ACEFOMIQUZ wrote:If RSX is really for handling graphics,why SCE need CellBE as the CPU for PS3 but not PowerPC(970 for example) just like Macintosh or PC?
Huh? The answer is simple.
Ken Kutaragi
Ken, as you no doubt remember, originally started out as a DSP engineer at Sony. He doesn't really like CPU+GPU architectures. He likes CPU+DSP architectures.
from
http://www.blachford.info/computer/Cell/Cell1_v2.htmlThe Cell concept was originally thought up by Sony Computer Entertainment inc. of Japan, for the PlayStation 3. The genesis of the idea was in 1999 when Sony’s Ken Kutaragi “Father of the PlayStation” was thinking about a computer which acted like Cells in a biological system. A patent was applied for listing Masakazu Suzuoki and Takeshi Yamazaki as the inventors in 2002.
It is comprised of hardware and software Cells, software Cells consist of data and programs (known as jobs or apulets), these are sent out to the hardware Cells where they are computed, the results are then returned.
This architecture is not fixed, if you have a computer, PS3 and HDTV which have Cell processors they can co-operate on problems. They've been talking about this sort of thing for years of course but the Cell is actually designed to do it.
The original design of the PS3 did not have a PC-type GPU. They were going to use a custom, Sony designed chip for graphics output only, and do all of the 3D graphics generation on the Cell.
Ken had even proposed a Twin-Cell system at one point.
This is very similar to the PS2 design, BTW. Subsitute Cell for EE and "Unnamed Sony Chip" for GS, and you see where Ken was going.
Instead, according to "The Race For A New Game Machine", by Shippy & Phipps, Sony's design teams were unable to complete their graphics chip in time. This put the launch of the PS3 in jeopardy. A mad scramble ensued, and nVidia was able to take their 7800 chipset and roll it out to meet the Sony launch date and specifications.
Again - to be clear -
the RSX wasn't originally part of the PS3's design.
As for the "RSX can't be based on the 7800, etc.", here's a quote from David Kirk, Chief Scientist at nVidia:
The two products share the same heritage, the same technology. But RSX is faster
from
http://www.bit-tech.net/bits/2005/07/11 ... nterview/2and again from nVidia's Director of Public Relations, Derek Perez:
There's no doubting that NVIDIA's new 7800GTX is the ultimate in PC graphics technology. The card's G70 GPU, which is more than twice as powerful as two of NVIDIA's previous top-of-the-line 6800 boards, shares a lot of similar workings with the PS3's RSX chip - only it isn't as fast. Oh, and it retails for $599.
from
http://news.teamxbox.com/xbox/9132/Play ... orce-7800/ based on an article from September PSM, 2005.
Cheers,
Paul
P.S. For further reading, I'd suggest taking a quick glance here:
http://arstechnica.com/hardware/reviews/2000/02/ee.arsThis is the PS2 graphics pipeline. It represents a kind of shift away from PC architecture. I personally think Ken wanted this for the PS3 as well.
Also - you'll want to take a look at these:
http://www.edepot.com/playstation3.html#PS3_RSX_GPUand
http://www.edepot.com/playstation3.html ... PS3_Modelsfor more about the RSX and its history.
Also - I found the comments here a good read:
http://www.neogaf.com/forum/showthread.php?t=51518