A7N8X v2.0 Deluxe & memory

  • Thread starter Thread starter JSS
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J

JSS

I'm planning on upgrading my mem until I'm in a position to by a new
system. I currently have 2 OCZ400512R3 memory and was wondering if it
would be better to buy another OCZ400512R3 or some other mem.

I know it probably sounds stupid, I should use the same type of memory
but I just want to make sure.

Thanks
Jeff
 
JSS said:
I'm planning on upgrading my mem until I'm in a position to by a new
system. I currently have 2 OCZ400512R3 memory and was wondering if it
would be better to buy another OCZ400512R3 or some other mem.

I know it probably sounds stupid, I should use the same type of memory
but I just want to make sure.

Thanks
Jeff
Click to expand...

The first question is, what is your objective ? Does 1GB fail
to meet most of your needs ? Is most of memory filled ?

The reason I ask this, is your future system is likely to be
a dual channel motherboard. RAM will likely be installed in
pairs in the new system. If you buy one stick of 512MB now,
it will be an orphan in the new system. (Three sticks forces
a S939 board with a rev.e or later processor, to run in
single channel mode. Older S939 processors won't run with
three sticks at all.)

If you buy a S754 based system, three sticks would suck,
because the memory clock would have to be set so low to
get it to work. It might have to drop to DDR266 or DDR333.
One or two sticks is a better target number.

If you buy a S939 based system, it takes two or four sticks,
and the best config is to buy two sticks big enough for the
job. Some people buy 2x1GB, or 2x512MB is OK.
4x512MB can be more of a problem, and will need Command
Rate 2T timing. You won't be running a high RAM clock with
4x512MB in any case. A 2 stick configuration overclocks
much nicer.

If I was upgrading your A7N8X, I would put 2x512MB on
one channel, and a 1GB stick on the other channel.
That balances the quantity of memory on each channel,
and is a true dual channel configuration. If you
use 3x512MB, the bottom 1GB of memory runs at ~1400MB/sec
and the top 512MB of memory runs at ~900MB/sec. In other
words, with unbalanced memory, the balanced part runs
dual channel, and the unbalanced remainder runs in
single channel mode. (I know, because I modified a
copy of memtest86 to measure memory bandwidth through
the memory space, with a 3x512MB configuration.)

http://groups.google.ca/group/alt.c..._frm/thread/27e23db56f02cbf2/2dc03726c327f48d

If you look at the options below, no cheap option
fits well with the purchase of a new motherboard. Unless
there is a pressing need, hold onto your cash until you
are ready for the new system. Since AMD will eventually
be switching to DDR2, if you wait long enough, none of the
old memory will be usable in the new system anyway.

Options (row 1 and row 4 are the good ones):

A7N8X Operating mode (Future S939) Operating mode

2x512MB Dual Channel 2x512MB Dual channel (1T cmd rate)
3x512MB Mixed mode 3x512MB Single channel mode (Rev.E)
2x512MB+1GB Dual Channel 2x512MB+1GB Single channel mode (Rev.E)
2x1GB Dual Channel 2x1GB Dual channel (1T cmd rate)
2x512MB+2x1GB Dual channel (2T cmd rate)
4x512MB Dual channel (2T cmd rate)
4x1GB Dual channel (2T cmd rate)
(Only 3-3.5GB usable)

Another thing to note - there have been problems with
various S939 boards and four stick configurations that
should have worked. These could be BIOS related issues,
but check the private forums, to see if the situation
is improving, before purchasing a four stick config.

If buying 1GB DIMMs for either kind of system, get the
modules with 64Mx8 chips on them. The cheapest modules use
128Mx4 chips, and I read a warning recently that said only
half the memory is detected if you use those on an Nforce2.
I would not expect the S939 system to be happy with those
sticks either, as the loading might force the use of a lower
clock rate. The memory in the right hand column of this advert,
is an example of the bad RAM.

http://www.portatech.com/catalog/memory.asp?ID=285

HTH,
Paul
 
The first question is, what is your objective ? Does 1GB fail
to meet most of your needs ? Is most of memory filled ?

The reason I ask this, is your future system is likely to be
a dual channel motherboard. RAM will likely be installed in
pairs in the new system. If you buy one stick of 512MB now,
it will be an orphan in the new system. (Three sticks forces
a S939 board with a rev.e or later processor, to run in
single channel mode. Older S939 processors won't run with
three sticks at all.)

If you buy a S754 based system, three sticks would suck,
because the memory clock would have to be set so low to
get it to work. It might have to drop to DDR266 or DDR333.
One or two sticks is a better target number.

If you buy a S939 based system, it takes two or four sticks,
and the best config is to buy two sticks big enough for the
job. Some people buy 2x1GB, or 2x512MB is OK.
4x512MB can be more of a problem, and will need Command
Rate 2T timing. You won't be running a high RAM clock with
4x512MB in any case. A 2 stick configuration overclocks
much nicer.

If I was upgrading your A7N8X, I would put 2x512MB on
one channel, and a 1GB stick on the other channel.
That balances the quantity of memory on each channel,
and is a true dual channel configuration. If you
use 3x512MB, the bottom 1GB of memory runs at ~1400MB/sec
and the top 512MB of memory runs at ~900MB/sec. In other
words, with unbalanced memory, the balanced part runs
dual channel, and the unbalanced remainder runs in
single channel mode. (I know, because I modified a
copy of memtest86 to measure memory bandwidth through
the memory space, with a 3x512MB configuration.)

http://groups.google.ca/group/alt.c..._frm/thread/27e23db56f02cbf2/2dc03726c327f48d

If you look at the options below, no cheap option
fits well with the purchase of a new motherboard. Unless
there is a pressing need, hold onto your cash until you
are ready for the new system. Since AMD will eventually
be switching to DDR2, if you wait long enough, none of the
old memory will be usable in the new system anyway.

Options (row 1 and row 4 are the good ones):

A7N8X Operating mode (Future S939) Operating mode

2x512MB Dual Channel 2x512MB Dual channel (1T cmd rate)
3x512MB Mixed mode 3x512MB Single channel mode (Rev.E)
2x512MB+1GB Dual Channel 2x512MB+1GB Single channel mode (Rev.E)
2x1GB Dual Channel 2x1GB Dual channel (1T cmd rate)
2x512MB+2x1GB Dual channel (2T cmd rate)
4x512MB Dual channel (2T cmd rate)
4x1GB Dual channel (2T cmd rate)
(Only 3-3.5GB usable)

Another thing to note - there have been problems with
various S939 boards and four stick configurations that
should have worked. These could be BIOS related issues,
but check the private forums, to see if the situation
is improving, before purchasing a four stick config.

If buying 1GB DIMMs for either kind of system, get the
modules with 64Mx8 chips on them. The cheapest modules use
128Mx4 chips, and I read a warning recently that said only
half the memory is detected if you use those on an Nforce2.
I would not expect the S939 system to be happy with those
sticks either, as the loading might force the use of a lower
clock rate. The memory in the right hand column of this advert,
is an example of the bad RAM.

http://www.portatech.com/catalog/memory.asp?ID=285

HTH,
Paul
Click to expand...

Thanks for a very thought out reply. The reason for upgrading the
memory is that I seem to be running out of memory for the apps I'm
running.

I now have more issues to think about before I can make a decision.

Thanks

Jeff
 
JSS said:
Thanks for a very thought out reply. The reason for upgrading the
memory is that I seem to be running out of memory for the apps I'm
running.

I now have more issues to think about before I can make a decision.

Thanks

Jeff
Click to expand...

I've run Linux on 3x512MB on A7N8X-E, so I'm not saying it
cannot be done. My purpose in posting all of that, is to show
that if you are buying memory for machine of different eras,
there can be a lot of small issues to deal with. (Like doing
all the research for the purchase of the new motherboard,
without actually buying it.)

Certainly buying one 512MB stick now is not going to "break
the bank", if you are willing to change strategies when the
replacement motherboard comes along. But reducing the
compatibility risks to zero, and getting to use all the RAM
without introducing some limits into the new platform, is
tougher to do.

Paul
 
I've run Linux on 3x512MB on A7N8X-E, so I'm not saying it
cannot be done. My purpose in posting all of that, is to show
that if you are buying memory for machine of different eras,
there can be a lot of small issues to deal with. (Like doing
all the research for the purchase of the new motherboard,
without actually buying it.)

Certainly buying one 512MB stick now is not going to "break
the bank", if you are willing to change strategies when the
replacement motherboard comes along. But reducing the
compatibility risks to zero, and getting to use all the RAM
without introducing some limits into the new platform, is
tougher to do.

Paul
Click to expand...
I agree that the technology is changing too fast that something
purchased a year or two ago is now obsolete and not useable in current
generation systems. Is seems that by the time you find something you
like and put away the money for it (I'm credit challenged)


I saw this awhile ago and think it would make a killer system,
http://www.iwill.net/product_2.asp?p_id=36&sp=Y but by the time I save
up enough money it will be outdated.

Jeff
 
Paul wrote:

If I was upgrading your A7N8X, I would put 2x512MB on
one channel, and a 1GB stick on the other channel.
That balances the quantity of memory on each channel,
and is a true dual channel configuration. If you
use 3x512MB, the bottom 1GB of memory runs at ~1400MB/sec
and the top 512MB of memory runs at ~900MB/sec. In other
words, with unbalanced memory, the balanced part runs
dual channel, and the unbalanced remainder runs in
single channel mode. (I know, because I modified a
copy of memtest86 to measure memory bandwidth through
the memory space, with a 3x512MB configuration.)

http://groups.google.ca/group/alt.c..._frm/thread/27e23db56f02cbf2/2dc03726c327f48d
Click to expand...

Thank you very much, Paul for breaking this in in a plain and understandable
manner. I've searched for info on this the whole time I've owned my mobo and
never got a good answer. Now I did.
 
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