Pandora''s 3d Graphics

[ljones]

Hello all !

I'm sorry if there have been 9,999 threads on this before(!) but I was just wondering whereabouts does the pandoras' 3D chip fare with regards to the other common (e.g. nVidia) 3D chips out there in terms of speed? I understand that since the pandora is ARM based some things (thinking of Mhz) can't be compared (mainly for the CPU; is it the same for the 3D chip?). From what I've read on these forums, I see Quake 3 mentioned quite a lot but then again, Quake 3 isn't a new game -- first released way back in 1999. So very crudely speaking, would it be right to say the pandoras' 3d chip will perform like (say) a 3-year old nVidia card (I have no idea).

Only reason I ask is that I was thinking once I have my pandora - I was thinking about compiling the software to use 'second life' on the pandora ( http://wiki.secondlife.com/wiki/Get_source_and_compile ) though I'm not sure as I don't know if the pandora would be too slow to run it at all?

ljones

 

[lulzfish]

You'll have some trouble with compiling that, since the Pandora uses OpenGL ES, the cut-down portable flavor of OpenGL.

I don't know where the SGX stands in vertex and polygon rates, but it's probably comparable to a 3 or 4 year old graphics card [somebody said it was just above the original Xbox] but I think the shaders are much more advanced.

 

[fischju2000]

I think there was a comparison a while back to the Nvidia 6600, the SGX is faster in some ways and slower in others.

 

[borgqueenx]

heh i made a topic like this some time ago. but compara the pandora with a psp, ds, nintendo 64, and netbook, all in one, in a small size.

 

[nubie]

I think there was a comparison a while back to the Nvidia 6600, the SGX is faster in some ways and slower in others.

But which 6600? The range of '6600' cards go from a rebadged 6200 up to the ddr3 6600GT, so that is still not a good comparison.


As far as I am concerned the hardware specs don't have much to do with anything unless the software is well written and the whole system is balanced (Enough CPU and mem bandwidth for the video to really work well.)

If you want to see what it is capable of there are plenty of vids on youtube:

CODE
http://www.youtube.com/watch?v=3ToYOgP9f9U


just search for Powervr sgx

 

[d3v]

Hello all !

I'm sorry if there have been 9,999 threads on this before(!) but I was just wondering whereabouts does the pandoras' 3D chip fare with regards to the other common (e.g. nVidia) 3D chips out there in terms of speed? I understand that since the pandora is ARM based some things (thinking of Mhz) can't be compared (mainly for the CPU; is it the same for the 3D chip?). From what I've read on these forums, I see Quake 3 mentioned quite a lot but then again, Quake 3 isn't a new game -- first released way back in 1999. So very crudely speaking, would it be right to say the pandoras' 3d chip will perform like (say) a 3-year old nVidia card (I have no idea).

Only reason I ask is that I was thinking once I have my pandora - I was thinking about compiling the software to use 'second life' on the pandora ( http://wiki.secondlife.com/wiki/Get_source_and_compile ) though I'm not sure as I don't know if the pandora would be too slow to run it at all?

ljones

if you're wishing to compare the soc sgx incarnation found in pandora to modern desktop cards (such as those by nvidia) that's a tad unfair. besides, i don't think a spec comparison will quite work, as powervr h/w does things differently, culling a lot of unnecessary work and getting many better results that would be expected of a similar spec'd chip
if you wish to compare it to competing mobile chips then that's also unfair - on everything else! [except perhaps other slightly more powerful sgx incarnations] LOL

 

[Exophase]

You'll have some trouble with compiling that, since the Pandora uses OpenGL ES, the cut-down portable flavor of OpenGL.

I don't know where the SGX stands in vertex and polygon rates, but it's probably comparable to a 3 or 4 year old graphics card [somebody said it was just above the original Xbox] but I think the shaders are much more advanced.



