64-bit MBs that allow more than 4GB of non-registered RAM?

[Guest]

Are their any motherboards that accept more than 4GB of non-registered
RAM?

Tom Payne

[Tony Hill]

On Tue, 30 Dec 2003 00:57:31 +0000 (UTC), thp@cs.ucr.edu wrote:Are their any motherboards that accept more than 4GB of non-registeredRAM?

In a word, no. You can reach 4GB now, but not exceed it yet. Intel's
i865 and i875 chipsets are capable of handling 4 unregistered DIMMs of
1GB a piece. I believe that VIA and SiS have similar chipsets that
can also support up to 4GB of memory, but no more than that at this
point in time.

The main problem is simply that there are no 2GB unregistered DIMMs at
this point in time. Unregistered DIMMs can only support a maximum of
16 chips (2 banks of 8), and the largest memory chips being produced
at this time are 512Mbit chips. 16 x 512Mbit = 1GB. Combine that
with the maximum of 4 DIMM slots on a motherboard and that limits you
to 4GB. Putting more than 4 DIMMs on a board pretty much requires
registered memory.

Note that many motherboards that claim to support 4GB of memory are
not actually capable of doing so in a stable fashion. It seems that
testing a motherboard with the memory maxed out isn't deemed to be
important by most manufacturers.

-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca

[Guest]

Tony Hill <hilla_nospam_20@yahoo.ca> wrote:
+ On Tue, 30 Dec 2003 00:57:31 +0000 (UTC), thp@cs.ucr.edu wrote:
+>Are their any motherboards that accept more than 4GB of non-registered
+>RAM?
+
+ In a word, no. You can reach 4GB now, but not exceed it yet. Intel's
+ i865 and i875 chipsets are capable of handling 4 unregistered DIMMs of
+ 1GB a piece. I believe that VIA and SiS have similar chipsets that
+ can also support up to 4GB of memory, but no more than that at this
+ point in time.
+
+ The main problem is simply that there are no 2GB unregistered DIMMs at
+ this point in time. Unregistered DIMMs can only support a maximum of
+ 16 chips (2 banks of 8), and the largest memory chips being produced
+ at this time are 512Mbit chips. 16 x 512Mbit = 1GB. Combine that
+ with the maximum of 4 DIMM slots on a motherboard and that limits you
+ to 4GB. Putting more than 4 DIMMs on a board pretty much requires
+ registered memory.
+
+ Note that many motherboards that claim to support 4GB of memory are
+ not actually capable of doing so in a stable fashion. It seems that
+ testing a motherboard with the memory maxed out isn't deemed to be
+ important by most manufacturers.

Thanks, Tony. So, what are the prospects for the pricing of
registered RAM to drop? (Right now it seems to cost twice as much as
unregistered RAM.)

Tom Payne

[Tony Hill]

On Tue, 30 Dec 2003 11:51:39 +0000 (UTC), thp@cs.ucr.edu wrote:+ Note that many motherboards that claim to support 4GB of memory are+ not actually capable of doing so in a stable fashion. It seems that+ testing a motherboard with the memory maxed out isn't deemed to be+ important by most manufacturers.Thanks, Tony. So, what are the prospects for the pricing ofregistered RAM to drop? (Right now it seems to cost twice as much asunregistered RAM.)

Prospects are probably not so good. Registered memory is a bit of a
niche market, and since memory prices are really a supply/demand type
of thing, the niche market prices always tend to remain a bit high.

On the upside, unregistered 2GB DIMMs should arrive within six months
or so once the memory manufacturers start producing 1Gbit memory
chips. I was just checking a couple of sites it seems that they are
closer than I had previously thought. Micron claims that they're
already shipping 1Gbit memory chips and up to 2GB unregistered DIMMs
now, though I can't actually find any (Crucial, Micron's retail front
end, doesn't sell any yet). Samsung lists 1Gbit chips as being
engineering samples in Q3 and Q4 of '03, so production is probably not
too far off.

-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca