Designing The Gp2x's Successor - Hardware Selection Poll

[Epicenter]

For GPH, I think they just drew an SoC out of a hat, honestly. It's made for a DVD player or a digital camera. ARM architecture is probably the ideal choice for power consumption and compatibility reasons though-- compatibility with GP2X, GP32 and PocketPC/Palm software, among other things. Particularly if you're a fan of emulators.

 

[Eso Rimmer]

If the poll should help with selecting cpu for far future device, then there could be much better cpu in that time. So what's the point of making poll like this? I think it's too early.

 

[nemt]

If the poll should help with selecting cpu for far future device, then there could be much better cpu in that time. So what's the point of making poll like this? I think it's too early.

The lifecycle for mobile/embedded processors is different from that of desktop processors.

 

[Epicenter]

For GPH, I think they just drew an SoC out of a hat, honestly. It's made for a DVD player or a digital camera. ARM architecture is probably the ideal choice for power consumption and compatibility reasons though-- compatibility with GP2X, GP32 and PocketPC/Palm software, among other things. Particularly if you're a fan of emulators, as most of the best CPU cores are written for the ARM instruction set, not MIPS.

 

[nemt]

I think you said that already?

 

[Epicenter]

This thread is 18 pages long and spans months ... this is very likely.

 

[Ravnos]

I think he means that you said the same thing twice in 6 minutes. Sort of a delayed double-post.

 

[Cruel]

Screen brightness regulator may be included.
Could it be somehow at hardware level, in that case low brighless->longer battery life? Only that way it would be useful.

 

[Epicenter]

Screen brightness regulator may be included.
Could it be somehow at hardware level, in that case low brighless->longer battery life? Only that way it would be useful.

Versatile backlight power adjustment in software is a common PDA feature and seems to be available on all Samsung SoC based PDAs, so it should be doable with any machine based on one of those. Or it could be done even simpler; lock it in software to 100% and attach a potentiometer to the LEDs' voltage input. However, the backlight should have extremely little influence on batteries, since LEDs sip power. A cold cathode tube like that found in a laptop, or the light mechanisms used on high-end transflective PDA displays, use much MUCH more power, often more than the rest of the system does, but this isn't necessarily the case on all LCD panels.

The bigger battery life benefits should be that the logic voltage level for the whole SoC is lower, and the design is power-optimized to disable or adjust the speed of any unneeded blocks of the SoC when not in full use. The MMSP2 in the GP2X has, unfortunately, terrible power management, uses quite a bit of voltage, and the power subsystem to pass current from the batteries to the MMSP2 and other components is poorly designed, resulting in further waste of power. More careful design could correct that oversight.

 

[icurafu]

For GPH, I think they just drew an SoC out of a hat, honestly. It's made for a DVD player or a digital camera. ARM architecture is probably the ideal choice for power consumption and compatibility reasons though-- compatibility with GP2X, GP32 and PocketPC/Palm software, among other things. Particularly if you're a fan of emulators, as most of the best CPU cores are written for the ARM instruction set, not MIPS.

I beleive the choice came down to the previuos relationship employees had with magiceye.

 

[rixed]

Naive question about a 3D chip :

As many people appear to prefer the next-gen gp2x with a dedicated chip or 3D, this raises the question of the availability of the specifications for this chip : would its programming interface be open or priprietary ? Will we become bound to a proprietary driver, preventing us from modifying the firmware/OS ?

I don't know how this kind of chip come to the market, but I doubt they come with a detailled description of their internals, because it's generally the case with GPU on the PC market.
I think this point deserve some attention.

Sorry if it already have been addressed, Im not following all threads of this forum.

 

[MWeston]

Screen brightness regulator may be included.
Could it be somehow at hardware level, in that case low brighless->longer battery life? Only that way it would be useful.

Versatile backlight power adjustment in software is a common PDA feature and seems to be available on all Samsung SoC based PDAs, so it should be doable with any machine based on one of those. Or it could be done even simpler; lock it in software to 100% and attach a potentiometer to the LEDs' voltage input. However, the backlight should have extremely little influence on batteries, since LEDs sip power. A cold cathode tube like that found in a laptop, or the light mechanisms used on high-end transflective PDA displays, use much MUCH more power, often more than the rest of the system does, but this isn't necessarily the case on all LCD panels.

The bigger battery life benefits should be that the logic voltage level for the whole SoC is lower, and the design is power-optimized to disable or adjust the speed of any unneeded blocks of the SoC when not in full use. The MMSP2 in the GP2X has, unfortunately, terrible power management, uses quite a bit of voltage, and the power subsystem to pass current from the batteries to the MMSP2 and other components is poorly designed, resulting in further waste of power. More careful design could correct that oversight.

