Off To Korea, Gpx2 Awaits!


A couple of people (including myself) were talking to Craig last night whilst he was on IRC, and it certainly seems that (from what he's said) Snes, GBA and Amiga will be possible, as long as it's done properly. Ie, a straight port isn't going to work, but a version made for the gpx2 should work quite nicely. Note that this is not a quote from Craig, it's just what I believe is possible from what he said.

A couple of other things no doubt will make devvers happy too :)
 
Squidge posted on Aug 28 2005 at 10:20 AM said:
A couple of people (including myself) were talking to Craig last night whilst he was on IRC, and it certainly seems that (from what he's said) Snes, GBA and Amiga will be possible, as long as it's done properly. Ie, a straight port isn't going to work, but a version made for the gpx2 should work quite nicely. Note that this is not a quote from Craig, it's just what I believe is possible from what he said.

A couple of other things no doubt will make devvers happy too :)
are you happy with what youve seen/heard?
 
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Squidge posted on Aug 28 2005 at 06:20 AM said:
A couple of people (including myself) were talking to Craig last night whilst he was on IRC, and it certainly seems that (from what he's said) Snes, GBA and Amiga will be possible, as long as it's done properly. Ie, a straight port isn't going to work, but a version made for the gpx2 should work quite nicely. Note that this is not a quote from Craig, it's just what I believe is possible from what he said.

A couple of other things no doubt will make devvers happy too :)

See, thats the rub ;) I keep bringing it up, but why not beat a dead horse?

Two cores is cool (so devs may be interested), and with Linux behind it likely more devs will pile on board (ie: the Slashdot community et al :p) However, two cores means much more work in order to get some effectiveness out of them..

ie: 2 * 200Mhz would likely at best work out to 350MHz -- overhead for talking between CPUs, and while one CPU waits for the other etc. Further, in practice, it cna often work out much less as one CPU is master while the other is delegated to just specific thing slike blits or whatever..

If code is very carefully create to work on both CPUs for this device, it coul rock.. get the full 400MHz out of it. But we all know thats not going to happen quickly or maybe at all, so most apps will be limited to 200MHz, or maybe toss a few things over to the otehr.. so maybe feel like 250.

(Lets hope they overclock ;)

So I'd say it would be better to have 400MHz for them both, or a single 400.. over a dual core or the like. It just makes it harder to dev for, and theres not enough devs to go around.

Examples:

Does Fenix handle multi-threading across CPUs? Hope so.. we've got a ot of Fenix coders here now, and if Fenix is single-thread, then it won't get any advantage.

ScummVM -- thats a huge project; does it handle multiple threads already now? If not, it would likely be a _tonne_ of work to make it do so. So if not, it'll likely remain at 200MHz effective speed.

Emus -- most of the GP32 emus are ports.. not written by the porters. They're all monolithic.. decode, emulate, render, repeat. So most just do a quick port and thats that.. it'd take 'some work' to use the dual cores. Fortunately, do to the separaiton of components, they may well dual core pretty easily, and if someone actually is doing significant work on it they could_really_ use the dual core.

ie: CaSTaway .. mostly CPU emulation heavy, but the video rendering coudl easily be dispatched to second CPU; this would be an example of the 80/20 -- one CPU doing 80% of the work, and the other doing 20% (sound and video emulation); however, this would be all CaSTaway needs to go full speed no lag no problem.

Amiga could be harder, bu with all those custom chips, it coudl be possible with good timing to spread them around.. however, the timing might be difficult to do and also get speed up..

Snes9x .. the rendering of the display is a heavy part of the speed here, so it could really help to have a seocnd CPU; at render time, take a snapshot of state and then render it while the emulaton continues? May work out well.. or maybe suck. Coudl really use a real graphics GPU here.

So.. many apps will get no benefit from a unused second CPU; some apps may get tuned and take some small advantage. But a few apps, written carefully for GP32, could go nuts and do great things. Just takes more work.

So thats why I say.. one chip makes it 'easier', so thats the way to go; on a professional machine adopted by thousands, dual core would actually get used right :)

Still, we're getting dual core.. so devs better get reading those specs ;)

jeff
 
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The whole 2*200mhz = 1 * 350mhz is misleading

While that is essentially true if both cores are the same, there are a few bonuses, one being that if one particular function is a CPU time hog, you've got two cores so it won't bring everything to a halt while this is being carried out (even if you code a multi threaded piece of software, an infinate loop or overly intensive piece of code can bring things to a halt on a regular CPU).

But there's the fact that the cores are not the same. Each core is optimised for different purposes. The video core will very likely perform graphics functions faster than the general core for instance. If you optimise the code to take advantage of this, you'll probably get more performance than out of a single 400mhz CPU.

