"Barry" said:
Paul,
Once again thanks very muchly for your earlier reply.
I spent several hours at Abxzone.com reading several very looooong =
threads on PC memory. To be honest, I don't understand a lot of what =
was written but it DID help somewhat.
I replying again since I'm about to buy the mobo, ram, graphics card, =
etc. etc. and I just want to know that I'm getting the right CPU/RAM =
combo for my needs.
To voice the bleeding obvious, I've got 2 choices : To OC or not to OC.
From what I read, if I want to OC then my best choice would be to buy a =
2.4C P4 and the fastest memory I can afford. Particularly PC3700 or =
PC4000.
On the other hand, if I DON'T want to OC then buy the fastest P4 I can =
afford and "normal" PC3200 ram.
I also gathered that LL ram is far more important for a AMD XP than it =
is for a Intel P4.
Given my lack of knowledge of "all things OC'ing", I'll take the NO =
OC'ing option. I know it may not be difficult but I simply can't afford =
the chance that I might "burn" the CPU/ram/mobo by making a silly little =
mistake.
In your reply above you suggest that CAS3 ram is just fine. I presume =
your are referring to Kingston Valueram or similar.
However, after reading the threads at Abxzone.com I'm still not clear =
whether buying say, CORSAIR PC3200LL, will give me any better =
performance at standard FSB/etc. and even if it does, how much?
Thanks very muchly
Barry...
First off, if you want the last percentage point of performance,
I'm not the guy to ask. There are plenty of people on Abxzone
who sweat the details, and if you read enough of their tests,
you might get some good ideas as to what to do. (The only thing
I don't agree with, is running 2.5V memory at 3.3V. That is
like putting sugar in your gas tank...)
For a general overview, there is this article. While many people
will bemoan the fact that the article is published on Tom's, it
is better than nothing, and faster than reading 10,000 posts
on Abxzone.com.
http://www.tomshardware.com/motherboard/20040119/index.html
The thing about some of your overclocking choices, is they
cost money, and only work well if you use them for their
intended purpose. Take the "PC4000" memory, for example.
It excels at high memory clocks, and you are balancing the
25% improvement, going from DDR400 to DDR500, versus the
fact that the memory runs at 3-4-4-8 versus 2-3-2-6 or the
like. If you bought the PC4000, and didn't overclock, the
solution would be inferior to buying PC3200 memory (as
PC4000 doesn't magically become LL memory when the clock
runs slower). So, if you are "going for it", then you have
to stick with it.
If you buy PC3200 memory, you can run CPU:FSB at 1:1 for
stock frequency operation (FSB800 CPU and DDR400 dual
channel memory). Nothing is stressed. If you select the
5:4 ratio, you can do some core overclocking and extract
more performance from the processor than normal. The
FSB runs at FSB1000 when CPU clock is 250MHz and the
memory is still running at DDR400. So the combo of PC3200
LL memory and 875/865 available ratios, gives you some
options. (Also keep in mind, you have to select the
processor based on your ram strategy - a 2.8*1.25
overclock = 3.5GHz, which looks to be achievable
on the cpudatabase web site.)
If you had asked me this question maybe 4 months ago,
I'd have been telling you that PC4000 was the best
performance wise. But there are some dissenting voices
over on Abxzone right now, who are getting _almost_
as good results from using LL memory. This has left
me, to say the least, very confused
I guess I would say, if you are happy to have a fast class
of machine, without splashing too much cash around, then
some ordinary CAS3 is good enough. Buy the PC3200LL if
you want some options, being aware that as a result,
you end up with a processor that runs at either 2.8GHz
or 3.5GHz. (Same ideas apply if you choose some middle
ground, like the PC3500. That would leave room for a
slightly higher top end, and might require better than
just air cooling for the processor.) Buy the PC4000 if
you plan to leave the processor at 3.5GHz all the time,
and have applications that are very memory intensive,
like Photoshop.
Keep in mind, that the improvement in memory bandwidth,
isn't reflected to the same degree in overall performance.
A 10% improvement in memory bandwidth might buy you 3%
shorter execution time in what you are doing. Exceptions
are Photoshop or other applications with a heavy emphasis
on memory - if you spend most of your time doing one
application only, then pick the solution that is best
for that one app.
As for "burning the mobo", the P4 has thermal throttling,
so isn't likely to disappear in a blaze of glory. My rule
of thumb is, you can overclock to at least the highest
frequency that the family runs at - the processor dice
are all the same, and are binned for operation at 2.8, 3.0,
3.2, 3.4 etc. So running at 3.5 isn't a big deal.
If you have to raise the voltage of a part significantly,
in order to have a stable overclock, that does imply an
extra stress. You do occasionally read of people who have
to back off on their overclock, because the processor
gets "tired", and I take this to be a speed fault caused
by electromigration. This is why I don't recommend just
randomly increasing the voltage. On the DDR DIMMs, 2.6
to 2.8 is probably not too hard on the DIMM, but higher
than that is asking for trouble, as some portions of the
circuitry in the DRAM is regulated by an internal voltage
regulator, and the extra voltage is just turned into
unnecessary heat (heat which in fact, slows the memory
down!). I think using a little common sense, you aren't
going to affect the 3 year practical life of the mobo
before upgrading again.
HTH,
Paul
