Please Help me choose momory for AMD64

  • Thread starter Thread starter Synapse Syndrome
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S

Synapse Syndrome

I need to get a new PC in a *hurry* and my workload doesn't give me the time
to research this properly. This PC is to be used for architectural CAD and
3D modelling with quite a bit of Photoshop and DTP work as well. No games
or overclocking.

I've decided on these components for price/performance and necessary
features:

AMD Athlon64 3400+
Asus K8N-E Deluxe or K8V Deluxe / K8V SE Deluxe
3Dlabs Wildcat VP880 Pro

I'm not sure whether to go for the nForce-250GB or K8T800 chipset but I am
tending towards the nForce unless anybody can tell me the advantages of the
other.

But what really has me stumped is what memory to get. I need this new
computer as my current one can't smoothly handle the complex CAD models with
a lot of Geometry in OpenGL windows. It slows down too much for me to work
effectively. So I guess I need some pretty fast memory.

Should I get ECC memory? Matched pair? What brand? How low should I go
with the latency with price/performance and the rest of my system in mind
and the fact that I am not interested in overclocking or games.

Thanks for your help.

ss.
 
Andrew said:
I do not have all the answers as I've never looked into either board.

ECC memory should only be used on motherboards that require it. Also,
on some boards that take both, ECC only shows a benifit when using 3
or more sticks fo memory (in 1 ot 2 sticks, ECC was slower even with
the same speed. This was due to the increase in access time with non
ecc with 3+sticks).

lower access time RAM can be better if you are doing a lot of memory
accesses.

As much memory as can be fitted can help. check your current computer
when working and check out the maximum anount of RAM used (total of
real and virtural) Try to get this amount at least.

A matched pair of RAM is only important if the motherboard supports
dual RAM or you get a very good pair (RAM runs that the speed of the
slowest piece of ram normally)

No idea on brand, as long at it is a brand name should help.

hope this helps.
Click to expand...


Thanks. I'me not sure if the motherboards I've chosen support dual RAM, or
how much of a benefit this is.

ss.
 
Thanks. I'me not sure if the motherboards I've chosen support dual RAM, or
how much of a benefit this is.

ss.
 
Courseyauto said:
Thanks. I'me not sure if the motherboards I've chosen support dual RAM, or
how much of a benefit this is.

ss.
--------------------------------------------------------------------------
-------------------The memory controller is built into the CPU on the Athlon
64's.
The 940 and 939 pin are dual channel with the 940 being only for use with ECC
and registered ram. The 939 will use standard DDR ram,
Click to expand...


The K8N-E Deluxe supports ECC, un-buffered. Is it worth the extra, as I
will probably
 
Synapse Syndrome said:
The K8N-E Deluxe supports ECC, un-buffered. Is it worth the extra, as I
will probably
Click to expand...

Whoops. .. have 3 RAM modules eventually, which apparently needs ECC?

ss.
 
"Synapse Syndrome" said:
Whoops. .. have 3 RAM modules eventually, which apparently needs ECC?

ss.
Click to expand...

From the K8N-E Deluxe downloadable manual:

"3 x 184-pin DDR DIMM sockets for up to 3GB unbuffered
ECC and non-ECC PC3200/PC2700/PC2100/PC1600"

Qty. DIMM1 DIMM2 DIMM3 Max Speed
1 Single Side - - DDR400
1 - Single Side - DDR400
1 - - Single Side DDR400
1 Double Side - - DDR400
1 - Double Side - DDR400
1 - - Double Side DDR400
2 Single Side Single Side - DDR400
2 Single Side Double Side - DDR400
2 Single Side - Single Side DDR400
2 Single Side - Double Side DDR400
2 Double Side Single Side - DDR400
2 Double Side Double Side - DDR400
2 Double Side - Single Side DDR400
2 - Single Side Single Side DDR333
2 - Single Side Double Side DDR200
2 - Double Side Single Side DDR200
2 - Double Side Double Side DDR200
2 Double Side - Double Side DDR400 <--- Most
3 Single Side Single Side Single Side DDR333 Useful
3 Single Side Single Side Double Side DDR200 Config
3 Single Side Double Side Single Side DDR200
3 Single Side Double Side Double Side DDR200
3 Double Side Single Side Single Side DDR333
3 Double Side Single Side Double Side DDR200
3 Double Side Double Side Single Side DDR200
3 Double Side Double Side Double Side DDR200

While the manual says it can take 3 x 1GB double sided
unbuffered modules, you would only be able to run them
at 1/2 normal clock rate. That is why 2 x 1GB double
sided unbuffered modules is the most that can be practically
(and expensively) used.

