Quad/Dual Core Duo Questions

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Hey all,

I understand most of the basics about hardware, like DIMMs and FSB, and
HD/RPM, caches, etc. and this is dangerous, especially when I decide to
build my own computers, lol.  Anyways, here's my tale and questions.

I decided about six months ago to "upgrade" my computer.  I thought I
was in a 89' buick compared to what I could be in.  And the buick, aka,
my system, was actually pretty good.  2GB RAM, 3.2 GHz Pentium with HT
(< this is important later), and a few too many harddrives.  So trying
to get in gear with teh times, I decided to get a new motherboard, new
harddrives (using SATA inplace of my IDE mess), and the crown jewel, a
2.33 GHz Dual Core Pentium.  Now, I had done my research on HT versus
Dual Core, and I was convinced that I was going to see a nice biiiiiig
bump in performace, especially that my FSB was huge compared to the old
FSB, and my RAM had better ratings than before.

So I spend two weeks putting the thing together, working out the bugs,
this and that.  And when its all said and done, it runs like molasses.
My 3.2GHz w/HT ran WAAAAAYYYY better than the dual core.  I am soooo
ticked at myself.

So, here are my questions:  

One, what did I do or think wrong..... and what should I know now that
I should have known before I bought the Dual Core?

Two, The Dual Core Pentiums come in three (or four, maybe) flavors.  Ya
have your Dual Core, Dual Core Extreme, and then Quad Core (and possibly
Quad Core Extreme sometime soon).  Is the quad core simply a dual core
with HT?  or is Dual Come Extreme using HT along with its unlocked
ratio?

Three, should I simply forget that there ever was a thing as HT? or do
you think Intel is going to be using it, or is using it someplace in the
future?



Re: Quad/Dual Core Duo Questions

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What operating system are you using? If your new pc runs Vista then it will
run "like molasses" regardless of the hardware. (Hopefully it will be better
when SP 1 comes out.)

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My understanding is that Quad core is 4 cores, so its not dual core with HT.
HT is a technique for getting more out of each core by letting the
instruction pipeline work on instructions for other threads. Can't answer
the rest, sorry.

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HT always seemed quite a clever idea to me, but it does seem to have
disappeared from the promotional literature. I've no idea what its future
is, but it would seem a shame if it has no place in the future.
--
Brian Cryer
www.cryer.co.uk/brian



Re: Quad/Dual Core Duo Questions


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Not at all -- Hyperthreading was a hack for an insanely poor processor
design in the first place.

Unless we ever see a stupidly long pipeline like the P4 in the future,
HyperThreading will stay buried as a bad memory.

Re: Quad/Dual Core Duo Questions

 ??>> HT always seemed quite a clever idea to me, but it does seem to have
 ??>> disappeared from the promotional literature. I've no idea what its
 ??>> future is, but it would seem a shame if it has no place in the future.

 D> Not at all -- Hyperthreading was a hack for an insanely poor processor
 D> design in the first place.

 D> Unless we ever see a stupidly long pipeline like the P4 in the future,
 D> HyperThreading will stay buried as a bad memory.

SMT is widely used to hide memory latencies -- when one thread is blocked
waiting for memory operation (cache miss), another thread gets executed.
this gives significant performance boost on some workloads, and is used in
high-end processors like POWER, Itanium, UltraSPARC. especially in
UltraSPARC T2 -- they run 8 threads per core, have very small cache, and
beat any other processor in performance-per-mhz factor on webserver
workload.

HyperThreading is an extended form of SMT -- it works not only on cache
misses, but in general course, allowing to use execution units
simultaneously. probably other processor architectures doesn't need this
much -- they don't have lots of spare execution units, or it's not worth
complexity. but it's not totally different -- on UltraSPARC T2 one thread
can run expensive FPU operations while other do simple arithmetic.

there are rumours
(http://www.intel.com/pressroom/archive/releases/20070328fact.htm ) that
Intel is planning to return some form of SMT on desktop processors, but it's
not clear if that would be mere SMT on cache misses, or HT sharing execution
units..



Re: Quad/Dual Core Duo Questions

ldiaco wrote:
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To eliminate any confusion about what you bought, you could quote a
model number, like E6600, E2180, or even an SLxxx code (printed on the
processor box). The thing you bought, could be a Core2 family processor.
For example, it might be an E6550.

http://processorfinder.intel.com/List.aspx?ProcFam=2558

The Core2 2.33GHz, you'd multiply that by 1.5x to 2x, to get some idea of
its "Pentium 4 equivalent" speed. It should feel a little faster
than what you had. And not molasses. More like 3.5 to 4.5GHz or so
in P4 equivalents.

