Is DDR2 slower than DDR?

  • Thread starter Thread starter Michael C
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Michael C

I bought a laptop recently and someone (who was keen to find any possible
faults with it) said it would be slower because it has ddr2. Is there any
truth to that? The ram is CL4 where if I'd got ddr it would have been CL2.5.

Thanks,
Michael
 
I bought a laptop recently and someone (who was keen to find any possible
faults with it) said it would be slower because it has ddr2. Is there any
truth to that? The ram is CL4 where if I'd got ddr it would have been CL2.5.

Thanks,
Michael
Click to expand...

DDR2's higher latency is signicant, often moreso than the
higher bandwidth. This is with CAS4, newer DDR2 is CAS3 and
thus a little faster. Benchmarks will bear this out for
specific uses but overall a user might not notice it... or
in some cases even benefit from the higher bandwidth.

DDR2 also uses a little less power, maybe 30%, I don't
recall the specfics. That alone might be desirable for
laptop use- frankly I'd take a slower laptop if it ran for
twice as long inbetween battery charges.

The most significant bottlenecks in a laptop are often the
hard drive, video card if gaming, CPU if it overheats and
throttles back to lower speed. It may not matter on your
specific laptop which memory type is used, you'd have to
benchmark it in your particular, most demanding uses to draw
a viable conclusion. Some DDR2 is now hitting CAS2.5, you
might just keep the laptop and if someday you decide to
upgrade the memory then determine whether the
mainboard/chipset/bios supports lower CAS and get that ...
and it will be cheaper in the future than it is today.

I suppose my conclusion is that if this is a very high end
laptop, CAS4 DDR2 is out of place in it, it should've had
DDR1 or CAS3 DDR2. Otherwise DDR2 might be a sign that
platform in general is newer and might be more full-featured
and possibly have some other benefits as well.
 
"Michael C" said:
I bought a laptop recently and someone (who was keen to find any possible
faults with it) said it would be slower because it has ddr2. Is there any
truth to that? The ram is CL4 where if I'd got ddr it would have been CL2.5.

Thanks,
Michael
Click to expand...

From desktop benchmarks, DDR2-533 roughly matches DDR400 in performance.
These are probably not the most applicable benchmark articles,
but they'll give you some idea. Synthetic benchmarks, such as
a memory bandwidth benchmarks, show larger differences than would
real application benchmarks, but a memory bandwidth benchmark
might be the only way to see a difference (kinda like using a
magnifying glass :-) ).

(Compare third and fifth lines in the table. A 915 board tested
with DDR2-533 and DDR400 memory respectively.)
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2088&p=16

915 DDR (yellow) versus 915 DDR2 (dark yellow). There is
little difference at the application level. Not directly
comparable to your system, as "non-enthusiast" configs might
be CAS3 for PC3200 and 4-4-4-12 for the DDR2-533. They
use memory with tighter timings here.

http://www.anandtech.com/mb/showdoc.aspx?i=2293&p=29

Some more results here:

http://www.xbitlabs.com/articles/chipsets/display/p4-fastest_5.html

I would say it is hardly worth fighting over.

Paul
 
kony said:
I suppose my conclusion is that if this is a very high end
laptop,
Click to expand...

It's not, it's one of the cheapest I could find without going to the real
low end laptops. Although I couldn't see much benefit going to laptops twice
it's cost.
CAS4 DDR2 is out of place in it, it should've had
DDR1 or CAS3 DDR2. Otherwise DDR2 might be a sign that
platform in general is newer and might be more full-featured
and possibly have some other benefits as well.
Click to expand...

I'm not using it for any real work or for playing games so it's unlikely to
be a problem, I'm more curious than anything. I think quantity is going to
improve performance more than speed anyway.

Michael
 
The latency of DDR2 is slower, but the rated data transfer speed is faster
than DDR. The bottom line is that
DDR2 is somewhat faster, but not alot.
 
It's not, it's one of the cheapest I could find without going to the real
low end laptops. Although I couldn't see much benefit going to laptops twice
it's cost.
Click to expand...

Then be happy you got a modern laptop instead of a rehashed
older tech board.
I'm not using it for any real work or for playing games so it's unlikely to
be a problem, I'm more curious than anything. I think quantity is going to
improve performance more than speed anyway.
Click to expand...

Well for casual/typical non-demanding uses it won't matter
at all which memory it had. Reviewers and spec-geeks like
to make mountains out of molehills.

yes if the system has a memory deficit it will help far more
to add some... I'd have minimum of 512MB for typical WinXP
uses.
 
kony said:
Then be happy you got a modern laptop instead of a rehashed
older tech board.
Click to expand...

I'm happy enough with it.
Well for casual/typical non-demanding uses it won't matter
at all which memory it had. Reviewers and spec-geeks like
to make mountains out of molehills.

yes if the system has a memory deficit it will help far more
to add some... I'd have minimum of 512MB for typical WinXP
uses.
Click to expand...

I bought a 1 gig chip to give it 1.25 gig but when I realised it had dual
channel memory I ordered another 1 gig chip. I would have got a pair of 512s
if I thought about it first but memory is cheap these days :-)

Michael
 
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