pc2700 cl2.5 or pc2100 cl2?

narf

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i'm currently in the process of upgrading my pc but since i know nothing about hardware i thought i'd get some advice from the experts ;). my question is for an athlon xp 1800 which would be the better choice,

184Pin DIMM PC2100 DDR RAM Non-Parity CL2
or
184Pin DIMM PC2700 DDR RAM Non-Parity CL2.5

thanks :)
 

bum_jcrules

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I would suggest the PC2700. If it is a good brand, then it should be able to handle the 2.0 CAS setting. It is only a half clock cycle difference anyway. The main reason I suggest the PC2700 is the fact that it will delay your next upgrade on memory. And like I said, if it is a good brand, it should be able to handle the more demanding CAS 2.0 timing delay. It isn't much of a difference between 2.0 and 2.5. <A HREF="http://www.tomshardware.com/mainboard/02q2/020507/timing-04.html#maximum_memory_transfer_rate_sisoft_sandra_2002_pro" target="_new">Look here at a test that Tom's Hardware did reguarding this issue</A>.

<b>"Sometimes you can't hear me because I'm talking in parenthesis" - Steven Wright</b> :lol:
 
G

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i had already read this article but i haven't found the benchmarks really clear.

Although Windows XP is managing to become established as the standard operating system, the dynamic memory administration is a roadblock when it comes to getting exact benchmark results. In evaluation of memory performance, the subtlest of nuances are also important, therefore we turned to Windows 2000 Professional.

Explanation: the charts show you results that are labeled "Slowest" and "Fastest." The following table shows you the settings we chose:

Fastest Slowest
Act to Precharge 5 7
RAS-to-CAS 2 3
RAS Precharge 2 3


The differences in the implementation of these three parameters are so small that the benchmarks are not able to give us results that can be interpreted, due to the measurement tolerance. Therefore, we ran all three values with the fastest and the slowest possible settings, each with CL2 and CL2.5.
a bit weird those requisites, no?


<i> :smile: I like THG Interactive, Inc.</i>
 

Booky

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I would get PC2700 with CL2. It isn't that much more for them and would deffinetly help you delay any future upgrades some. If you read the artile posted by someone earlier in this thread I feel you will see the importance of CL2 over CL2.5 or CL3.

Crap, all the good ones are already taken.
 

bum_jcrules

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Yes the article is confusing. However the fact still remains that the difference between a CAS timing delay of 2 cycles verses 2.5 cycles is miniscule. The differences between what you quoted...

Explanation: the charts show you results that are labeled "Slowest" and "Fastest." The following table shows you the settings we chose:

Fastest Slowest
Act to Precharge 5 7
RAS-to-CAS 2 3
RAS Precharge 2 3
... is an additional 4 cycles. Now take PC2700 that is running at around 166MHz. (500/3 to be exact. I'll use 166MHz for illustrative purposes.) That is 166,000,000 cycles per second. If you add the difference between the Precharge settings (2 cycles), the <b>R</b>ow <b>A</b>ccess <b>S</b>trobe Precharge (2 Cycles), the RAS to CAS delay {1 Cycle) and the <b>C</b>olumn <b>A</b>ccess <b>S</b>trobe (0.5 cycles). The total is 4.5 cycles. That difference is 4.5 cycles out of the 166,000,000 cycles per second. That is one tiny, tiny, really, really, really, small number. (4.5 cycles /166,000,000 cycles per second = 0.0000000271 seconds. If I used 166,666,666.6667 that number would be even smaller. 0.0000000270 seconds. <font color=red><b>That is about 3 tenths, ...of a millionth, ...of one second</b></font color=red>. hehe)

So you can see, that the difference in the timing of your memory will not be that significant. Using faster memory would be a better improvement than better timing settings on the same memory.

Back to you...

<b>"Sometimes you can't hear me because I'm talking in parenthesis" - Steven Wright</b> :lol:

EDIT:

It seems to me that a lot of people here get their panties in a knot about this issue. The most aggressive timing setting don't matter as much when the clock speeds are so fast. Back in the day of Fast Page, EDO, Burst EDO, or even PC66 those timing settings had more meaning. However with DDR there ate two bits per cycle and the speeds are faster. So to say it clearly, Timing between CL2 and CL2.5 doesn't really matter!!!
 

bum_jcrules

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:smile: As Nick Burns might say..."Your Welcome!"

But I say "Thanks. Your welcome, anytime. Anything I can do to increase the knoledge base here at THGC."

<b>"Sometimes you can't hear me because I'm talking in parenthesis" - Steven Wright</b> :lol: