General Memory Question

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PB

Hello, again, all.

I have posted recently with questions regarding my A8V Deluxe board and
received some good advice. I have a more general question to those out
there who understand the myriad memory settings and their effects.

Given the choice to run 1 GB as 2x512 on the A8V Deluxe, no
overclocking, which settings would give the better performance, on
average, for general use and a little gaming?

2.5-4-4 as the product I own here:
http://www.newegg.com/Product/Product.asp?Item=N82E16820146219

or

3-3-3-8 as the other pair I own here:
http://www.newegg.com/product/product.asp?item=N82E16820146299

Thanks for the input to [my] memory.

p00lb0y
 
PB said:
Hello, again, all.


Given the choice to run 1 GB as 2x512 on the A8V Deluxe, no overclocking,
which settings would give the better performance, on average, for general
use and a little gaming?

2.5-4-4 as the product I own here:
http://www.newegg.com/Product/Product.asp?Item=N82E16820146219

or

3-3-3-8 as the other pair I own here:
http://www.newegg.com/product/product.asp?item=N82E16820146299
Click to expand...
I'm guessing to some extent. This number will be between 2.5 and 3.0 and
lower is better. "CL" or something.
 
I'm guessing to some extent. This number will be between 2.5 and 3.0 and
lower is better. "CL" or something.
Click to expand...

The first one.
Cas Latency is the first and most significant timing.
 
Those are the numbers reported on the product page link. Please
expand on your reply so as to help me understand your explanation.

PB
Click to expand...

O.K. A small joke :-)

Well, I think 3338 timing is not modern. It should be 2225!
If you OS accesses, say 235KB of data you would have to wait 3338
instead of 2225 to load. Even if the specs are telling that your
wonderful new supermodern chipset is capable of tranfering 4GB per sec.
I have 800MB per sec but my 786MB of MainRAM would not load it in one
sec. :-).

I know that the specs are a theoretically speed (and praktical). But
Praktical is windows or linux, Beos and consorts and they transfer kb´s
and MB´s, but 3 or more GB´s per second!! NO.

Other, I have here 2220 timing and load mb Data (300KB-2.5MB) faster
than a AMD2700XP with 333MHz DDR RAM (not dual channel).
But I have 103MHz FSB and 1100 less of CPU MHz (1083 real MHz P3-S).



Best Regards,

Daniel Mandic



Best Regards,

Daniel Mandic
 
I'm guessing to some extent. This number will be between 2.5 and 3.0 and
lower is better. "CL" or something.
Click to expand...

Google "ram speed settings" for some explanations. The numbers you
are refering to represent the number of clock cycles required to
access or activate the various rows and columns of the RAM modules or
memory banks. But there is more to it than that and requires you to
understand just how memory works before you can decide if super fast
settings will appreciably affect the performance of your particular
setup and programs. The ability to quickly transfer large amounts of
data may not be necessary for your end use. If you have a quality, and
fast processor you will only need fast RAM modules if your computer
will be computing a lot or encoding video. For any other application,
slower RAM is fine.

Tom's Hardware has a good primer for understanding these numbers
http://www.tomshardware.com/motherboard/20040119/

Here is a quote:
"Information is stored by first separating the memory area into rows
and columns. The capacity of the individual chips determines the
number of rows and columns per module. When several arrays are
combined, they create memory banks.

The chips are actually accessed by means of control signals such as
row address strobe (RAS), column address strobe (CAS), write enable
(WE), chip select (CS) and several additional commands (DQ). You also
need to know something about which row is active in the memory matrix
at any given moment.

In today's computers, a command rate is defined in BIOS - generally
1-2 cycles. This describes the amount of time it takes for the RAS to
be executed after the memory chip has been selected.

The memory controller selects the active row. But before the row will
actually become active so that the columns can be accessed, the
controller has to wait for 2-3 cycles - tRCD (RAS-to-CAS delay). Then
it sends the actual read command, which is also followed by a delay -
the CAS latency. For DDR RAM, CAS latency is 2, 2.5 or 3 cycles. Once
this time has lapsed, the data will be sent to the DQ pins. After the
data has been retrieved, the controller has to deactivate the row
again, which is done within tRP (RAS precharge time).

There is one more technical restriction - tRAS (active-to-precharge
delay). This is the fewest number of cycles that a row has to be
active before it can be deactivated again. 5-8 cycles are about
average for tRAS."
 
I'd like to know how you got a zero stuffed in there, Im running kingston
hyperx ddr400 at 2.5-2-2-6 which is about its limit(on and A64 board).
 
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