"Rich said:
This computer I am upgrading will be used for at-home work graphics design
and video editing, and also gaming, which leads to this question...
Using the 875 chipset (ASUS P4C800-E Deluxe) with 2-gigs of DDR memory rated
for DDR500 like the Corsair at DDR500 (250 MHz) JEDEC-standard latency
settings (3-4-4-8), if I don't overclock at all times and decide to run at
200 MHz, will this memory operate if timings set at CL2.0-2-2-5?
Or would I be better off getting less expensive memory 200 MHz at 3-4-4-8 or
lower latency 200 MHz, 2-3-2-6?
Thanks...
As far as I know "clock rate is king". If you can find a way to run the
memory at DDR500 at 3-4-4-8, that is better than running at 2-2-2-5
at DDR400. The thing is, going from 400 to 500 is a 25% improvement,
and the penalty of the greater CAS number is not as great as the
25% improvement due to clock rate.
To buy the DDR500 memory only makes sense if you plan to overclock
via bumping the FSB. You can even overclock without the DDR500
memory, by using the 5:4 ratio between FSB and memory. The difference
is, with the DDR500 memory, you can use a 1:1 ratio between FSB and
memory, and this gives the best memory bandwidth combined with your
core frequency overclock. As you plan to do video editing, maybe
the additional cost is worth it, if video editing is a
money making activity.
For example, you could take a 2.4GHz/800 processor and run it at
3.0GHz/1000, while using your DDR500 memory at 1:1 (or some
DDR400 memory at 5:4 ratio). You could start with a slightly
faster processor, and then overclock past the highest core
frequency in the processor family, but this might require boosting
the core voltage a bit.
To see how overclockable processors can be, consult abxzone.com
and their forums, or look at the cpudatabase at:
http://www.cpudatabase.com/CPUdb
It looks like exceptional processors can go to 3.6-3.8Ghz with
air cooling, so even a 2.8 or a 3.0GHz/800 can be used as a
base for overclocking. (Normally, people overclock 2.4GHz
processors to 3.0GHz, to save money.)
If what you do isn't truly memory intensive, fattening up the
memory is a waste of money. Even some CAS3 DDR400 is good enough.
(That 25% memory bandwidth improvement will buy a lesser number
improvement in application performance, like maybe 8%, so there
has to be a financial incentive behind such a purchase.)
If you don't like my numbers, the only data I have to offer is
this chart for the Athlon and A7N8X board. Here you can see
performance changes while varying the memory timing parameters
and clock rates:
http://www.systemcooling.com/images/reviews/Misc/Overclocking_Guide/matrix.jpg
The situation changes if you plan on using four sticks of memory,
versus running with two sticks. Four stick configurations
are not as tolerant of high memory clock rates, so four matched
LL DDR400 might be a better approach if you want to fill up
the memory slots. One person reported running four sticks at
DDR440, but I don't know how common an experience that is with
P4C800/P4P800 boards. Do some searches on abxzone.com, to see
if there are any more positive experiences with four sticks.
HTH,
Paul
