IBM Broadway CPU; additional execution units over Gekko ?

[AirRa...@gmail.com]

http://www.neogaf.com/forum/showthread.php?t=118598

"Video of Broadway manufacturing reveals hint of Broadway die
size/power?

Someone on IGN boards found a video of Broadway being manufactured by
IBM."

http://boards.ign.com/nintendo_wii_lobby/b8270/126635337/p1/?8
Link to the thread

.
.
.
http://www-03.ibm.com/press/us/en/attachment/20213.wss?fileId=ATTACH_FILE1
Link to the video on IBM servers

On 0:10 we can see a wafer. It looks like it has 8 blocks with 7 CPUs
each, so that would be 56 CPUs in one line. The CPUs look square. If we
assume this is an 300mm wafer (anything else seems unlikely), then
Broadways die is about 5mm x 5mm = 25 mm^2. (300mm/56 = 5.36mm)

The Gekko die is 43 mm^2 but manufactured with a 180nm process. If you
would manufacture that design at 90nm like the Broadway it should be
about 11mm^2. So if the Broadway is really 25mm^2 it should offer quite
a bit of additional power over Gekko, not just a higher clockspeed.
512kb L2 cache instead of 256kb cache in the Gecko is pretty much a
given imho. IIRC the L2 cache uses under 50% of the Gekko die, so even
with 512kb cache we would still be around 15mm^2. So there is still
room for stuff that adds more performance like additional execution
units or splitting the Gekko pipeline into more steps to reach a even
higher clockspeed than would you would be able to get from the shrink
alone.

After looking at this evidence it seems pretty likely that Broadway is
quite a bit more than just a overclocked Gekko."
___________________________________________________________________________

Well that makes sense to me. Gekko, from what I understand, is a
modified IBM G3 CPU, basicly 1997-level technology, tweaked in
1999-2000 for release in a game console in 2001 at 485 MHz.

I would *hope* that Broadway is signifcantly more powerful than just a
~729 MHz Gekko.