Which exact model of RAM do I need? :-S

  • Thread starter Thread starter M.J.S.
  • Start date Start date
M

M.J.S.

I am buying a new system soon, but as for my old/current system... which I
will keep as a 2nd computer on the network (it's a Dual Core Opteron 180
running on an Asus A8N-SLI Deluxe withWinXP x64) I'd like to upgrade the
RAM, but that's a really complicated area for me as I've tried it before on
another system and ended up buying the wrong sticks.

I am currently using 2 sticks of (according to SIW.exe):

Manufacturer: Corsair
Part Number: CMX1024-3200C2
Capacity: 1024 MBytes
Memory Type: SDRAM DDR
Speed: PC3200 (200 MHz)
(but websites report this model actually does 400mhz, not 200)
Data Width: 64 bits
Voltage: SSTL 2.5V
Error Correction: None
Refresh: Reduced (.5x)...7.8 µs
EPP SPD Support: No

And my shopping options as a Canadian are pretty limited.
In-store, there's :
http://www.microbytes.com/computer/ordinateur/index.php?cPath=2030000
Online, it's :
http://www.ncix.com/products/index.php?minorcatid=105

What can I safely add to my MB from either of these two? There are 2 slots
left.
 
M.J.S. said:
I am buying a new system soon, but as for my old/current system... which I
will keep as a 2nd computer on the network (it's a Dual Core Opteron 180
running on an Asus A8N-SLI Deluxe withWinXP x64) I'd like to upgrade the
RAM, but that's a really complicated area for me as I've tried it before on
another system and ended up buying the wrong sticks.

I am currently using 2 sticks of (according to SIW.exe):

Manufacturer: Corsair
Part Number: CMX1024-3200C2
Capacity: 1024 MBytes
Memory Type: SDRAM DDR
Speed: PC3200 (200 MHz)
(but websites report this model actually does 400mhz, not 200)
Data Width: 64 bits
Voltage: SSTL 2.5V
Error Correction: None
Refresh: Reduced (.5x)...7.8 µs
EPP SPD Support: No

And my shopping options as a Canadian are pretty limited.
In-store, there's :
http://www.microbytes.com/computer/ordinateur/index.php?cPath=2030000
Online, it's :
http://www.ncix.com/products/index.php?minorcatid=105

What can I safely add to my MB from either of these two? There are 2 slots
left.
Click to expand...
Any of these are fine. Just make sure it's DDR PC3200.
http://www.ncix.com/products/index.php?minorcatid=105&subminorcatid=10
 
M.J.S. said:
I am buying a new system soon, but as for my old/current system... which I
will keep as a 2nd computer on the network (it's a Dual Core Opteron 180
running on an Asus A8N-SLI Deluxe withWinXP x64) I'd like to upgrade the
RAM, but that's a really complicated area for me as I've tried it before on
another system and ended up buying the wrong sticks.

I am currently using 2 sticks of (according to SIW.exe):

Manufacturer: Corsair
Part Number: CMX1024-3200C2
Capacity: 1024 MBytes
Memory Type: SDRAM DDR
Speed: PC3200 (200 MHz)
(but websites report this model actually does 400mhz, not 200)
Data Width: 64 bits
Voltage: SSTL 2.5V
Error Correction: None
Refresh: Reduced (.5x)...7.8 µs
EPP SPD Support: No

And my shopping options as a Canadian are pretty limited.
In-store, there's :
http://www.microbytes.com/computer/ordinateur/index.php?cPath=2030000
Online, it's :
http://www.ncix.com/products/index.php?minorcatid=105

What can I safely add to my MB from either of these two? There are 2 slots
left.
Click to expand...

OCZ4002048ELDCPE-K 2x1GB $138.99

http://www.ncix.com/products/index.php?sku=14504&promoid=1025

Reviews here:

http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16820227210

Looking at the reviews, I can see a couple reports of failures after
the RAM has been in use for a while. The product has a lifetime warranty,
but must be returned and tested to get a replacement.

With that family of processors, you can run DDR400 Command Rate 1T with
two sticks. Once four sticks are running in there, the BIOS may select
DDR333. You should be able to manually adjust, to either DDR400 Command
Rate 2T, or DDR333 Command Rate 1T. But four sticks cannot run at DDR400
Command Rate 1T. The timing can probably be left as is, at CAS2. Test
with memtest86+, prime95 or orthos, before considering the job done. I
don't know if the latter two have a problem with a 64 bit OS or not.

Four sticks will not match the memory bandwidth of two sticks. It'll
be a bit less, due to the changed settings.

If this is to become a secondary computer, and it already has 2x1GB,
why fill it with RAM ? Instead, fill the new primary machine with
RAM, because DDR2 is dirt cheap, and just leave the old machine
as is.

Paul
 
M.J.S. said:
So you can mix Corsair with - for example - Crucial or Kingston? It doesn't
have to be the same brand? Because I already have 2 sticks on the board.
Click to expand...
No only each pair must be identical.
 
If you are upgrading to a new sys why are you concened about upgrading ram
on the old sys?
You are unlikely to see any performance increase, excepting with specific
software
 
old man said:
If you are upgrading to a new sys why are you concened about upgrading ram
on the old sys?
You are unlikely to see any performance increase, excepting with specific
software
Click to expand...

Well, yes. That specific software is why I want to upgrade it.
 
Paul said:
OCZ4002048ELDCPE-K 2x1GB $138.99

http://www.ncix.com/products/index.php?sku=14504&promoid=1025
Click to expand...

Hi Paul,

Here's what someone else recommended, and I'd be curious to have your
thoughts on the logic :

your prices via that ncix site quite frankly are absurd. Since you intend to
keep this as a second computer, I would buy 1, 2 or 3 of these:

http://www.ncix.com/products/index.php?sku=15556&vpn=VS1GB400C3&manufacture=CORSAIR

....at $65 each. They have a slightly slower timing than what you currently
have in there, but whats in there now will just be bumped to that slower
timing when this is added. In terms of that speed "difference", you'll never
see it. In most things having MORE ram matters a lot more than having "fast"
ram. Value ram is generally the way to go unless you need really "fast" ram
to overclock with. How much you put in (1,2, or 3 sticks) is up to you, I
would probably buy 1 more stick and leave it at that. A dual core with 2 gig
is a lot more snappy than it is with just 1 in my experience.

-----

Do you agree with the above? And if not, why not?
If this is to become a secondary computer, and it already has 2x1GB,
why fill it with RAM ? Instead, fill the new primary machine with
RAM, because DDR2 is dirt cheap, and just leave the old machine
as is.
Click to expand...

Because the new machine isn't bought yet, and I might have to wait 'til Xmas
for it. Also, the "old" machine will be networked with the new and in use
quite a bit... not left in a locker somewhere. In fact, I don't think it
qualifies as a "old machine" per se. More like a 2nd active unit.
 
M.J.S. said:
I am buying a new system soon, but as for my old/current system...
which I will keep as a 2nd computer on the network (it's a Dual
Core Opteron 180 running on an Asus A8N-SLI Deluxe withWinXP x64)
I'd like to upgrade the RAM, but that's a really complicated area
for me as I've tried it before on another system and ended up
buying the wrong sticks.
Click to expand...

Nothing says whether the mother board is capable of accepting and
using ECC memory. If so, I suggest you restrict your search to ECC
memory, since the end result is much more reliable. Most people do
not realize that absolutely nothing else dynamically checks the
correctness of memory operation, and that memory errors can be due
to unpredictable things such as cosmic rays.

So your first job should be to find out whether the MB takes ECC
memory. If so, the additional cost for reliability will be only a
few dollars.
 
M.J.S. said:
Hi Paul,

Here's what someone else recommended, and I'd be curious to have your
thoughts on the logic :

your prices via that ncix site quite frankly are absurd. Since you intend to
keep this as a second computer, I would buy 1, 2 or 3 of these:

http://www.ncix.com/products/index.php?sku=15556&vpn=VS1GB400C3&manufacture=CORSAIR

...at $65 each. They have a slightly slower timing than what you currently
have in there, but whats in there now will just be bumped to that slower
timing when this is added. In terms of that speed "difference", you'll never
see it. In most things having MORE ram matters a lot more than having "fast"
ram. Value ram is generally the way to go unless you need really "fast" ram
to overclock with. How much you put in (1,2, or 3 sticks) is up to you, I
would probably buy 1 more stick and leave it at that. A dual core with 2 gig
is a lot more snappy than it is with just 1 in my experience.

-----

Do you agree with the above? And if not, why not?


Because the new machine isn't bought yet, and I might have to wait 'til Xmas
for it. Also, the "old" machine will be networked with the new and in use
quite a bit... not left in a locker somewhere. In fact, I don't think it
qualifies as a "old machine" per se. More like a 2nd active unit.
Click to expand...

My policy on RAM upgrades, is to match what people already have.

Why do I do this ?

Because I assume the buyer has already expressed their priorities, in
the form of the purchased object. If a guy buys unlabeled CAS3 from Ebay,
I know his priority was price. Since it is CAS3, I couldn't recommend CAS2
in that case anyway, because all the RAM together would only run at CAS3.

When a guy has bought more expensive RAM, that says the priority was
performance over price. Does it make sense to add some Ebay CAS3 memory
to that machine ? For one thing, I might get a rabid response "you're
trying to slow down my machine!" from the OP if I did that.

So I assume the RAM the person currently has, is an expression of their
priorities. If, on the other hand, the person said "what can I get for
$65", then that would be an invitation to write a long post about the
tradeoffs.

So I tried to match memory type, as best I could, with the best price
I could find.

If you don't care what CAS you run, then sure, stick the cheaper
product in there. Check the reviews, to see whether the memory has
any headroom at all (some cheap products are binned so close to
PC3200, they won't even run a few MHz more than the stock speed).
You also want to check to see whether people report any DOAs
for the sticks, and you'd also want to check the warranty, in case
the stuff has a habit of dying in the months after purchase.

So what kind of performance will you get ?

First off, there is a difference between memory bandwidth and applications
performance changes. I use a "1/3rd" rule for this, which I'll demonstrate
in a moment.

Changing from CAS2 to CAS3, is a 10% reduction in memory bandwidth (as well
as a change in latency). Changing from Command Rate 1T to 2T is a 20% reduction
in memory bandwidth. And if you couldn't get the memory error free at DDR400,
then changing to DDR333 is another factor of 20%.

I'm assuming in your case, you'll manage to run DDR400 Command Rate 2T, so you'll
lose the 20%. Using CAS3 memory is another 10%, so the total is 30%. Using
the 1/3rd rule, your applications will average a 30% / 3 = 10% reduction in
operating speed.

So the memory upgrade is not simply double what you had before. It is double,
but a bit slower. Do your applications really need 4GB of memory ? If you were
planning on installing Vista, then I'd call your plan "good insurance". If
you will continue to use some form of WinXP, then I'd seriously review what
all the memory will be used for, before upgrading.

The best config for the S939 platform, was two matched sticks of RAM. You
currently have the best configuration. To want more, is a compromise, and
it is up to you to decide whether you'll be using 4GB every day. You can
use Task Manager now, if you want, to watch how much memory is in use during
your peak usage periods.

What I have, is two reasonably current computers, and four sticks of RAM.
If, on a given day, a special project called for a lot of RAM, I simply pull
it out of one machine, and plug it into the other. That is my solution to that
kind of problem. So far, I haven't had to do that.

Also, this RAM, is $138 for TWO sticks of RAM. It is a 2x1GB kit.
It is also $118 after you use the mail in rebate, but I don't tend to count
on those. $118 for two sticks, is cheaper than 2 x $65.

http://www.ncix.com/products/index.php?sku=14504&promoid=1025

Paul
 
CBFalconer said:
So your first job should be to find out whether the MB takes ECC
memory. If so, the additional cost for reliability will be only a
few dollars.
Click to expand...

I've no idea what ECC is. The MB is an Asus A8n-SLI Deluxe. You tell ME if
it's ECC-compliant. ;-)
 
M.J.S. said:
Sounds like sound logic to me.

So the fact that the ram is not the same company or model is a non-issue in
your view?
Click to expand...

OK, I can think of a couple potential issues.

On some RAM, the RAM is rated CAS2 on one side and CAS2.5 on the other.
Some chipsets or devices seem to have a timing problem with certain brands
of RAM chips, requiring the manufacturer to list a different number for
AMD and Intel systems. That is the only reason I can think of, right off hand,
where you might not get the stated, single spec timing.

http://www.ocztechnology.com/products/memory/ocz_el_ddr_pc_3200_dual_channel_platinum

The second issue, is voltage spec for enthusiast RAM. If one RAM really
needs a high voltage to achieve its stated tight timing, while another
RAM product doesn't like that high voltage, then mixing them may require
backing off on the overall spec. (For example, you wouldn't mix Winbond BH5
with other, wimpier RAM.) The Corsairmicro is 2.75V test voltage,
while the OCZ can handle up to 2.8V, so they seem well matched in that
regard. I'm guessing the lower spec mentioned in the datasheet for the OCZ,
implies you can meet the timing spec with less voltage than the max.

http://www.corsairmicro.com/_datasheets/CMX1024-3200C2.pdf

I don't see a reason you shouldn't be able to use two matched pairs from
different companies. Granted, there have been problems in the past, with
the initial BIOSes on some of the motherboards, where they do crazy things.
But that doesn't change the technical side of things. For example, I would
expect less problems on my P4C800-E, in mixing brands, while some of the
original AMD Athlon64 BIOS would do things like "ignore" the second set
of added sticks. Some of the AMD BIOS had excessively strict "matching"
checks on the RAM sticks, where they were even checking the PCB revision
of the RAM stick. But if your BIOS is up to date, for the most part that
should be fixed. On some boards, the only remaining issue, might be
the BIOS refusing to accept a manual setting of DDR400 with four sticks.

If you want to check the "fossil record", try reading postings here about
RAM issues. There are close to 4000 threads here, so there should be a
few examples of mixed RAM configs. There is a search box, but depending
on the search terms used, you might miss some good threads, if they don't
have descriptive titles.

http://vip.asus.com/forum/topic.asp...8N-SLI Deluxe&page_size=100&page=1&count=3936

If I absolutely had to have 4GB of RAM, I wouldn't have a problem with the
above plan. As with anything, the more research you do, the more informed
you are.

HTH,
Paul
 
Also, a couple other comments. When you get the new RAM, try it with
your existing BIOS. Or, at least, examine all the BIOS release notes,
to see what side effects a BIOS upgrade could have. For example, the
1016 has a chipset driver dependency in the OS. If the chipset
drivers are already higher than the stated revisions below, then it
would be safe to upgrade the BIOS to 1016 or higher.

http://support.asus.com/download/download.aspx?SLanguage=en-us&model=A8N-SLI Deluxe

"Please do read the description before updating BIOS
To avoid crashing file system, please do update the chipset driver to below
version prior to this Bios.

For WinXP 32bit system, please download and update chipset drivers V6.65 or later
For WinXP 64bit system, please download and update chipset drivers V6.65 or later
For Win2k/2003 32bit system, please download and update chipset drivers V6.66 or later
For Win2003 64bit system, please download and update chipset drivers V6.66 or later"

As for the ECC comment, ECC is error checking and correcting. When a memory
DIMM has a (ninth) parity chip on it, it allows the detection of multi-bit
errors, and the correction of single bit errors. When a large quantity of RAM
is involved, it provides a means of the user having errors corrected in the
background (for the single bit ones), or an error showing on the screen, to
inform you of the potential for a calculation to be corrupted. Without ECC,
you might not notice that a bit error has occurred in the RAM.

