Toshiba TC35285XBG

[Rob Evans]

http://www.toshiba.co.jp/about/press/2004_02/pr2301.htm

Another mobile phone chip with 3D.

"OpenGL-ES is fully supported as the graphic API"

"Able to process 3.5-million vertices a second and 125-million pixels a second."

Sounds rather like the MBX Lite!

 

[moichi]

Toshiba says "3D Graphics Function are based on our experience on Playstation".
http://www.semicon.toshiba.co.jp/prd/ics/mpeg/mpeg_top.html

 

[Nappe1]

hmmh... it has 2.5 Megabytes of eDRAM (20MBit) made in 130 nm process. eDRAM processes have come a long way pretty quickly.

well, at least the market segment has some really tough competition soon:
- Toshiba
- ATI
- nVIDIA
- Bitboys
- Mitsubishi
- PowerVR

any others?

 

[ram]

any others?

Sanshin Electronics: http://www.gshark.com

 

[Ailuros]

I wouldn't count Sony out either for the foreseeable future.

 

[Luminescent]

I wonder if this chip has anything to do with the renderer inside the Sony PSP?

 

[moichi]

Sony published one paper about 3d processor for mobile-phone at ISSCC 2004(paper number 13.4).
Spec is 4.7Mvert/s and 600Mtexel/s.

 

[Rob Evans]

Is it just coincidence that the performance of the Toshiba part is almost identical to the MBX Lite?

Figures from http://www.arm.com/pdfs/MBX 3D.pdf (0.13um)

Speed > 120MHz
Fill Rate 120million pixels/sec
Rendering 1 million triangles/sec

Toshiba figures from http://www.toshiba.co.jp/about/press/2004_02/pr2301.htm

Speed 125MHz
Fill Rate 125 million pixels/sec
Rendering 3.5 million vertices/sec

 

[Nappe1]

Is it just coincidence that the performance of the Toshiba part is almost identical to the MBX Lite?

Figures from http://www.arm.com/pdfs/MBX 3D.pdf (0.13um)

Speed > 120MHz
Fill Rate 120million pixels/sec
Rendering 1 million triangles/sec

Toshiba figures from http://www.toshiba.co.jp/about/press/2004_02/pr2301.htm

Speed 125MHz
Fill Rate 125 million pixels/sec
Rendering 3.5 million vertices/sec

Maybe that's the most wanted speed on market right now. Both chips are based on so different architechtures that those numbers do not mean much. it's the real speed that end user sees. (Both architechtures have good and bad sides.)

anyways, interesting to see that Toshiba states Vertice speed instead of triangle speed. Support of other primitives too perhaps?

 

[PC-Engine]

MBX has much lower power consumption though.

 

[Ailuros]

Is it just coincidence that the performance of the Toshiba part is almost identical to the MBX Lite?

Figures from http://www.arm.com/pdfs/MBX 3D.pdf (0.13um)

Speed > 120MHz
Fill Rate 120million pixels/sec
Rendering 1 million triangles/sec

Toshiba figures from http://www.toshiba.co.jp/about/press/2004_02/pr2301.htm

Speed 125MHz
Fill Rate 125 million pixels/sec
Rendering 3.5 million vertices/sec

That flyer has slightly different numbers:

http://www.arm.com/miscPDFs/1643.pdf

MBX R-S @130nm

300K gates
Power: 0.7mW/MHz
120MHz
1.5Mtris/sec
240M Pixels/s

But Nappe is right; paper specs are just that paper specs. What comes out at the other end will be more important when first products will be available for sale.

 

[PC-Engine]

Notice the 3D graphics block from the Toshiba part consumes twice as much power as MBX.

 

[Ailuros]

MBX has much lower power consumption though.

Less than half.

 

[Rob Evans]

Notice the 3D graphics block from the Toshiba part consumes twice as much power as MBX.

Are you sure it uses more power? The Toshiba figures include the power consumed by the embedded DRAM.

Does anyone know how much power 20Mbit embedded DRAM consumes at 125MHz? It would be very interesting if the answer was 'around 100mW'!

 

[PC-Engine]

As a complete solution it still draws more power because it would still need additional main RAM. I think MBX can use main RAM as it's texture memory so it doesn't need a separate pool of memory.

 

[Nappe1]

As a complete solution it still draws more power because it would still need additional main RAM. I think MBX can use main RAM as it's texture memory so it doesn't need a separate pool of memory.

well, that depends... 20MBit is actually 2.5 Megabytes of RAM. if you have 320x240 screen, it will take (320x240x2x2)+(320x240x2)=450 Kilobytes of memory. (16 bit Z, 16 bit colors and double bufferin) So, there's still over 2 Megabytes left for textures, which is about the same as 4MB Voodoo 1 had.

does it support texture compression? if yes, then it is even more likely that it does not need additional memory for graphics. Or external memory can be remarkably slower, if only front buffer is held in there. If it is tiled back buffer implementation, only tile being rendered has to be in eDRAM, while rest of back buffer is in external memory, need of eDRAM is much smaller and while external memory is needed, it has to be able to deliver only around 10% of bandwidth that eDRAM delivers. Of course this would mean also pretty radically different architechture as a whole, but that is the case usually on eDRAM based chips.