In the past, I've run into a couple people, whose systems seemed to be
stuck at the low multiplier. With EIST (equivalent in its way, to
Cool N' Quiet on AMD), the multiplier changes as a function of system
load. Now, I never did find a definitive step that was missing in their
build. The builders eventually concluded it was fixed, but since they
changed so many things at once, they lost track of what fixed it.

You can use RMClock, to monitor the system. RMClock is supposed to be
able to monitor for throttling, if it is present. I don't really like
the graphical output, but it is better than nothing.

http://cpu.rightmark.org/download.shtml
http://cpu.rightmark.org/download/rmclock_230_bin_upd1.exe
(Screen shot)
http://www.notebookforums.com/attachment.php?attachmentid=8955&stc=1&d=1143767059

"Molasses" can come from a number of things. For example, say your
hard drive was running in PIO mode. The processor would waste a lot
of cycles, any time a file is referenced (since it would use polled
transfer). The bandwidth would be limited (4MB/sec to 8MB/sec).
Programs would be slow to load, but fast once started. You can
test with HDTach or HDTune, and get some idea of the actual speed.
My disk speed ranges from 60MB/sec to 40MB/sec sustained, from the beginning
to the end of the disk. More modern drives manage 70MB/sec or a
little more, in sustained performance. The performance graph
should be a curve - a flat line means cable/interconnect trouble.

Now, if you were to test with SuperPI 1.5 or something similar,
that would spend a good deal of its time using nothing but
processor and memory. Comparing the old system to the new system,
would then give an idea if the CPU and memory was the limitation.
Just the "feel" of the system, may not be narrowing down where the
problem is. (On the machine I'm typing on, SuperPI 1.5 will do the
1 million digits test in 50 seconds. It became that slow, after
I added my antivirus software. I think I might have had maybe
45 seconds at one time, before the antivirus was added. Just if you
want to compare. SuperPI is single threaded AFAIK. My system is a
Northwood P4 3.15GHz/FSB900/DDR450 dual channel. A highly overclocked
Core2 can do the same benchmark in sub 10 seconds, to give some idea
of how good it can be. So my system is 5x out of date.)

http://www.xtremesystems.com/pi/index.php (see super_pi_mod-1.5.zip)

The multiplier is one issue. Processor throttling (CPU instruction rate
drop, to try to stave off overheating), is another mechanism for
losing performance. You want enough cooling, to stay below 70C. About
65C to 70C, is where some of the newer processors start to throttle.
The cooling solution should stay clear of those kinds of temps, in
order to get 100% of the goodness.

Keep the RMClock window open, then run SuperPI, and watch the graph
while it runs.

You can also have a look through this thread, but first I'd prefer
to see you get a handle on exactly what is slow, before going
crazy with unrelated fixes.

http://forum.notebookreview.com/showthread.php?t=60416

    Paul

Re: Quad/Dual Core Duo Questions

Somewhere on teh intarweb "Paul" typed:


[snip]

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Really? Sub 10 seconds? Wicked!

My E4500 @ 3.3GHz takes 17 seconds to calculate 1M.

Oh, and yes, it *is* single-threaded.

Cheers,
--
Shaun.



Re: Quad/Dual Core Duo Questions

Somewhere on teh intarweb "Paul" typed:


[lots of snippage]

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Paul, will you do me a favour please? Start SuperPi and go to 'About' and
tell me the version number. I downloaded a version that says 1.5 but when
unzipped and checked in 'About' it says "ver 1.1". Also the txt document
with the package says ver 1.1e.

Thanks.
--
Shaun.



Re: Quad/Dual Core Duo Questions

~misfit~ wrote:
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Well, that program has a pretty long history. Notice the date is also
screwy, and says 1995 ? The thing is, I don't think source is available.

Here is the history of the 1.5 version (that says 1.1e in the About)...

*******
http://www.xtremesystems.org/forums/archive/index.php/t-54389.html

    "snq                                       03-05-2005, 12:37 PM

     There is no source. This mod was done with a hex editor and some asm tools.

     No, I'm not kidding :)"
*******

That should explain the mix of old and new. When you're cooking up hot
assembler code, who is going to waste time changing text strings :-)

    Paul

Re: Quad/Dual Core Duo Questions

Somewhere on teh intarweb "Paul" typed:
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Thanks for that. I just wanted to check I was using the latest version as
the only place it says 1.5 is the zipped file.