ECC support is required in two places to work. The DIMM has to have the ninth
chip populated on both sides, giving a 72 bit wide data array, compared to the
normally 64 bit wide DIMMs. The chipset also must have the provision for the
extra data bus wires, and have an ECC logic block to do the ECC calculation.
The Athlon64 family has the ECC chipset support built in, so any Athlon64
should be a candidate (check the manual to verify the support is there, to
be absolutely sure).

The Athlon64 has two error correction modes. It has the normal SECDED, which
corrects a single bit in error, in a 64 bit data word. In other words 64 bits
data plus 8 bits parity, allows correcting any single bit in error in the
entire 72 bit quantity (even an error in the ECC section can be fixed). If
two bits are in error, that fact can be detected but not corrected. If more
than two bits are in error, then statistics come into play, as only some error
patterns will be detected, while the undetected ones are no worse than using
non-ECC RAM.

The second mode is called "chip kill". It relies on dual channel configurations
of RAM. It treats the data bus as being 144 bits wide. It fetches data from
both DIMMs, so there is 128 bits of data and 16 bits of parity. Chipkill mode
allows up to four bits in error, clustered together, to be corrected. On
server systems (probably not that useful in your case), where x4 nibble wide
memory chips on registered DIMMs are quite common, it allows a single x4 wide
memory chip to completely die, and the pair of DIMMs will continue to work as
if nothing happened. (If you've ever worked on a system with bad memory, with a
dead chip or data bus bit, with ECC enabled, you'll realize there is a cost.
The system continues to run, but it may crawl. I had a Unix machine that did
manage to continue running without a problem, until maintenance arrived to swap
out the RAM, but it did slow down noticeably. We kept it running, to see
if it would crash or not, and it stayed up and you could still work on it.)

Now, in your particular situation, it is a bit much to ask you to remove the
two, non-ecc RAM you currently own, and buy four sticks each equipped with
ECC and install them. All RAM has to have ECC, for you to be able to enable
it in the BIOS. If you were buying RAM from scratch, then suggesting ECC for
that much RAM would make sense. Again, it is a call on your part, as to whether
you feel the extra reliability of ECC protection, is worth the extra hassle or
not. I cannot make that call for you. If you are a banker doing accounts,
then you'd add it :-) If a gamer, then the occasional reboot, or crash out
to desktop, is not the end of the world. Some users just are not that
demanding of enhanced reliability, to go the extra mile. The machine I'm
currently working on, is ECC capable, but doesn't have ECC RAM. If it
falls over once every couple months, I really don't care :-)

Paul
 
Okay, you are WAY out of my field of knowledge here.

Let's bring things down to basics. How safe is it to add two stick of...

OCZ EL Platinum PC3200
http://www.ncix.com/products/index.php?sku=14504&promoid=1025

....to two existing sticks of...

Corsair CMX1024-3200C2
http://www.corsair.com/_datasheets/CMX1024-3200C2.pdf

....on an Asus A8N-SLI Deluxe
http://www.asus.com/products.aspx?l1=3&l2=15&l3=148&model=375&modelmenu=1

...?

And assuming it's 100% safe, is it - according to you - the best available
option for me, all things considered?
 
ECC is error correcting memory; by storing extra bits (more than 8 bits
per byte), the memory can correct single bit errors and detect multi-bit
errors. Even if you motherboard supports it, you don't NEED it, and
very few PC users buy ECC memory. It's an option, in any case, that you
don't have to buy (and it will cost significantly more than non-ECC
(which I would call "standard") memory.
 
Paul said:
You never stated what the 4GB of memory was for. How can I judge
whether the upgrade makes sense, based on not knowing why you need 4GB ?
Right now, only you have all the info needed to make the decision.
Click to expand...

A Sonar 7-based digital audio workstation (DAW) and very high-resolution
Photoshop work.

If the Corsair is just $8 more, why not go with that? What does the OCZ
offer as an advantage?
 
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