Multi-threaded programming is tricky but it's becoming as important an ability to learn as true OOP is, especially since pretty much all desktop PCs and consoles are moving to multi-core.
 
Don't forget about things like cache and bus structure. A core that is dedicated to a single purpose needs less thread swapping, memory reads are more aligned etc. But I agree that most applications can't simply be subjected to a 50/50 functional decomposition. But we'll have to see. The most important news for me is the fact that we can boot another OS from SD. This means basically that we can run custom linux distributions, wich opens the door for a lot of fun I think :)
 
yeah, I do like the idea of running a super stripped down kernel or even alternate OS (BSD!) -- hell, if they play their cards right, maybe they'll be selling the device to universities for teaching Minix on :)

jeff
 
I WANT A GPX2....AND I WANT IT NOW..Pretty please with sugar on top.
 
I WANT REESY TO HAVE A GPX2....AND I WANT HIM TO HAVE IT NOW..Pretty please with sugar on top.
 
moz posted on Aug 28 2005 at 02:28 PM said:
are you happy with what youve seen/heard?

Oh yes :) I'm just hoping my estimations and assumptions are correct.

Skeezix: I've noticed some people talk about multithreaded fenix, but I'm not sure if that means the interpreter is multithreaded, or whether it just supports multithreaded commands...
 
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skeezix posted on Aug 28 2005 at 02:20 PM said:
So I'd say it would be better to have 400MHz for them both, or a single 400.. over a dual core or the like. It just makes it harder to dev for, and theres not enough devs to go around.

...Still, we're getting dual core.. so devs better get reading those specs ;)

jeff


Well yeah that was my concern that the dual core would make coding difficult. I was dissapointed about 200 MHz too. Even if only one core was used though and the second as a fancy blitter/screen buffer it is still faster than a GP32 and CaSTaway does run great on a 166 MHz GP32. Now if you integrated Reesy's and Notaz's new fixed cyclone core into Castaway it would be even faster still. Then add into the mix that the GPx2 has *64 MB* of RAM and it gives even more possibilities. So for stuff on the GP32 now those emus will still run better on the GPx2.

Stuff like Amiga, SNES, and GBA sounds like a pain though. Still doable for coders that like hacking around with multiple CPUs. If the second ARM can be turned into a GPU emulator while the main one emulated the main CPU and they communicate well it would work out well. Craig makes it sound real good but you do have to take into consideration that he wants to make it sound good to sell more systems. Is he over hyping it? I guess we will see when released.

Also how do you like coding for the PSP? I notice that you are getting into PSP developement pretty heavy. That has multiple CPUs too. Is that hard to do?
 
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You know what - look at a lot of new hardware lately - from game consoles to PC's - multiple CPU cores are becoming pretty common.

So it's not a bad thing for devs to start cutting their teeth on coding for multiple CPU cores. It's actually good experience if they're planning to code for some of the upcoming hardware in the future.

Lastly - since it now sounds like the 2nd core IS fully programmable, can we all be a LITTLE happy please? Alright, so it will take some work to get the most out of the GPX2 - but at some point some brilliant devs will release source code that shows how to make good use of the 2nd CPU. And then other devs will be abe to adapt those techniques to their own work. It may take a year for this to all solidify, but once done this little system could really fly. At the VERY LEAST it's faster than the Zodiac and the GP32, and there were some damn good emus on both. Plus it has a ton of memory, perfect controls IMO, a good sized screen, SD cards, and is Linux based.

All for less than $200.

IMO this is a device to celebrate and embrace, not to whine over what it doesn't have. What other company would make something like this - a dveice aimed squarely at the emu/homebrew crowd? NOBODY! :p

Thank you GPH. :)
 
Less than $200 is pretty good; the GP32 cost me more than that :)

jeff

DaveC -- I've barely had time to muck with the PSP besides crashing many of its components individually in all sorts of neat ways ;) I've done multiprocessor coding for years so its not a concern of mine.. but I've not done OpenGL or related before, so screwing with the PSP is helping me pick up some of the lingo. Had to find out what Texture Swizzling was for instance, and OpenGL scissor-filters, and such..
 
Huxley posted on Aug 28 2005 at 11:43 PM said:
Reesy posted on Aug 28 2005 at 03:20 PM said:
I WANT A GPX2....AND I WANT IT NOW..Pretty please with sugar on top.

Yeah...what he said. I don't even care if this thing is called GPenis anymore, I WANT ONE!

LOL! :lol:

GPenis... OMG. I hope not. I'd still buy it, but I'd have to invest in getting a nice custom label made.
 
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nah, i don't think GPH would do that. (....) would they? :unsure:

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gpx2.com? Ah, owned by someone at gamepark.

Sticking with gp32x.de I hope, and not opening another? :)

jeff
 
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