Cheers,
--
Shaun.



Re: Quad/Dual Core Duo Questions

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Per core, I don't think there's much performance difference between your
old and new processor.

I'd running a duo core at 2.4Ghz and compared to a 3.2 HT, the duo core was
noticably faster but I didn't do a real one core cpu test.
I just want to say that it felt much faster right out of the box.

Most programs are not optimized for multi-threading.
Those programs are running on just one core so they don't get any advantage
from the other cores.
You should notice an improvent when running several somewhat cpu intensive
programs at once.

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The dual core processors (both normal and extreme) are 'true' dual core,
meaning: an optimized design for two cores.

The quad core processors (again, normal and extreme) are two dual cores
merged together in one package.
Some say this isn't 'true' quad, other say: who cares!

Anyway, quad cores have four real cores while hyperthreading is just a
pipeline 'trick' to get a bit more processing power.

Extreme processors (both dualcore and quadcore) have an unlocked
multiplier.
All conroe processors can decrease the multiplier.
Only the extremes can increase the multiplier.

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Yes, as far as I know, hyperthreading is gone.
Maybe a part of it is still used for optimization, don't really know.

One other advantage of conroe compared to pentium:
conroes can be hugely overclocked.
You can easily increase your FSB and get the processor running
at 2.6 or 2.8GHz.
Just make sure your memory can handle the FSB and your cpu
cooler is up to the task!
(With good cooling you can get much higher, 3.0 or even 3.2
is do-able)

I don't know why your system runs a lot slower than your previous
system.

My guess is there is something wrong with your setup.
How is your harddrive performance?
If you copy a file from/to your harddisk, is your cpu usage ramping
up to 40% or more? If that is true, you might have a problem with
an IDE device and since the harddisk is accessed a lot, your whole
system will suffer.

The same for graphics drivers. When you drag a window, do you get
a smooth update or is everything very sluggish?


Hope this helps.
Marcel



Re: Quad/Dual Core Duo Questions

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I assume molasses is/are bad - never heard of it/them?

Either I am missing something, you have phrased your question badly, or you
really have upgraded from a 3.2 P4 to a 2.33 P4 with 2 cores and you are
wondering why it is slower??? 3.2GHz down to 2.33GHz = slower! This is not
an upgrade!

You don't tell us the model of the new CPU. I suspect you have actually
bought a 'Core 2 Duo' chip, but you state it to be a P4 dual core. A Core 2
Duo at 2.33 GHz (probably an 'e6600') should be faster than the 3.2GHz P4 at
most tasks.

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You should have known what processor you were buying and read performance
tables comparing the old and new processors. TomsHardware.com has loads of
these.

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P4s and Pentiums, then Dual Core P4/Pentiums went out ages ago. They were
replaced by Core Duo about 18 months ago, then superceeded by the Core 2 Duo
about 12+ months or so ago. The latest Intel processors are called Core 2
Duo and Core 2 Duo Quad. If you have really bought a Dual Core P4 at
2.33GHz, then you have bought a 3yr old processor. It will be slow compared
to the P4 at 3.2GHz that you had before.

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Forget it - Dual and Quad cores are genuine multi-processor units, HT simply
used spare clock cycles on a single processor to 'make out' that there were
two.



Re: Quad/Dual Core Duo Questions

 G> P4s and Pentiums, then Dual Core P4/Pentiums went out ages ago. They
 G> were replaced by Core Duo about 18 months ago, then superceeded by the
 G> Core 2 Duo about 12+ months or so ago. The latest Intel processors are
 G> called Core 2 Duo and Core 2 Duo Quad.

wrong. Intel sells low-end core2s having"Pentium" brand on them.

e.g.:
Pentium Dual Core; E2160; 1.8GHz; 1M cache; 800MHz; LGA-775 box; INTEL; PN:
E2160

it has clock speed similar to Core 2 Duo E6300, but twice less cache and 800
MHz instead of 1066 MHz FSB.
i had no experience with such chips, but people say they are fine and can be
really good with overclocking. cache and FSB are not always useful, indeed..

there are also cheapest models called "Celeron" -- they have only 512 KB
cache and one core.