Actually backlight control is a huge power saver. A typical 3.5" LCD requires 6 LED's most commonly wired in series. Each one requires a nominal 3.4 volts and a constant current source of 20mA for maximum brightness. Putting that all together yields 20.4V at 20mA. Compound the power drawn by using boost regulators that top out at 86% efficiency at a low input voltage of 2.4V (in the GP2X's case) and you can see where lots of power goes! The backlight accounts for 465mW from the batteries which is about 194mA. PWM of the LED driver on/off signal provides a linear current output (ie. 50% duty = 10mA). If you are laying in bed and really only need the backlight at 35%, you can see how much longer the batteries will last.

Also, I do think the GP2X's power supply is pretty good. I have some pictures of the internals showing a MAXIM-IC MAX1566 on board which is a very efficient chip. It suits this application quite well. Maybe they changed it on later designs? I think the GP2X is just a power hog for other reasons, those being the use of technology "circa 2003"

I agree with you that using lower voltage components is the key. I mean, 3.3V SDRAM vs 1.8V DDR......cmon, no competition

 

[Epicenter]

I beleive the choice came down to the previuos relationship employees had with magiceye.

I wonder when that was. After all, the GP32 had a Samsung SoC.

As many people appear to prefer the next-gen gp2x with a dedicated chip or 3D, this raises the question of the availability of the specifications for this chip : would its programming interface be open or priprietary ? Will we become bound to a proprietary driver, preventing us from modifying the firmware/OS ?

I don't know how this kind of chip come to the market, but I doubt they come with a detailled description of their internals, because it's generally the case with GPU on the PC market.
I think this point deserve some attention.

Well, either SoC uses the well-documented OpenGL-ES API. The Magiceyes part is reasonably documented, the Samsung S3C2460 is extensively documented.

 

[jlebrech]

The gp3x shouldnt have any media card capability, just 2 host usb connection and one B connection. so that you can use usbsticks/wifi/blutooth/keyboard/mice/printers

 

[EvilDragon]

I beleive the choice came down to the previuos relationship employees had with magiceye.

I wonder when that was. After all, the GP32 had a Samsung SoC.

Magiceyes is a partner (or maybe even a daughter company, forgot about that) with Samsung.

 

[Epicenter]

The gp3x shouldnt have any media card capability, just 2 host usb connection and one B connection. so that you can use usbsticks/wifi/blutooth/keyboard/mice/printers

Not being able to use the machine without a big, fat memory stick poking out of it would be deeply aggravating. Plus if you smacked it in mid-operation hard enough it's not that hard to knock some USB memory sticks right off their connector, breaking them out of the jack. And even the smallest common sticks like my Sandisk Cruzer Micro are still quite big when plugging into a device GP2X-sized.

 

[jlebrech]

Well gamepark could release usb sticks that fit into a dock properly. there are plenty of short usb sticks around.

 

[Aninhumer]

Why the hell would you want USBSticks instead of SD cards?
EDIT: The only advantage I can think of is price, and specially designed sticks would cost more...

I can see the point of Host-USB though, but it could just have one port (maybe 2?), and some way to get more if you want them (like the gp2x's EXT port).

BTW, does anyone know how much a touchscreen is likely to add to the price, I'd really like one, but if it's going to cost a lot more...
EDIT: Yay @ likely touchscreen!

 

[Orkie]

Well, you can buy spare DS touchscreens for ~£25, so I expect it would be a *lot* less than that (due to GPH using a standard part, bought in bulk).

 

[pupnik]

Probably a lot more than the ARM11.. I don't really see a reason for hardware much more powerful than an ARM9 around 300 Mhz for gaming applications, though.

Good ... grief...

The ARM926Ej-S is what i've been porting games to for 6 months now and it's old news. The linux pda it's in (Nokia 770 has been out for years and it's about as fast as the gp2x overall.

You can pick one up for $140 now. Problem is no right hand side buttons and a sucky directional pad for gaming.

This is at 250mhz in the OMAP1710 SOC -- /proc/cpuinfo says 125 bogomips. The successor Nokia 800 which is nearing a year in age has the OMAP2420 yielding about 300 bogomips.

Neither of these has the power to run a straight port of snes9x, or even fceu. And you're takling about the lower-power one as a successor to the gp2x. Bwaahaha.

Emulation is the bread and butter of Gamepark Holdings. Not homebrew 3d, not commercial games. If they bring out a barebones device with an ARM A8 cortex, they can deliver a new class of emulation. If they try to go for a do-everything device, they'll probably get trounced by the successor to the Nokia 880.