Nintendo DS GPU

[see colon]

Maybe it's like flash-RAM that can be very large but also very slow (compared to real RAM). I believe flash memory is doing some sort of bank switching and is using a pretty narrow bus to get the data out of the die.

it's not just "like flash-RAM", it is flash-RAM. NDS games are flash, and it's flash's cheap price (compared to the traditional ROM carts nintendo used for gameboy) that allows them to price DS games comparable to GBA games even though they are larger in size (data-wise). flash memory is great because it offers an affordable price, decent storage size, pretty low access times, quick manufacturing, and jog-proof performance. so it offers a nice balance between the older rom carts and the current optical disk standards.

what the DS cards lack is the ability to have custom hardware in the cart like GB games have in the past. like all of those GBC games with rumble, motion sensative games like kirby tilt-n-tumble, and photosensative games like baktai. i suspect that was a pretty big incentive for nintendo to keep a cart port on the DS, beyond the obvious backwards compatability.

 

[Guden Oden]

it is flash-RAM.

How do you know for sure? "Internet knowledge" doesn't really cut it as an authorative source...

what the DS cards lack is the ability to have custom hardware in the cart like GB games have in the past.

I don't think that's a fact at all. It's possible to both read and write to the cart, hence custom hardware really should be possible. The real problem would be fitting it inside that tiny space allowed, that's all.

 

[Tagrineth]

Just curious, but how did u know this?

And if u somehow have the 'inside track', how are the loadtimes in this game coming along? Are they being improved?

I'm not on any inside track this time around. =) It's nothing more complicated than an interview in a recent Nintendo Power magazine.

 

[I.S.T.]

question:

How is the overall power on the DS' GPU? Is it comprable to, say, a GF2MX?

 

[Guden Oden]

No, the DS is much weaker than even a GF2 MX, both when it comes to features and most importantly performance. Then again, the entire DS draws like 2.5W, which is maybe 1/10th of the GF2 MX.

 

[Murakami]

Is the DS faster than a PS1 and features richer overall?

 

[Megadrive1988]

question:

How is the overall power on the DS' GPU? Is it comprable to, say, a GF2MX?

the power of DS' 3D engine is not even remotely close to a GeForce2 MX. DS's graphics are not even close to that of a TNT2 or even a TNT. if you're going to compare to an Nvidia chip, DS is closer to the Riva 128 from 1997, maybe even less.

really, it's not even on par with the original Voodoo Graphics.

remember DS can display about 120,000 textured polygons with things turned on. that's something like Rendition Verite level of performance.

 

[I.S.T.]

Thanks, all. I havnt' had much of a chance to find info on it(Don't know where to look...), so I had no idea.

games are decent looking for such a weak system.

 

[Megadrive1988]

Thanks, all. I havnt' had much of a chance to find info on it(Don't know where to look...), so I had no idea.

games are decent looking for such a weak system.

yeah, many DS games look pretty nice. it's still a large leap up in power from the GBA, and very comparable to the PS1.

 

[Guden Oden]

Is the DS faster than a PS1 and features richer overall?

Likely richer in features, yes. Not sure about performance tho; PS might have more fillrate, I'm not sure. Then again, PS didn't have any Z-buffer support which does save memory and performance at the cost of visual integrity, DS seems to have that at least since I've not seen any game so far with the kind of crazy flickering polygons that was the trademark of PS-era console graphics. DS also has much better polygon clipping it seems, since on the PS if a poly stuck out of the screen it wouldn't get drawn period. This led to lots of problems, games usually got around it by subdividing the offending polys, but there were always the odd case where that didn't work fully and polys would disappear anyway.

Twisted Metal was infamous in that regard as I recall, it also used lots of very large polys, thus causing textures to bend and twist in a most annoying manner due to the PS's lack of perspective correction.

 

[Murakami]

Likely richer in features, yes. Not sure about performance tho; PS might have more fillrate, I'm not sure. Then again, PS didn't have any Z-buffer support which does save memory and performance at the cost of visual integrity, DS seems to have that at least since I've not seen any game so far with the kind of crazy flickering polygons that was the trademark of PS-era console graphics. DS also has much better polygon clipping it seems, since on the PS if a poly stuck out of the screen it wouldn't get drawn period. This led to lots of problems, games usually got around it by subdividing the offending polys, but there were always the odd case where that didn't work fully and polys would disappear anyway.

Twisted Metal was infamous in that regard as I recall, it also used lots of very large polys, thus causing textures to bend and twist in a most annoying manner due to the PS's lack of perspective correction.

Maybe PS1 has more fillrate and can draw more poly/sec (without Z buffer and perspective correction, i know it), but DS has twice the ram and its main cpu clock is nearly double...

 

[Guden Oden]

Clockspeed schmockspeed.

While the R3300A was hardly any kind of a monster chip, I rather doubt the ARM9 really is much better, and as for memory, the PS actually had a bit over 3.5MB memory total, though divided up into four separate pools. It's not really 2x difference between the two; remember that it's got 2MB main RAM, 1MB video RAM, 512k sound RAM, and then a tiny 32k CD buffer. While the DS has 4MB in a single chunk (which should be simpler and more flexible), as it turns out the hardware accesses that memory through a ton of different banks meaning things are at least as messy as on the PS with its physically separate pools...

