Dual core processors?

Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

Whoever wrote:
Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

There are two things to consider when comparing dual core vs dual cpu.

1) Clock speed. Sometimes the fastest dual core version of a CPU has lower
clock speed than the fastest single core version of the same CPU. This is
because it is easier to get rid of the heat from two separate CPUs with
their own fans than to get rid of the same amount of heat with a single
CPU fan.

2) Memory bandwidht. Every dual opteron motherboard except the most low
end ones have a memory bank for each CPU. This means more memory bandwidth
than when two cores share the same hypertransport bus to the same memory
bank. Xeon motherboards usually have both CPUs connected to the same
memory bank, so here the difference between dual cpu and dual core is not
as big. There might be some very high end intel motherboards that have
different memory banks for different cpus.

regards Henrik
--
The address in the header is only to prevent spam. My real address is:
hc8(at)uthyres.com Examples of addresses which go to spammers:
root@localhost

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

In comp.os.linux.hardware AZ Nomad :
On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

Probably not, as you know Usenet is just a write only medium. ;-)

--
Michael Heiming (X-PGP-Sig GPG-Key ID: EDD27B94)
mail: echo | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 236: Fanout dropping voltage too much, try cutting
some of those little traces

On Sun, 2 Jul 2006, AZ Nomad wrote:

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

Benchmarks on how dual-core processors work when running games are not too
useful...... Pretty much all the major benchmarking sites seem to be
focussed on games. I was hoping for a more informed reply, instead of a
flame -- I guess that shows naivete about usenet.

On Mon, 3 Jul 2006 15:16:51 -0700, Whoever wrote:




On Sun, 2 Jul 2006, AZ Nomad wrote:

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

Benchmarks on how dual-core processors work when running games are not too
useful...... Pretty much all the major benchmarking sites seem to be

There are benchmarks for every kind of application ranging from games,
video processing, databases, etc. Just put the application type in your
search string.

games offer much better predictable PC performance figures than most vendor
originated application base stats.

Besides, if you did use search, you could easily find stats generated from
several sites that offer any number of statistics based on most of the major
(or merely popular) performance measurements applications like SIsoftware's
Sandra. That doesn't even begin to touch the third party sites, like Tom's
hardware and others - that offer excel, SQL or record search based stats.

I have too, a lot of people have gotten too lazy to do anything except ask
some else to collate and provide them with an information package. Some even
have the temerity to complain when its not provided, provided quickly enough
or in the exact form and format they require.

At least you were polite about it. Some people...just refuse to help others
with a little information. Tisk, tisk, tisk....how rude!

"Whoever" wrote in message
caldomain...


On Sun, 2 Jul 2006, AZ Nomad wrote:

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

Benchmarks on how dual-core processors work when running games are not too
useful...... Pretty much all the major benchmarking sites seem to be
focussed on games. I was hoping for a more informed reply, instead of a
flame -- I guess that shows naivete about usenet.

AZ Nomad wrote:

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever wrote:


Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

does anybody know how to find google and use it to search for benchmarks?

Die luftibus no est dispudantum.

Fly them all to their theological place of external PUNishment.

--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

On Sat, 1 Jul 2006 22:02:13 -0700, Whoever
wrote:

Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

In other words, would a 2 x dual-core processor be equivalent to a 4-cpu
machine?

Such information does seem to be left out of all the reviews I've
seen.

Funny that everyone claims that searching is so easy, yet they don't
give any URL's to show how easy it was for them.

assholes

simple minded wrote:
On Sat, 1 Jul 2006 22:02:13 -0700, Whoever
wrote:

Does anyone have any numbers or information on a dual core processor
stacks up to a pair of single core processors?

