Cell Processor vs Dual-Processor Apple Power Mac G5
- Thread starter aldo
- Start date
0,85 fps (2.7GHz G5/VMX)
30 fps (Cell BE)
http://www-128.ibm.com/developerworks/power/library/pa-cellperf/
30 fps (Cell BE)
http://www-128.ibm.com/developerworks/power/library/pa-cellperf/
DuckThor Evil
Legend
If it is the same landscape demo that was seen at E3, it used 2 Cell's, still beating G5 by a healty margin though.
ihamoitc2005
Veteran
1 Cell & 2 Cell
With 1 CELL it is 720P @ 30fps with 2 CELL it is 1080P @ 30fps but I do not know what is performance of PS3 CELL with 7 SPE. I think terrain demo CELL has 8 SPE.
Dr Evil said:
With 1 CELL it is 720P @ 30fps with 2 CELL it is 1080P @ 30fps but I do not know what is performance of PS3 CELL with 7 SPE. I think terrain demo CELL has 8 SPE.
ihamoitc2005
Veteran
Synergy34 said:
http://www.research.ibm.com/cell/whitepapers/cell_online_game.pdf#search='terrain%20demo%20CELL%20SPE'
ihamoitc2005 said:
Barry Minor of IBM answers some questions:
http://gametomorrow.com/blog/index.php/2005/07/26/beyond-polygons/
Also see this:
http://www.graphicshardware.org/presentations/damora-cell4graphicsandviz-gh05.pdf
CELL mentioned in presentation is 2.8Ghz with 8 SPE
ihamoitc2005 said:
One of the SPUs was being used for jpeg compression of the framebuffer, to send it over the network to a client. 7 of the SPUs were being used for the actual rendering. If you were just interested in rendering the scene to a "local" screen, connected directly to the system, PS3 Cell's performance would be the same (well, difference in clockspeed aside, depending on whether you're looking at 2.4Ghz Cell numbers, or 2.8 or 3.2).
edit - Actually, to correct myself, from the article:
So that SPU that's used for compression is also actually doing some rendering work. So even in the above scenario I described, there'd probably be a slight drop in performance.
Didn't realise initially that there were 3 pages to the article linked to!
Also, another interesting detail that was new to me at least:
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ihamoitc2005
Veteran
variable SPE use
Yes. This makes sense to me because SPE can take load as what is required. So maybe actual performance is same for PS3 CELL because since SPE can take load as what is required, 7 SPE @ 3.2Ghz of PS3 is same performance as 8 SPE at 2.8Ghz which is used for terrain demo.
I am curious how missing SPE has effect on jumps for EIB data transfer and EIB bandwidth efficiency.
Titanio said:
Yes. This makes sense to me because SPE can take load as what is required. So maybe actual performance is same for PS3 CELL because since SPE can take load as what is required, 7 SPE @ 3.2Ghz of PS3 is same performance as 8 SPE at 2.8Ghz which is used for terrain demo.
I am curious how missing SPE has effect on jumps for EIB data transfer and EIB bandwidth efficiency.
It seems that the Earth Terrain Demo is made for a CPU with huge vector processing and it runs in Vector Processing Units only instead os Scalar Units.
The G5 isn´t underpowered, clocked at 2.5Ghz it could do 25 GFLOPS (FPU) and others 40 GFLOPS (VMX), is a very good Floating Point performance for a General Purpose CPU that only has one core.
The G5 isn´t underpowered, clocked at 2.5Ghz it could do 25 GFLOPS (FPU) and others 40 GFLOPS (VMX), is a very good Floating Point performance for a General Purpose CPU that only has one core.
I find this demo very interesting, and can see large height maps being used for many types of games. Now the resolution of this one was 10 meters between points, and would be suitable for a flight game of some sort, giving an area of 80 km by 80 km.
The matrix size was roughly 8000x8000 using 16-bit values, and that translates into 128 MB of data. That's a monsterous size matrix, and CELL had no problems dealing with it!
That matrix might be a bit big for a lot of games interms of memory storage, and 4000x4000 using 16-bit values might be more suitable, taking up 32 MB of memory. If it's a character on the ground type of game, you would need the data points closer togeather, like on the order of 1 meter, so 4000x4000 would give an area of 4 Km by 4 Km. Might even use some pixel shading over points to help hide polygonal edges. A matrix of this size would leave a lot more memory for other game assets, compared to a 8000x8000 matrix.
It would be interesting also if a game engine could create curved geometry between points, to help hide any point to point angularity. It could do this, only a certain distance from the user to keep such processing overhead low.
With CELL's massive bandwidth and floating point power, I see games using height maps much more with this upcoming generation than the last generation. I would be hard pressed to even think how many PS2 games used a height map.
Another thing to consider is that depending on your games visiblity distance (weather effects limiting visiblity distance) and the perspective in the game world (low to the ground or high in the air makes a difference), you could even stream in different height maps depending on your location in the game world. I think World of Warcraft uses this technique to good effect, as moving from one region to another is seamless, as it streams in the next area as you are moving towards it.
The matrix size was roughly 8000x8000 using 16-bit values, and that translates into 128 MB of data. That's a monsterous size matrix, and CELL had no problems dealing with it!
That matrix might be a bit big for a lot of games interms of memory storage, and 4000x4000 using 16-bit values might be more suitable, taking up 32 MB of memory. If it's a character on the ground type of game, you would need the data points closer togeather, like on the order of 1 meter, so 4000x4000 would give an area of 4 Km by 4 Km. Might even use some pixel shading over points to help hide polygonal edges. A matrix of this size would leave a lot more memory for other game assets, compared to a 8000x8000 matrix.
It would be interesting also if a game engine could create curved geometry between points, to help hide any point to point angularity. It could do this, only a certain distance from the user to keep such processing overhead low.
With CELL's massive bandwidth and floating point power, I see games using height maps much more with this upcoming generation than the last generation. I would be hard pressed to even think how many PS2 games used a height map.
Another thing to consider is that depending on your games visiblity distance (weather effects limiting visiblity distance) and the perspective in the game world (low to the ground or high in the air makes a difference), you could even stream in different height maps depending on your location in the game world. I think World of Warcraft uses this technique to good effect, as moving from one region to another is seamless, as it streams in the next area as you are moving towards it.
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