ECC is slightly slower than non-ECC and the board can use
either. With ECC, if the processor wants to write only a
portion of a 64 bit chunk to one of the DIMMs, it has to
do a read-modify-write, and while this won't happen too
frequently, it is a difference between the two types. With
non-ECC, there are eight strobe signals that qualify a
write operation and identify which bytes in a chunk need
updating, and that avoids the need for read-modify-write.

ECC has the advantage of correcting single bit memory read
errors, which is useful for operating servers that must have
long up-times. For a desktop, memory reliability is usually
good enough, that ECC is not needed. If you buy an unbuffered
memory with ECC on it, usually the BIOS will show an extra
control entry, where the ECC can be enabled or disabled, so
you can actually benchmark with both settings and see what
the penalty is. Since ECC has an extra memory chip, it is
going to be more expensive.

The K8V series has the same requirements as those stated
above.

http://www.crucial.com/store/listpa...mfr=ASUS&cat=RAM&model=K8N-E+Deluxe&submit=Go

HTH,
Paul
 
Synapse Syndrome said:
The K8N-E Deluxe supports ECC, un-buffered. Is it worth the extra, as I
will probably
Click to expand...

Whoops. .. have 3 RAM modules eventually, which apparently needs ECC?

ss.
--------------------------------------------------------------------------
--------------------------
The ECC ram is mainly for servers,where reliability is important but it is not
as fast as non ECC ram. If you have a 754 3000 Athlon 64 it does not need ECC
ram... It is not what the MB takes for ram it is what the CPU requires. Dont
use any more ram than you need,it looks like the Athlon 64's are picky about
how much and what kind of ram it will like.... DOUG
 
Paul said:
From the K8N-E Deluxe downloadable manual:

"3 x 184-pin DDR DIMM sockets for up to 3GB unbuffered
ECC and non-ECC PC3200/PC2700/PC2100/PC1600"

Qty. DIMM1 DIMM2 DIMM3 Max Speed
1 Single Side - - DDR400
1 - Single Side - DDR400
1 - - Single Side DDR400
1 Double Side - - DDR400
1 - Double Side - DDR400
1 - - Double Side DDR400
2 Single Side Single Side - DDR400
2 Single Side Double Side - DDR400
2 Single Side - Single Side DDR400
2 Single Side - Double Side DDR400
2 Double Side Single Side - DDR400
2 Double Side Double Side - DDR400
2 Double Side - Single Side DDR400
2 - Single Side Single Side DDR333
2 - Single Side Double Side DDR200
2 - Double Side Single Side DDR200
2 - Double Side Double Side DDR200
2 Double Side - Double Side DDR400 <--- Most
3 Single Side Single Side Single Side DDR333 Useful
3 Single Side Single Side Double Side DDR200 Config
3 Single Side Double Side Single Side DDR200
3 Single Side Double Side Double Side DDR200
3 Double Side Single Side Single Side DDR333
3 Double Side Single Side Double Side DDR200
3 Double Side Double Side Single Side DDR200
3 Double Side Double Side Double Side DDR200

While the manual says it can take 3 x 1GB double sided
unbuffered modules, you would only be able to run them
at 1/2 normal clock rate. That is why 2 x 1GB double
sided unbuffered modules is the most that can be practically
(and expensively) used.

ECC is slightly slower than non-ECC and the board can use
either. With ECC, if the processor wants to write only a
portion of a 64 bit chunk to one of the DIMMs, it has to
do a read-modify-write, and while this won't happen too
frequently, it is a difference between the two types. With
non-ECC, there are eight strobe signals that qualify a
write operation and identify which bytes in a chunk need
updating, and that avoids the need for read-modify-write.

ECC has the advantage of correcting single bit memory read
errors, which is useful for operating servers that must have
long up-times. For a desktop, memory reliability is usually
good enough, that ECC is not needed. If you buy an unbuffered
memory with ECC on it, usually the BIOS will show an extra
control entry, where the ECC can be enabled or disabled, so
you can actually benchmark with both settings and see what
the penalty is. Since ECC has an extra memory chip, it is
going to be more expensive.

The K8V series has the same requirements as those stated
above.

http://www.crucial.com/store/listpa...mfr=ASUS&cat=RAM&model=K8N-E+Deluxe&submit=Go
Click to expand...


Thanks for the info. I'll assume that Double Sided means ECC RAM.

Cheers

ss.
 