XBox is 7.5 years old. I'm very skeptical that Pandora's GPU is competitive with a typical 3-4 year old card released by nVidia (not counting bottom of the barrel budget cards)

 

[hch]

i have tried several times to google for the low-level specs of the GPU alas i never really found them. but anyways, there is enough hardware info that i think i can make a reasonable guess.

first, the memory is DDR-333 (shared) with a total bandwidth of 2.6GB/s. for many applications, this is the limiting factor anyways. then, the wikipedia page mentions a poly fill rate of 14MPoly/s (and i guess the pixel fill rate will be around 0.5GP/s). this roughly the ball park of a GeForce 6100 or ati x200 igp.

on the other hand, it seems that the hardware in principle it is capable of shader model 4.1, directX10.1 and full opengl 3.0 (as confirmed by craig), which is quite a bit more advanced than the comparison cards. still, even the lowest end igps on the cheapest of todays netbooks are superior in brute force pixel pushing (provided the drivers can make use of it).

edit: typo

 

[AireTamStorm]

Not maintained:

CODE
http://docs.google.com/Doc?id=df9b28k5_17fw5b27fw

 

[darkblu]

i have tried several times to google for the low-level specs of the GPU alas i never really found them. but anyways, there is enough hardware info that i think i can make a reasonable guess.

first, the memory is DDR-333 (shared) with a total bandwidth of 2.6GB/s. for many applications, this is the limiting factor anyways. then, the wikipedia page mentions a ply fill rate of 14MPoly/s (and i guess the pixel fill rate will be around 0.5GP/s). this roughly the ball park of a GeForce 6100 or ati x200 igp.

on the other hand, it seems that the hardware in principle it is capable of shader model 4.1, directX10.1 and full opengl 2.0 (as confirmed by craig), which is quite a bit more advanced than the comparison cards. still, even the lowest end igps on the cheapest of todays netbooks are superior in brute force pixel pushing (provided the drivers can make use of it).

don't mind me too much, but:

any hardware capable of es2.x is capable of full gl2.x - it is a matter of driver availability.

"poly/s" is a measure of transform rate, fillrate is a measure of producing pixels ("pixel/s").

/language police


threads like this one invariably remind me of one story i'll share:

a guys was at this party many a year ago, and was having a good time, enjoying the drinks and the girls, until this unfamiliar guy pops up, persistently trying to strike up a conversation with everybody around, assuming the geeky angle (as it was somewhat of a hackers party). after boasting with pc specs and other geeks-must-be-impressed-of-such-stuff things, he approaches our guy with the question 'hey, dude, what is your VGA?' (as at that time the VGA and derivatives were the top of the food chain). our guy, being the rather eloquent type, answers:

'suuuuper.'

 

[hch]

don't mind me too much, but:

any hardware capable of es2.x is capable of full gl2.x - it is a matter of driver availability.

3.0 - sorry for the typo

"poly/s" is a measure of transform rate, fillrate is a measure of producing pixels ("pixel/s").

/language police

you could let the world profit from your knowledge and fix the wikipedia pages.

 

[Exophase]

a guys was at this party many a year ago, and was having a good time, enjoying the drinks and the girls, until this unfamiliar guy pops up, persistently trying to strike up a conversation with everybody around, assuming the geeky angle (as it was somewhat of a hackers party). after boasting with pc specs and other geeks-must-be-impressed-of-such-stuff things, he approaches our guy with the question 'hey, dude, what is your VGA?' (as at that time the VGA and derivatives were the top of the food chain). our guy, being the rather eloquent type, answers:

'suuuuper.'

<darkblu> this one time we were gathered at the town square and isaac brought a bale of cotton
<darkblu> he was showing it off to all of the townspeople
<darkblu> he asked luther, "hey sir, how do you process your cotten?"
<darkblu> luther, being the smug asshole that he is, responded
<darkblu> "ginned"
<darkblu> i'm old

 

[darkblu]

you could let the world profit from your knowledge and fix the wikipedia pages.

bah, people should read more litera^H^H^H pdfs and less wikipedia, and there's no fixin to that.

<darkblu> this one time we were gathered at the town square and isaac brought a bale of cotton

naah, the one you refer to happened many years later after the svga one. apropos, does anybody need a 13h intializaiton routine? : )

 

[White Flame]

Fillrates and such really don't map well between standard PC framebuffer filling, and the PowerVR tile rendering, which afaik can do hidden surface elimination at the polygon level instead of per-pixel. The SGX could theoretically get away with a much slower fillrate and still get equivalent frame rates.

 

[WizardStan]

apropos, does anybody need a 13h intializaiton routine? : )
No thanks. Still got my original graphics library kicking around somewhere, with both 2D and flat shaded 3D polygon routines. I upgraded it to use VESA eventually, but then Windows95 came along and the real mode gaming sector basically died. It was tragic.

 

[BackAssward]

apropos, does anybody need a 13h intializaiton routine? : )
No thanks. Still got my original graphics library kicking around somewhere, with both 2D and flat shaded 3D polygon routines. I upgraded it to use VESA eventually, but then Windows95 came along and the real mode gaming sector basically died. It was tragic.

I still remember writing to the VGA memory directly. I loved those old 64k people, and tried to do the same...

 

[MrPoletski]

Fillrates and such really don't map well between standard PC framebuffer filling, and the PowerVR tile rendering, which afaik can do hidden surface elimination at the polygon level instead of per-pixel. The SGX could theoretically get away with a much slower fillrate and still get equivalent frame rates.

The theory behind PowerVR is simple.

A normal rasteriser (pretty much every 3D chip ever) will be fed triangles as their data is calculated by the CPU. It will draw this triangle and then do a depth test to see if the pixels it rendered should overwrite or be superceded by information currently in the frame buffer.

It's a triangle production line, you throw traingles in one end and they come out the other. This might mean that triangles are rendered and then overwritten by triangles closer to the camera, or it might mean that triangle data is calculated but not written because something else is already closer. This wasted effort is called overdraw.

PowerVR changes this by collecting ALL the traingle datafor an extire scene (co-incidently, while it is doing this it is drawing the previous frame from the data it collected last time). When you have ALL of the scene data collated together it allows you to do some advanced hardware sorting and tricks.

Now aside from a whole host of neat tricks that can be done, the real saviour is the fact that overdraw can be totally eliminated on a per-pixel level (sub pixel level with AA turned on). This means slashing memory bandwidth and shader workloads. Overdraw back in the day (when I was shouting about PC add in boards based on PowerVR tech) around the quake 3 era actually, overdraw back then was about 3x. As in 3x as much work is done than is needed, this extra work is not done on PowerVR.

check this out:

http://www.anandtech.com/showdoc.aspx?i=1435

anads review of the KYRO II. For reference this was a 2 piped fixed function rasteriser using powerVR technology. It's clock speed was 166Mhz synced to its 128bit SDR RAM.

here you can see the KYRO II bitch slapping the Geforce GTS ultra (which was over twice the price at the time) in a few games.

 

[hedwards]

anads review of the KYRO II. For reference this was a 2 piped fixed function rasteriser using powerVR technology. It's clock speed was 166Mhz synced to its 128bit SDR RAM.

here you can see the KYRO II bitch slapping the Geforce GTS ultra (which was over twice the price at the time) in a few games.

I do wonder what would have happened had they not made such stupid business decisions. I owned one of the first cards and it wasn't until years later that the kyro II came out. That whole idea to 1) do the dreamcast hardware and 2) delay the pc successor was a really huge mistake.

I had one of the original chips and it did a pretty good job at a low cost.

 

[Exophase]

[quote name='White Flame'
anads review of the KYRO II. For reference this was a 2 piped fixed function rasteriser using powerVR technology. It's clock speed was 166Mhz synced to its 128bit SDR RAM.




Worth noting: Pandora's SGX is also two pipe, can only run up to 110MHz, and is attached to mobile DDR RAM that's effectively much slower than what you listed. Maybe Kyro II "bitch slapped" GeForce 2 (in only SOME games..) but people are expecting Pandora's SGX to beat Xbox which is better than GeForce 3, hell, people in this thread are expecting it to beat chips much newer than that. Yeah, SGX has shaders and other architectural improvements but how far can that really take it beyond its predecessors?

 

[Calmatory]

This is one of the threads I wish I had never opened.

Few words: People get to know the hardware business. Get to know the old cards, their specs, their capabilities and features. Then you will understand that having anything like "GeForce 6 series" inside Pandora with Pandora's battery and power draw laughable claim. Performance/watt ratio would have to blast anything in the market for next 2-3 years at least. Good luck trying to beat Nvidia/AMD/Intel at that.

Yeah, I am hardware enthusiast.