?