Besides, since it's just one piece of RAM, it means bandwidth has to be shared between ARM7 and ARM9 CPUs, sound and the 2D/3D display processors. We also don't know how much b/w the DS has to begin with... PS likely has considerably more aggregate system bandwidth.

Then again, DS really does have ENOUGH "oomph" for what it's trying to accomplish. Though lumpy and old-fashioned on the inside, it presents a rather slick image to the player. And, it accomplishes everything within a 2.3W power budget. Damn neat I have to say!

 

[Murakami]

Guden, are you sure that the DS has only 4 mb shared memory? I believed that ds memory configuration is:
Main Memory: 4 MB
ARM9/ARM7 Shared - 32KB
ARM7 Internal RAM - 64 KB
VRAM - 656 KB

About DS 3D graphics engine, i found these specs:
Maximum 4 million vertex per second geometric transformation
30 million pixels per second maximum fill rate
120,000 polygons per second maximum

And PS1 related:
3D Graphical Capability
* Rendered in hardware - Upto 360K polygon/sec.
Polygon drawing rates
- For a 50 Pixel Triangle (10 X 10)

+------------+-------------------+
|   Texture  |  Shading          | 
|   Mapping  |                   |
+--------------------------------+
|            | Flat    | Gourard |
+------------+---------+---------+
|    OFF     | 360K    | 200K    |
+------------+---------+---------+
|    ON      |         |         | 
|   4 bit    | 200K    | 140K    |
|   8 bit    | 100K    |         |
|   15 bit   | 60K     |         |
+------------+---------+---------+
| Polygons / Sec

 

[Shifty Geezer]

+------------+-------------------+
|   Texture  |  Shading          | 
|   Mapping  |                   |
+--------------------------------+
|            | Flat    | Gourard |
+------------+---------+---------+
|    OFF     | 360K    | 200K    |
+------------+---------+---------+
|    ON      |         |         | 
|   4 bit    | 200K    | 140K    |
|   8 bit    | 100K    |         |
|   15 bit   | 60K     |         |
+------------+---------+---------+
| Polygons / Sec

Fixed. Edit in a fixed font-size editor like Notepad, then copy and paste using <CODE> tags (obviously changing <> for [])

 

[Guden Oden]

Dude, chill okay? Seriously.

As for the 4MB, it's the only hard spec I've been able to find, official or otherwise. While you might see 656kB video memory figure somewhere, I've not been able to verify FOR SURE that these 656kBs aren't simply taken as a bite out of the main 4MB pool. I'm thus assuming for now that 4MB is the amount of physical RAM in the DS (barring any possible legacy memory from the GBA, like the integrated Arm7 64k you mentioned, which is kind of insignificant really).

As for the 4mvert/30mpix figures - have you ever seen any 3D game on the DS that comes even close to these levels of performance? Because I bloody well haven't! Metroid Prime Hunters runs at 30fps at best on a tiny resolution screen (smaller than original PS), using very coarse geometry.

 

[Murakami]

Fixed. Edit in a fixed font-size editor like Notepad, then copy and paste using <CODE> tags (obviously changing <> for [])

Thanks for the tip!

 

[Murakami]

Dude, chill okay? Seriously.

Guden, are you joking or what? Don't you like smiles? What's your problem?

I like using smiles: that's all.

 

[Corwin_B]

As for the 4mvert/30mpix figures - have you ever seen any 3D game on the DS that comes even close to these levels of performance? Because I bloody well haven't! Metroid Prime Hunters runs at 30fps at best on a tiny resolution screen (smaller than original PS), using very coarse geometry.

The bottleneck is the 120K polys/sec (that's a display limit, IIRC), which in turn reduces to an average of 2000 polys per frame at 60FPS, or 4000 polys per frame at 30FPS.

The developers of Mech Assault DS have an interesting blog on IGN where they discuss some of the limitations and trade-offs involved into making a 3D DS game : http://blogs.ign.com/MechAssaultDS/

“What happens when you go over the 2000 poly/frame limit?â€

BBE: Basically, when you go over the limit, polys stop drawing and you won’t always know which ones those are. The real kicker is that if 1 poly is over limit, it takes out any polys that share vertices with it too – like a bad chain reaction. There’s always the possibility of introducing bugs when you’re straining the hardware too much so it’s just best to keep an eye on the poly count as you go through levels to ensure you’re always under your limits.

 

[Fafalada]

Likely richer in features, yes.

DS GPU is funny in that way. It actually has a couple features that were not seen until GF1 (and at least one that GF1 didn't have ), at any rate just the fact it has hw clipping and texture compression is enough to put it beyond PS1 era graphics hw.

As for transform rate - think of it the same way as 360/PS3 where you can transform in order of 10Bilion polys/sec, but you'll be lucky to draw 2% of that.

 

[Blade]

The DS is not only beyond the PS1 in horsepower, but probably above the N64 in many regards as well.

A good example would be Mario Kart DS. 60fps and doing a lot more on-screen than the 30fps MK64, including the polygonal (albeit low-poly) racers that Nintendo wanted to use in MK64 but couldn't due to technical limitations.