Re: Quad/Dual Core Duo Questions

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Fair enough, but is there a 2.33GHz Dual Core Pentium for sale at the
moment? This is the chip he has put in his system. I still think he means a
Core 2 Duo and probably an e6600, but until he comes back with more info we
can't help!



Re: Quad/Dual Core Duo Questions

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No, the fastest Pentium Dual-Core is the E2200 at 2.2GHz (not 2.0GHz
like I said earlier..)

The only current 2.33GHz Intel Dual-Core CPU's are the Core 2 Duo
E6540 and E6550

Re: Quad/Dual Core Duo Questions


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A Dual Core Pentium is just a P4 with 2 cores.  What you did was the
equivalent of going from a 3.2 GHz P4 to a 2.33 GHz P4. The dual core
would only show a performance gain in a multithreaded application.
On the other hand a 2.33 GHz Core 2 Duo even running single core
applications would leave the 3.2 GHz P4 in the dust.  The reason is
that the Core 2 Duo performs more instructions per clock cycle than
the P4.



Re: Quad/Dual Core Duo Questions

 l> So I spend two weeks putting the thing together, working out the bugs,
 l> this and that.  And when its all said and done, it runs like molasses.
 l> My 3.2GHz w/HT ran WAAAAAYYYY better than the dual core.  I am soooo
 l> ticked at myself.

i'm pretty sure you wouldn't notice CPU speed in "normal" applications
unless it's really *very* slow.
1 GHz is enough.

so, can you please tell us what you do and why do you think it's slow?

probably you have problems with other components, or problems with CPU --  
it's better to run diagnostic utilities to see what happens

 l> One, what did I do or think wrong..... and what should I know now that
 l> I should have known before I bought the Dual Core?

differences should be very subtle -- you will notice them only on heavy
tasks such as video/audio encoding, rendering etc. probably in some games..

i've myself switched from Pentium4 3 GHz w/HT to Intel Core 2 Duo E6400 2.1
GHz, and it gave me a huge benefit in calculations i was doing.
 as for normal usage, i don't think i can notice a difference..



Re: Quad/Dual Core Duo Questions

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You expected faster processing with a slower clock?

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At the POST screen, it should mention your CPU.  Check what it states
for speed.  Could be you don't have the BIOS setup correctly for
multiplier.

While the OS might make some use of the CPU, and it will probably be
handy with virtual machine programs where you can assign a CPU to a
particular VM, your applications won't get much boost.  Don't know why
you went slower for the CPU clock.  Multiple cores do not make up for
clock rate.


Re: Quad/Dual Core Duo Questions

 ??>> ... 3.2 GHz Pentium with HT (< this is important later), ...
 ??>> ... 2.33 GHz Dual Core Pentium ...

 V> You expected faster processing with a slower clock?

there is also such parameter as Instructions Per Cycle. and pentium4 is
known for very low IPC because of insanely long pipeline.
it works on full speed only when doing some boring loop (such as
cryptography or some kinds of processing).
for most workloads it's pipeline stalls due to branch mispredictions etc.
i'd say Pentium4 3 GHz compares to 1.3-1.4 OtherCPU (AMD ones, Intel Core..)
on typical workloads, and it can be even worse on some workloads..

i've got huge 4x boost for calculations i was doing when moved from 3 GHz
Pentium4 to 2.1 GHz Core2 Duo.



Re: Quad/Dual Core Duo Questions

There never was a 2.33GHz dual-core Pentium D (Pentium 4 Family) the
slowest Pentium D was 2.8GHz if memory serves me correctly.

There is also no 2.33GHz family Pentium-Dual Core E2xxx, the fastest
is the 2.0GHz Pentium Dual-core E2200.

So the CPU in question is most likely a E6540 or E6550, both with 4MB
L@ cache and on the 1333MHz FSB - this chip, with good DDR2-667 or 800
RAM and a modern SATA hard drive should perform over 2-3 times better
than a Pentium 4 3.2GHz, even in single-threaded apps.

Likely causes of molasses effect? Hard drive issue (test speeds?)
speedstep issue (stuck at low speed?) or maybe overheating - is the
cooler correctly installed? Maybe the CPU is thermal throttling. I
doubt Vista would be the issue, as it performs flawlessly even on an
old Pentium 4 or Pentium D at 3GHz.

Re: Quad/Dual Core Duo Questions

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I have tested a P4 3.2 and a Core 2 e6400 2.13GHz in the same PC.
Performance is about the same. Obviously multi-threaded apps are a different
story, but I don't use any. Neither do most users of multiple core machines!



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