Results 1 - 10 of about 9,260,000 for dual core versus dual cpu
performance. (0.39 seconds)

http://www.pugetsystems.com/articles.php?id=23

"Conclusion:

As you can see, the move to dual-core is definitely a win for consumers.
Since they are more affordable than dual processor computers, but offer
the same or better performance, they are becoming the standard for
modern computer systems."

http://en.wikipedia.org/wiki/Dual-core

Common Misconceptions

Many people commonly assume that the multithreading benefits of a
dual-core processor will translate into a better user experience while
multitasking. This is not generally true, as many user applications
(such as word processing applications) spend most of their time in an
idle state; a person can't switch contexts faster than a computer. The
improvements in computer responsiveness are generally a function of the
operating system and the application code; many applications are not
pervasively multithreaded since coding multithreaded applications is
generally considered to be very difficult.
[edit]

http://www.vmware.com/community/mess...ssageID=401341

Dual Core vs. Dual processor
Posted: May 17, 2006 8:11 AM in response to: sgunelius
Click to reply to this topic Reply

I wish I had the numbers on hand, but while dual processor "doubles"
your processing power; a second core doesn't have that "doubling"
effect, it is more on the order of 80%.
Unfortunately, a second CPU doesn't double a system's performance;
neither does a second core. There's always some overhead for scheduling
threads and processes among several cores/CPUs - if you're lucky enough
to be running something that's decently threaded. Every CPU socket (on
the motherboard) has a certain available memory and I/O bandwidth; when
we put a multicore CPU in a socket, all cores in that socket will have
to share that bandwidth among themselves. If we put each core in its
socket, it will have all that socket's bandwidth to itself. However,
sockets share bandwidth with each other, and there's where Intel and AMD
implementations are radically different (AMD is clearly superior by
allowing greater parallelism). So, in an Intel system, it's more or less
the same to have a 2-way server with 2 single-core CPUs or with one
dual-core CPU. AMD systems have other kind of optimizations that
mitigate the extra burden of having to share the socket with a second
core. All in all, only the speed and number of cores matters; the
packaging factor (i.e: number of cores per socket) is negligible.

The same can be said for Hyperthreading, in that a second logical
processor won't "double" your processing capability.
Can anyone on the forum post numbers on the increase noted with
dual-core and/or logical processors?
Hyperthreading is radically different: it's a single CPU purporting to
be two different CPUs, in order to capitalize on the fact that,
sometimes, it's able to process two independent instructions at the same
time. This, depending on the code, may allow for an extra 15%-30%
performance improvement, but not more.

As for the licensing, it's strictly a software makers'
strategic/marketing decision; there's nothing "technical" about it. Of
course, this doesn't mean we shouldn't take advantage of it...

http://www.barefeats.com/dualcore.html

http://firingsquad.com/hardware/colf...eron/page7.asp

http://www.pcolalug.org/smf/index.ph...13998#msg13998

http://www.digitalcad.com/articles/v...e.jsp?id=38547

http://librenix.com/?inode=7636

Benchmarks: Dual Core vs. Dual Processor
In this Apples-to-Apples comparison the battle is PowerPC G5 vs. G5 at
2.3 GHz... with interesting results.

The latest Power Macs ship with dual-core 2.0GHz and 2.3GHz PowerPC
G5 processors, as opposed to the two single-core chips in the preceding
models. Apple also added faster DDR2 RAM and PCI Express graphics cards
to the new models, replacing DDR memory and AGP graphics cards. That
change helped the new Power Macs edge past their respective predecessors
with similar clock speeds.

The dual-core 2.3GHz Power Mac fared better than a single-core
dual-processor 2.3GHz model in six of our seven tests.

Apple has tacitly endorsed the dual core model, using two dual cores in
their highest end unit:

http://store.apple.com/1-800-MY-APPL...amily=PowerMac

http://www.processor.com/editorial/a...2p02.asp&guid=

Dual-Core Is No Panacea

Although there's no question that dual-core is the latest trend in
processor development, it is clearly not a panacea for any computing
problem. Reynolds says that some applications may actually run slower on
a dual-core processor vs. a single-core processor. Applications with
many threads may encounter performance problems when faced with slow
threads. Reynolds also notes that dual-core processors may face
performance limitations from poor I/O bandwidth. That is, a processor
must provide an I/O bandwidth that supports the number of threads that
are operating, and some dual-core product proposals just don't show the
necessary bandwidth for efficient dual-core operation.

AMD versus Intel dual core/dual single core differences, related to
memory bandwidth:

http://www.lostcircuits.com/cpu/p4_840/

A veritable boatload of benchmarks he

http://cracauer-forum.cons.org/forum/crabench.html

http://tech.yahoo.com/blogs/null/25

...."Almost everyone will benefit from a dual core machine, and for very
little additional money over a single core machine. Leave the dual
processors for the extreme gamers and the web servers."

*Here is probably the best link:*

http://www.digit-life.com/articles2/...mp-vs-smp.html

" 1. As in case with dual core Intel processors, the dual core
desktop AMD Athlon 64 X2 processor is generally more preferable in terms
of performance than the dual processor system based on an
equally-clocked single-core Opteron. It has to do with the general
conservative nature of server and desktop platforms, which prefer more
reliable but slower memory, as well as with memory access specifics in
Opteron systems, where single-threaded and multi-threaded tasks prefer
different module installations (there is no ideal configuration for any
usage — as always).

2. Building a workstation on dual core Opteron processors is hardly
a universally good idea, as even those applications that profit from two
processors often cannot use a greater number of CPUs (for example,
four). So, the dual core Opteron is mostly a server-oriented processor
(AMD actually positions it in the same way). Unfortunately, we have no
streamlined method for testing CPU performance with server tasks so far,
so we can say nothing about the performance of systems based on dual
core Opteron processors in their element.

3. It's hard to tell whether it's a fault of our motherboard samples
or Opteron memory specifics (or both factors simultaneously), but the
failures during standard tests are somewhat disturbing. However, it just
proves the fact that when you buy a server or a workstation, you should
make sure they are compatible with your software. This recommendation is
actually all-purpose and can be applied to non-AMD systems as well.
Servers or workstations are expensive, and the let's-test-and-then-buy
approach is usually accepted by retailers.

P.S. It seems obvious to us, but we shall publish it anyway in case
somebody has missed it: none of dual core processors as well as SMP
systems can still be recommended for gaming, as no game profits from
more than one processor in a system (probably except for chess . A
single-core processor is always cheaper than an equally-clocked dual
core processor."

In other words, would a 2 x dual-core processor be equivalent to a
4-cpu machine?

Perhaps a better question is "could my application/work {x} benefit from
a dual-dual core machine?"

If you are a gamer: throw down for the fastest single core you can guy.

If you are a home/office/SOHO user, get the fastest dual core chip you can.

It's unlikely that you need a dual CPU system...doubtful you need a
server, or that you do other intense computational work where some
subtle optimizations will help throughput (film, sound, graphics
editing)....if so, you would have a consultant (no jokes here please) to
help spec out an appropriate system.

For either: good name brand memory with a lifetime warranty: Corsair,
Kingston, Crucial, or Micron; get 2 x 1GB, assuming that's enough for
whatever applications you are running. You can install 4 x 1G, but
depending on what OS you are running, not all of that is always seen.
Generally speaking, more memory is better.

If you are looking for speed, get good quality hard drives: a Raptor
for the OS, and a fast Seagate for data.

If you are gaming, spend money on a good graphics card: nVidia seems to
be doing best right now across their product line (but, I have Matrox
and ATI cards here as well, and even some on-board graphics which work
fine).

All is all, it's a balance thing: two fast CPUs on a poor quality
motherboard with cheap no name memory and a 5400 RPM 8 GB hard drive
with on board graphics is going to be painful at best.

Oh, and one more thing: Intel is releasing its new Conroe CPU on July
27 2006:

http://www.hkepc.com/bbs/itnews.php?...me=0&endtime=0

AMD is going to drop prices.

http://www.theinquirer.net/default.aspx?article=32717

http://www.theinquirer.net/default.aspx?article=32666

http://www.forbes.com/technology/200...0628intel.html

http://www.dailytech.com/article.aspx?newsid=2800

* AMD Athlon 64 price cuts will receive price cut up to 30%
* AMD Athlon 64 X2 will receive price cuts up to 50%
* AMD Sempron processors will receive price cuts up to 15%

In conclusion: wait a few weeks; were it up to me, I would go for a
dual core AMD socket AM2 CPU, a good Asus or Tyan motherboard, Corsair
or Kingston RAM, hard drives as above, and your favorite/appropriate
video card. Oh, and don't cheap out on the PSU: get a higher end
Seasonic or PC Power and Cooling unit.

http://www.pcpowercooling.com/home/

Make sure you get enough amperage on the separate rails:

http://extreme.outervision.com/psucalculator.jsp