Courseyauto said:
Whoops. .. have 3 RAM modules eventually, which apparently needs ECC?

ss.
--------------------------------------------------------------------------
--------------------------
The ECC ram is mainly for servers,where reliability is important but it is not
as fast as non ECC ram. If you have a 754 3000 Athlon 64 it does not need ECC
ram... It is not what the MB takes for ram it is what the CPU requires. Dont
use any more ram than you need,it looks like the Athlon 64's are picky about
how much and what kind of ram it will like.... DOUG
Click to expand...


I think I'll just get 2x256MB of non-parity RAM for now. Maybe I'll replace
them further down the line with 2x512MB if I feel the need.

Cheers

ss.
 
Thanks for the info. I'll assume that Double Sided means ECC RAM.

Cheers

ss.
Click to expand...

Double sided means there are two groups of chips, organized to support
64 bit wide read/write operations. In fact, it doesn't even mean the
chips physically have to be on either side of the module. I think
I've had a module here, where the two groups of chips are on the
same side of the module.

Here is how a 512MB module is constructed -

32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8
| | | | | | | | \
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit \
wide wide wide wide wide wide wide wide +---- Bank 0
data data data data data data data data /
| | | | | | | | / x64 data bus
================================================= on connector
| | | | | | | | \
data data data data data data data data \
wide wide wide wide wide wide wide wide +---- Bank 1
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit /
| | | | | | | | /
32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8

Next is an unbuffered 512MB module with ECC - it has an extra
chip per side. ECC forms a "checksum" for the 64 bits written
into the other chips. If only writing to a subset of chips,
the "checksum" must be rewritten, to make the value valid for
the whole 64 bits when it is read back. That is why a read-
modify-write cycle is needed for sub 64 bit writes.

32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8
| | | | | | | | |
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit
wide wide wide wide wide wide wide wide wide
data data data data data data data data data
| | | | | | | | | x72 data bus
======================================================= on connector
| | | | | | | | |
data data data data data data data data data
wide wide wide wide wide wide wide wide wide
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit
| | | | | | | | |
32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8 32Mx8

Here is a way to make a tricky 256MB module. This one uses eight
chips, so a casual glance would lead one to think it is a
single sided module. But, in fact, it is dual bank (double
sided, dual rank, pick a name). Using a utility, like maybe
CPUZ or Sandra, would tell you it is double sided. Few
modules have detailed specifications, and most vendors don't
have a clue what they are selling, so detecting stuff like
this, when it is important, is tough.

+---- Bank 0 ----+ +---- Bank 1 ----+
/ \ / \
/ \ / \
16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16
| | | | | | | |
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit
wide wide wide wide wide wide wide wide
data data data data data data data data
| | | | | | | | x64 data bus
======================================================= on connector

A 256MB module, "double sided", even though the eight
chips are on the same physical side of the module.
Dual bank or dual rank is a more meaningful terminology.

HTH,
Paul
 
+---- Bank 0 ----+ +---- Bank 1 ----+
/ \ / \
/ \ / \
16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16
| | | | | | | |
8bit 8bit 8bit 8bit 8bit 8bit 8bit 8bit
wide wide wide wide wide wide wide wide
data data data data data data data data
| | | | | | | | x64 data bus
======================================================= on connector

A 256MB module, "double sided", even though the eight
chips are on the same physical side of the module.
Dual bank or dual rank is a more meaningful terminology.
Click to expand...

Oops, messed up the diagram a bit. Chip connections should be
16 bits wide...

+---- Bank 0 ----+ +---- Bank 1 ----+
/ \ / \
/ \ / \
16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16 16Mx16
| | | | | | | |
16bit 16bit 16bit 16bit 16bit 16bit 16bit 16bit
wide wide wide wide wide wide wide wide
data data data data data data data data
| | | | | | | | x64 data bus
======================================================= on connector

Paul
 
I do not have all the answers as I've never looked into either board.

ECC memory should only be used on motherboards that require it. Also,
on some boards that take both, ECC only shows a benifit when using 3
or more sticks fo memory (in 1 ot 2 sticks, ECC was slower even with
the same speed. This was due to the increase in access time with non
ecc with 3+sticks).

lower access time RAM can be better if you are doing a lot of memory
accesses.

As much memory as can be fitted can help. check your current computer
when working and check out the maximum anount of RAM used (total of
real and virtural) Try to get this amount at least.

A matched pair of RAM is only important if the motherboard supports
dual RAM or you get a very good pair (RAM runs that the speed of the
slowest piece of ram normally)

No idea on brand, as long at it is a brand name should help.

hope this helps.
 
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