AMD 64 motherboards that support > 4GB of RAM

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Randy Howard

Are there any decent motherboards available for DIY construction that
support > 4GB of RAM with an AMD 64 CPU?

Similarly, how about dual or quad CPU boards with hypertransport?

Thanks...
 
Are there any decent motherboards available for DIY construction that
support > 4GB of RAM with an AMD 64 CPU?

Similarly, how about dual or quad CPU boards with hypertransport?

Thanks...

Any Opteron motherboard will support > 4G. The key is registered DIMMs
which Opterons use and Athlon 64s don't. The registering makes it possible
to put more RAMs on the DIMM. The biggest registered DIMMs available are
2G, the biggest unbuffered DIMM is only 1G so Athlon 64s max out at 4G
while Opterons can have 8G per processor.
 
Are there any decent motherboards available for DIY construction that
support > 4GB of RAM with an AMD 64 CPU?
Several AMD Athlon 64 processor-based motherboards currently support
some of the following memory features:

* PC1600, PC2100, PC2700 & PC3200 unbuffered memory modules. * 184-pin
2.5-Volt DDR DIMMs.
* 64-bit DDR memory bus.
* Supports 64-Mbyte, 128-Mbyte, 256-Mbyte, 512-Mbyte, 1-Gbyte, 2-Gbyte
and 4-Gbyte memory technology. * Supports production DIMMs from
industry standard DRAM memory manufacturers.

AMD list only 1 tested 2GB dimm and it's PC2100. Hard to dind a straight
answer but the above suggest that the memory controller will support DIMMS
up to 4GB in size. If that's the case, then current 4 dimm boards would
support 16GB if you can find 4GB dimm to go in them. I suggest you contact
AMD tech support for a clear answer or might be in the AMD specs. I didn't
look.
Similarly, how about dual or quad CPU boards with hypertransport?
Check Tyan website for up to 32GB.
 
Tyan and Iwill make several 2-4 CPU Opteron motherboards that should be
suitable.
There are other makes, but it looks like these companies have the "best"
offerings, including PCI-Express models. Apparently Tyan OEMs HP Workstation
MBs using NForce Pro.
As far as single CPU MBs, there may be single Opteron MBs that support >
4GB, but I'm not sure that they're cost effective. I don't recall seeing an
Opteron board that supports > 4GB.
 
Tyan and Iwill make several 2-4 CPU Opteron motherboards that should be
suitable.

I'll give them a look, thanks.
There are other makes, but it looks like these companies have the "best"
offerings, including PCI-Express models. Apparently Tyan OEMs HP Workstation
MBs using NForce Pro.

If HP will buy them, that's a good sign. They seem to still care
about quality, and haven't sold out to Intel only, as Dell announced
just the other day.
As far as single CPU MBs, there may be single Opteron MBs that support >
4GB, but I'm not sure that they're cost effective. I don't recall seeing an
Opteron board that supports > 4GB.

Strange, just about every "name brand" opteron system supports oodles
of memory, but they are mostly servers. The cream of the crop is the
Proliant DL585, a majorly fast system. Of course, it's mucho
expensive as well. I had a chance to work on one with 4 CPUs and
64GB of RAM for a couple of weeks a while back, and it was off the
charts fast, completely shredded any Xeon based server (with or
without EM64t) in existence.
 
AMD list only 1 tested 2GB dimm and it's PC2100. Hard to dind a straight
answer but the above suggest that the memory controller will support DIMMS
up to 4GB in size. If that's the case, then current 4 dimm boards would
support 16GB if you can find 4GB dimm to go in them. I suggest you contact
AMD tech support for a clear answer or might be in the AMD specs. I didn't
look.

I don't want to waste money on high density modules when more sockets
on the mobo would do just as well, particularly for SMP boards.
Check Tyan website for up to 32GB.

Thanks.
 
Sorry, that should say that "I don't recall seeing an _Athlon 64_ board that
supports > 4GB.
Opterons support 4 DIMMs/CPU or 8GB/CPU
 
Are there any decent motherboards available for DIY construction that
support > 4GB of RAM with an AMD 64 CPU?

Similarly, how about dual or quad CPU boards with hypertransport?

Thanks...

I just got this one this week. It will handle up to 4gb of ram in dual
channel mode at 400 mhz (PC3200) but only if all the sticks are single
sided. It's great so far. Single CPU only, though.

http://www.msicomputer.com/product/p_spec.asp?model=K8N_Neo4_Platinum&class=mb
 
HI, you should look at Win 2003 Server Standard Edition, 64 bit, you can
support up to 4 way Opteron with 32G memory registered ECC. With Win2003
Enterprise Server 64bit you can support up to 1TB!
 
HI, you should look at Win 2003 Server Standard Edition, 64 bit, you can
support up to 4 way Opteron with 32G memory registered ECC. With Win2003
Enterprise Server 64bit you can support up to 1TB!


There may be no AMD64 boards that support more than 4GB (3GB, really).
This is a marketing decision as the AMD64 chip can address 40 bits of
physical RAM. You can get a dual Operton system and stuff 8 or more
GB into it. You don't need to buy more than one CPU unless you need
it.

The rules for the new Intel 64 bit chip may be different.
 
There may be no AMD64 boards that support more than 4GB (3GB, really).

There are several Opteron boards that support 8GB per processor (four DIMM
slots per processor, 2GB each).
This is a marketing decision as the AMD64 chip can address 40 bits of
physical RAM. You can get a dual Operton system and stuff 8 or more
GB into it. You don't need to buy more than one CPU unless you need
it.

Several dual Opteron boards support 16GB (2 processors * 4 DIMMs * 2GB),
but memory only works on the installed processors. ;-)
The rules for the new Intel 64 bit chip may be different.

I'm sure Intel will be "different". ;-)
 
keith said:
Several dual Opteron boards support 16GB (2 processors * 4 DIMMs * 2GB),
but memory only works on the installed processors. ;-)

But even then, hypertransport lets cpu 0 get to cpu 1's RAM and vis versa,
it's just a bit slower than if the data was local.
 
There are several Opteron boards that support 8GB per processor (four DIMM
slots per processor, 2GB each).


Several dual Opteron boards support 16GB (2 processors * 4 DIMMs * 2GB),
but memory only works on the installed processors. ;-)


I'm sure Intel will be "different". ;-)


Are you sure about the need for a second CPU necessary to memory above
4GB ? By extrapolation that means that you need one CPU for every N
GB of memory, which doesn't scale.

Opteron is a MUMA architecture (non-uniform memory architecture) and
the memory is accessed thu a "fabric" (think switch or matrix) for all
CPU and I/O. Each CPU has local RAM but the RAM that's local
to other CPUs is accessable with an additional microcycle.
 
Are you sure about the need for a second CPU necessary to memory above
4GB ? By extrapolation that means that you need one CPU for every N
GB of memory, which doesn't scale.

Perhaps you need to read what I wrote again. I stated that 8GB was easily
(if not a tad pricey ;) possible on a single CPU system. The boards *I*
know about allow 8GB/preocessor (4DIMMs - 2GB each). Certainly this isn't
a limitation of the processor.
Opteron is a MUMA architecture (non-uniform memory architecture) and the
memory is accessed thu a "fabric" (think switch or matrix) for all CPU
and I/O. Each CPU has local RAM but the RAM that's local to other CPUs
is accessable with an additional microcycle.

Of course, OTOH, it's "sufficiently UMA" for < 8 processors. ...but
this doesn't change the facts, as stated.
 
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