Next generation Opteron 1207 pins!

[Keith R. Williams]

Not entirely.

Counter example? (though perhaps "socketed" is a better term)

 

[Robert Redelmeier]

Purchased, socketed, manufactured and tested, closer to a
dollar apiece.

Maybe CPUs, but 74xx logic and DRAM was closer to the dime.

X86 processors are still PGA. The marketing model still
demands it. Certainly BGA would be cheaper.

I was referring to how the dice are mounted on the PGA
carrier. They're not laced in, but AFAIK more like BGA.

What killed 'em was when it dropped to a half-dozen per
machine. The economy of scale went all to hell. ;-)

A victim of it's own success

~1K pins still amazes me. 1K balls, less so.

Hey, lift the cover on a ZIF socket -- familiarity breeds
contempt AFAIK, PGA packages are made exactly the same:
pot the pins in PCB, print a few layers (SMT otional)
and microBGA the die on.

-- Robert

 

[keith]

Maybe CPUs, but 74xx logic and DRAM was closer to the dime.

You remember differently that I (a dime wouldn't have made me look again,
though TTL stuff was only a dime a package, or less). I was always amazed
at the costs, but then there may have been a lot of overhead thrown in
there too (like me .

I was referring to how the dice are mounted on the PGA carrier. They're
not laced in, but AFAIK more like BGA.

Oh, that. Yes, IBM's C4 process (Controlled Collapsible Chip Connection)
from the '60s. ;-)
http://www-306.ibm.com/chips/technology/makechip/interconnect/4.html
It is rather like BGA, though "Chip-Scale" comes closer. ;-)

A victim of it's own success

Moore done 'em in. It's a conspiracy, I tell ya'.

Hey, lift the cover on a ZIF socket -- familiarity breeds contempt
AFAIK, PGA packages are made exactly the same: pot the pins in PCB,
print a few layers (SMT otional) and microBGA the die on.

Ziff *sockets* are a bit different. They remind me more of "a thousand"
tiny bobby pins.

 

[Mike Tomlinson]

Counter example? (though perhaps "socketed" is a better term)

Intel's new LGA Prescotts? (the pins are on the "socket")

 

[keith]

Intel's new LGA Prescotts? (the pins are on the "socket")

Still a *socket* (and a right scarry one). Try again...

 

[Robert Redelmeier]

Ziff *sockets* are a bit different. They remind me more of
"a thousand" tiny bobby pins.

They used to be that way. Now, ZIF sockets have pins
with a half-moon "C" head to connect with the CPU pins.

You cam probably comment better on PCB routing issues.
That's a _lot_ of traces even after half the pins are
tied to only ground or Vcc. Still, better than the
equivalent Northbridge 'cuz no ~100 from the CPU!

-- Robert

 

[JW]

Counter example? (though perhaps "socketed" is a better term)

Off the top of my head, Geode, AMD SC400, and Via's C3 come in BGA
packages.

 

[keith]

Off the top of my head, Geode, AMD SC400, and Via's C3 come in BGA
packages.

AIUI, Geode and SC400 are embedded processors, so BGA makes sense. C3 is
an interesting case, but I suspect it's there for the embedded market as
well.

 

[keith]

They used to be that way. Now, ZIF sockets have pins
with a half-moon "C" head to connect with the CPU pins.

That's what I mean by a "bobby pin", though perhaps with less of a tail.
The CPU pin goes into the center and is then cammed over into place with
spring tension of the 'C' tails making contact.

You cam probably comment better on PCB routing issues. That's a _lot_ of
traces even after half the pins are tied to only ground or Vcc. Still,
better than the equivalent Northbridge 'cuz no ~100 from the CPU!

I haven't looked at the pinout of one of these monsters, but I suspect
they've thought of that. The densest chip I've routed personally (I don't
do that stuff too often any more) was a Xininx FG680. The pinout was
designed to make routing rather simple. The inner balls were dedicated to
power/ground/references with the I/O mostly around the edge in the last
three/four rows so it could be routed out in two layers with two traces
per channel. I had five signal layers (though only three 50 ohm layers),
so routing wasn't too much of a problem. I suspect the Tiawaneese board
designers are more clever. ;-)

 

[Lady Chatterly]

Not entirely.

Not everything is as it seems Dick Tracy.