medico said:
Hi Group,
Have just aquuired an intel motherboard (Intel D975XBX 304 Core 2 Duo
Quad
Extreme Motherboard) and I am now looking for a suitable cpu.
Looking through the intel site I find a stack of suitable cpu's, so I
am now
trying to wade through the list and sort out what is available and at
what
price.
However my problem is:
How do I decide from the stack of info which is the better processor
at the
price.
Has anyone a guide list that they may share.
Thanks in advance to all those that take the time to reply
newbie
I can make it simple for you.
To a first order approximation, the value is proportional to the
core clock speed, times the number of cores present. (Assuming the
architecture of the things being compared, is the same. No cheating,
by comparing a Pentium4 netburst processor, to a Core2 for example.)
For example, if you had a quad 2.4GHz Core2 and a dual 3GHz Core2,
the first one is worth "9.6 units", and the second "6 units".
If you are interested in overclocking, or view overclocking as
part of the value equation, then various people on these groups
will suggest things they've found to be good value. In that
case, it would be a matter of how far a particular processor
overclocks, versus its purchase price. So overclocking versus
not overclocking, is an important factor in the decision of
what to buy. Overclocking starts with "value processors",
preferably with a lower FSB, and overclocking them to higher
speeds.
As an example, a thing like this would have headroom. It is
a Core2 processor in 45nm technology, FSB1066 leaves room for
overclocking (potential limit these days is about FSB2000 with
the right motherboard). So this might be something an overclocker
would buy - cheap, with plenty of potential. I don't keep track
of the latest and greatest of these (I'd only get interested,
on the purchase day). This would be a snap, to run at 3GHz core
speed, when an E8400 costs more.
E7200 Wolfdale 2.53GHz/FSB1066/3MB L2 Cache $131
http://processorfinder.intel.com/details.aspx?sSpec=SLAVN
The first review I see here, mentioned it ran at 3.8GHz. So
the purchaser got a lot more than he might have got with an E8500.
http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16819115052
To use multiple cores, requires a discussion of multithreading
or multitasking.
To use four cores simultaneously, to 100% loading on each,
requires software which is multithreaded, and spreads the
load well on each thread. Some games are multithreaded,
but one core ends up with most of the computing load,
leaving the others at perhaps 30% or so. The gains of
using a quad in that case, are not as clear or apparent.
(In this case, we're running a single gaming program, and
trying to get the best from our new processor.)
There is also task level parallelism. For example, doing
a DVDShrink, a batch of POVRAY work, editing a Microsoft
Word document, and playing a CD, might use one core each.
So a person who multitasks, and runs batch oriented computing
tasks, will get some benefit from multiple cores. But it
is pretty hard for a human to keep the thing fed.
Some multimedia applications can chop up a problem, into
chunks, and do a chunk on each core. Photoshop has some
filters that are multithreaded, so those filters will
run faster on a quad. But the other filters are single
threaded, so it really depends on which filters you use
the most, as to whether it is better to get a quad core
or not. Multimedia programs like Photoshop, have better
odds of loading the cores equally, for better overall
utilization (more of those "9.6 units" get used).
(It is actually pretty hard to get useful information
about program design, and which programs work well on
current processors. I consider this a failing of the
companies writing the software.)
So that is quick summary of considerations. You can also
use things like the Tomshardware benchmarks, but the
benchmarks are skewed towards multithreaded tasks,
and can be deceptive. It requires an experienced eye, to
make the best use of the Tomshardware charts - putting
this another way, there is plenty of room for improvements
in the benchmarks chosen. The charts would be better, if
they were prepared from a potential user's point of view,
and not a site sponsor. And that is why I wrote the above,
because while I could have just given this link, it would
leave the wrong impressions. (The iTunes benchmark, is,
as far as I know, the only single threaded benchmark on
the charts. A lot of the software you currently own,
will be single threaded, and iTunes might actually be
a better predictor of how it works for you, than some of
the other benchmarks.)
http://www.tomshardware.com/charts/processors/3d-studio-max-9,369.html
If you're primarily a "multimedia guy", then the quad
is more of a winner for you than a dual. For a lot of
ordinary tasks, a faster dual might be the right answer.
Overclocking a quad, to the speed of that faster dual, covers
both possibilities.
Paul
