Actual Mhz And Overclocking?

[Tobriand]

it looks pretty cool if you can overclock this divise but you also have to upgrade the ram memory if you want to be able to play better games on it

Nah, you just need to make sure you code your games efficiently, and not use textures designed to look crisp at 2048x1024. Don't forget that the PSP has 32mb (afaik) and pulls out some insanely pretty games.

It's just that a lot of PC games have to look good at higher screen sizes (which doesn't apply to us), or are coded by people who are so used to not having to worry about memory problems that they simply don't (e.g. Zelda Classic loading an entire module into memory rather than only the current screen, thus taking ~100mb for something that you'd normally expect to take at most 15mb).

 

[Gilrad]

So if I am understanding this correctly, this thing is constantly at a variable clockspeed?

Is it determined by application? Like, load up a genesis emulator, and the program says to downclock to the point where it is just able to run at full speed, saving battery?

Or is it a more inherent feature? where, by default it checks how much the proc is pushing and ajusts accordingly?

Overall neat stuff. If 9 hours is the estimate for big and beefy games for one charge, then I would like to see a few extra hours tacked on from low-end emulation.

 

[fusion_power]

Well, I prefer UNDERCLOCKING much more than overclocking, especially on a battery-powered Handheld.
I hope, many Pandora Apps will run underclocked, I think when "Picodrive" onto the GP2X runs at 200MHz, there is no need to run it at 600MHz onto the Pandora (I hope).
Can the OMAP automaticly decide, how much MHz a Program needs? Dynamic and automated clocking would be much more "next gen" than Clocking per hand like we have to do onto the GP2X. - Just a Idea.

EDIT: Gilrad was faster!

Overall neat stuff. If 9 hours is the estimate for big and beefy games for one charge, then I would like to see a few extra hours tacked on from low-end emulation.

Exactly this is what I want to see onto the Pandora. Increasing the good standard Battery time even more with underclocking. Nearly all GP2X Apps could be underclocked IF they are ported for the Pandora and IF the coders optimize them. ^_^

 

[kloplop321]

yeah, I think it would be able to be done easily by a small process running in the kernel in the O/S, unless the processor knows what's going on, hardware would be much better for it though

 

[Chip]

Is it determined by application? Like, load up a genesis emulator, and the program says to downclock to the point where it is just able to run at full speed, saving battery?

Or is it a more inherent feature? where, by default it checks how much the proc is pushing and ajusts accordingly?

The clock speed can be set by an application or by the user. The manual adjustment may be built into the default UI, but even if it isn't there will certainly be a utility for it.

For the most part you will not have to mess with the clock speed at all. Any halfway decent programmer will have his software set it at the lowest optimum value to conserve battery life. That's the nice thing about standardized hardware - every Pandora will be able to run X program at full speed at Y MHz. If the program automatically sets the clock to Y (as it should), then there's no need to fiddle with it.

 

[TaG]

This may be a dumb question....

If an app sets the minimum clock speed and say underclocks to 200Mhz, what would happen if you had something else running in the background, eg music player or IM or whatever? I'm guessing that you might need to manually up the clock speed? Or are any apps capable of adjusting for that sort of thing?

 

[anexanhume]

It all comes down to application privileges in that case.

The easy answer is only run one app at a time. It's a umpc, not a desktop, sheesh :lol:

 

[bigtruck]

Wait, so are all applications going to have to set the clockspeed manually? I was under the impression there would be something similar to cpufreqd that could scale clockspeed dynamically. I'm probably going to have mpd running in the background while I play games, as well as do other multitasking stuff. I'd certainly hope the frequency scaling isn't quite so simplistic.

 

[MilanC]

Asked about all that in another thread... there will be standard sysfs cpufreq interface. Probably "conservative" or "ondemand" as default cpufreq governor. So automatically clocks up when needed
To save as much battery power as possible, you can set up_threshold to 98 (%CPU usage) and down_threshold to something above 50. [ for example 70 if there's a 20% difference between the two clockspeeds, 80 for 15%... ]. I just hope that transition latency is low enough.


[ note: "conservative" and "ondemand" frequency scaling policies are some sort of kernel-based cpufreqd. ]

 

[mindlord]

This may be a dumb question....

If an app sets the minimum clock speed and say underclocks to 200Mhz, what would happen if you had something else running in the background, eg music player or IM or whatever? I'm guessing that you might need to manually up the clock speed? Or are any apps capable of adjusting for that sort of thing?

Apps that would run in the multitasking environment wouldn't (or shouldn't) fiddle with the clock speed. It would be up to the window manager to set the clock speed, or manage the clock speed in a nice way. On my laptop running XFCE I have a nice tray applet called governor that allows me to choose between several cpu speed options ranging from 100% battery chewing 1Ghz speed to miserly 700mhz conserve power speed, "on demand" mode which tries to adjust when cpu load increases or just left governor decide what's best. I suspect for Pandora's multitasking environment this is what will happen too.

In single instance mode, it will be up the the app that's in front, and if you're running something in the background it's going to get pounded on by the app that wants all the attention.

I think people may be under the misconception that they will be able to freely switch applications whether it be the PSX emulator or the Firefox browser, and it doesn't appear to be the case. Some programs will run outside of the X environment, and thus do as they want with the hardware and to hell with background tasks like mp3 players, IM clients, or whatever.

 

[trooper]

I`m pretty sure i heard it works something like speed-stepping on the Pentium processors (though probably more efficient). If a program/app/emulator requires more oomph from the CPU, The processor sense`s this and adjust it`s speed accordingly.

</Disclaimer/>
I`m not a hardware designer/builder, So i could be talking complete Pollox. :rolleyes:

Trooper

 

[bigtruck]

I'm quite relieved to hear it will use cpufreqd. That makes much more sense than requiring all applications to manually set clockspeed.

I think people may be under the misconception that they will be able to freely switch applications whether it be the PSX emulator or the Firefox browser, and it doesn't appear to be the case. Some programs will run outside of the X environment, and thus do as they want with the hardware and to hell with background tasks like mp3 players, IM clients, or whatever.
I hope there are not too many applications that monopolize the hardware. Operating outside of X is one thing (many background tasks would probably not require X anyway), but it would be pretty stupid for example to kill the torrent you're downloading just because you want to play a PSX game.

 

[MilanC]

QUOTE
The processor sense`s this and adjust it`s speed accordingly.

</Disclaimer/>
I`m not a hardware designer/builder, So i could be talking complete Pollox. rolleyes.gif



The *kernel* knows about CPU usage and sets speed.

 

[trooper]

QUOTE
The processor sense`s this and adjust it`s speed accordingly.

</Disclaimer/>
I`m not a hardware designer/builder, So i could be talking complete Pollox. rolleyes.gif



The *kernel* knows about CPU usage and sets speed.

That`s great to hear.

Maybe i should become a hardware designer/builder, Ok, Maybe not.

Trooper

 

[Squidge]

The clock speed can be set by an application or by the user. The manual adjustment may be built into the default UI, but even if it isn't there will certainly be a utility for it.

For the most part you will not have to mess with the clock speed at all. Any halfway decent programmer will have his software set it at the lowest optimum value to conserve battery life.

I hope no software will set or otherwise meddle with the cpu frequency unless you specifically request it. This isn't a single tasking game machine like the GP2X (not technically correct as it runs Linux too, but I'm sure people will agree it's basically single tasking and most emus and game treat it as such) and GP32.

That's the nice thing about standardized hardware - every Pandora will be able to run X program at full speed at Y MHz.

Not necessarily. People will be running different window managers, and different background tasks. Some games/apps/etc will require more or less cpu power (frequency) on different Pandoras depending on what else is running on that machine. The only thing developers can do is say that if it runs full speed on there device, it should run full speed on others if configured appropriately.

 

[anexanhume]

I have no idea what you guys are talking about. I had just planned running it at 900 MHZ all the time whilst spraying CFC's into the air festively and clubbing baby seals.

 

[fusion_power]

Not necessarily. People will be running different window managers, and different background tasks. Some games/apps/etc will require more or less cpu power (frequency) on different Pandoras depending on what else is running on that machine. The only thing developers can do is say that if it runs full speed on there device, it should run full speed on others if configured appropriately.

As long, the Pandora don't forget to underclock, when I close a Power-hungry programm, I'm fine with this. The best way would be to have a little standard application onto the "desktop" or whatever the Pandora will have, where we always can see the current MHz value, something I missed onto the GP2X.

I have no idea what you guys are talking about. I had just planned running it at 900 MHZ all the time whilst spraying CFC's into the air festively and clubbing baby seals.

Do you comming from USA? :lol:

 

[A_SN]

Any halfway decent programmer will have his software set it at the lowest optimum value to conserve battery life.

Tell 95% of GP2X devs

Also, didn't someone establish that idle CPU cycles would be essentially free (as in, no significant drain) and that therefore there would be no need to underclock?

 

[sindbad]

Also, didn't someone establish that idle CPU cycles would be essentially free (as in, no significant drain) and that therefore there would be no need to underclock?
Yes, that is a very useful feature of the omap.

 

[Squidge]

Of course, people have to learn to free those cycles. If you sit there in a loop waiting for a fps timer to expire before drawing the next frame, it's going to run at full speed all the time and eat batteries. People need to learn that if they are not going to do anything useful with processor cycles, to return them to the OS.