FB-DIMM style architecture for GPUs?

[_xxx_]

Well considering the work with nV on the PS3 that wouldn't be too far-fetched. But I think (without knowing anything ) that it's still a bit too expensive for the desktop.

 

[trinibwoy]

But RSX doesn't interface with XDR in PS3. Not sure what, if anything at all, was built into RSX with XDR in mind.

 

[INKster]

But RSX doesn't interface with XDR in PS3. Not sure what, if anything at all, was built into RSX with XDR in mind.

I think it does interface with XDR memory.
Didn't they talk about how it could access XDR with a Turbocache-like mecanism through EIB ?


edit
"(...)The RSX can render pixels to any part of memory, giving it access to the
full 512MB of memory of the PS3. We'd expect the technology used here to be
similar to NVIDIA's TurboCache that we've seen on the desktop."

http://anandtech.com/tradeshows/showdoc.aspx?i=2417&p=4

 

[trinibwoy]

I think it does interface with XDR memory.
Didn't they talk about how it could access XDR with a Turbocache-like mecanism through EIB ?

Well that sounds more to me like it interfaces with the EIB - that would be a bit different than working directly with a XDR memory controller. But you may be right - they may have gotten some insight into XDR but I'd be very surprised if they went that route. Rambus isnt exactly the most stable company out there and you don't have anywhere near the economies of scale that you would have with GDDR4.

 

[_xxx_]

But RSX doesn't interface with XDR in PS3. Not sure what, if anything at all, was built into RSX with XDR in mind.

FlexIO?

 

[trinibwoy]

Ah, yeah FlexIO - not EIB. Still too detached though. This is my understanding:

Rambus memory controller (MC) -> XDR : 3.2 Gb/s per pin
FlexIO -> memory controller : 36.5 GB/s read / 26 GB/s write

Now I would expect a GPU using XDR natively to forego FlexIO and just go with the MC built in like in today's designs. Nvidia might have experience dumping stuff onto the FlexIO bus in PS3, but would that automatically translate into expertise with the MC itself (designed by IBM in PS3)?.

Edit: took out some obvious bunk

 

[PeterAce]

May shed a little light on FlexIO and RSX :

http://www.beyond3d.com/forum/showpost.php?p=770917&postcount=34

 

[3dcgi]

Here's an article from this month's IEEE Spectrum magazine about the buses in the PS3.
http://spectrum.ieee.org/aug06/4256