'True' vs. 'Pseudo' Quad Core

On Oct 10, 8:18 am, Daddy wrote:
Trying to decide between dual core and quad core for my next Dell desktop.

From what I understand, Intel's current quad-core processors (at least,
the ones offered by Dell) are not truly quad core, but more like two
dual-core processors glued together. There are four cores there, no
doubt, but certain components are shared between the two halves.
Obviously, I'm missing a lot of information.

What really is the difference, if anything, between the current
generation of Intel quad core processors and a 'true' quad core? This
may be a huge question, so I'd be fine with links to more detailed
explanations.

Are today's Intel quad-cores a legitimate choice, or are they a
'gimmick', like hyperthreading, something to satisfy the market's demand
while they work on the 'real deal'?

Thanks for your help.

Daddy

Given that QuadCore isn't (really) more expensive (at least by the
bang-for-the-buck meter , I would certainly go for 4 cores. I did,
in fact. (And when I bought it, the config with Q6600 was even
$50 cheaper than the one with a tad bit faster Core2Duo.)

Either way it is going to be screaming fast, I agree. On the other
hand, for any realistic computer use, I think one can expect that
4 cores come to tell. And major software can either already use
them effectively, or will be able to very shortly.

"Tony Harding" wrote in message
...
Daddy wrote:
Trying to decide between dual core and quad core for my next Dell
desktop.

From what I understand, Intel's current quad-core processors (at least,
the ones offered by Dell) are not truly quad core, but more like two
dual-core processors glued together. There are four cores there, no
doubt, but certain components are shared between the two halves.
Obviously, I'm missing a lot of information.

What really is the difference, if anything, between the current
generation of Intel quad core processors and a 'true' quad core? This may
be a huge question, so I'd be fine with links to more detailed
explanations.

Are today's Intel quad-cores a legitimate choice, or are they a
'gimmick', like hyperthreading, something to satisfy the market's demand
while they work on the 'real deal'?

I upgraded my XPS720 from a Core2 processor, E6600, to a quad, Q6600, and
saw an enormous real world increase in performance when editing &
rendering video. Other stuff is instantaneous no matter which CPU.

FWIW, I don't consider hyperthreading a gimmick - it's a way of wringing
some extra performance from a single core processor and works the way
Intel describes (had one on my Dim8400).


Tony,

If you have any links or stuff to show/demonstrate how hyper-threading
contributes to better system performance, I'd appreciate having that
information.

My understanding was/is that it was only a benefit for any software(s) that
were coded to utilize the feature.

I still haven't been able to locate any mainstream apps that do that. I'm
sure there are coders out there who've tailored stuff for programming and
whatnot, I've just not seen/read of any great pay off for HT.

Thanks,

Stew

S.Lewis wrote:
"Tony Harding" wrote in message
...
Daddy wrote:
Trying to decide between dual core and quad core for my next Dell
desktop.

From what I understand, Intel's current quad-core processors (at least,
the ones offered by Dell) are not truly quad core, but more like two
dual-core processors glued together. There are four cores there, no
doubt, but certain components are shared between the two halves.
Obviously, I'm missing a lot of information.

What really is the difference, if anything, between the current
generation of Intel quad core processors and a 'true' quad core? This may
be a huge question, so I'd be fine with links to more detailed
explanations.

Are today's Intel quad-cores a legitimate choice, or are they a
'gimmick', like hyperthreading, something to satisfy the market's demand
while they work on the 'real deal'?
I upgraded my XPS720 from a Core2 processor, E6600, to a quad, Q6600, and
saw an enormous real world increase in performance when editing &
rendering video. Other stuff is instantaneous no matter which CPU.

FWIW, I don't consider hyperthreading a gimmick - it's a way of wringing
some extra performance from a single core processor and works the way
Intel describes (had one on my Dim8400).


Tony,

If you have any links or stuff to show/demonstrate how hyper-threading
contributes to better system performance, I'd appreciate having that
information.

My understanding was/is that it was only a benefit for any software(s) that
were coded to utilize the feature.

I still haven't been able to locate any mainstream apps that do that. I'm
sure there are coders out there who've tailored stuff for programming and
whatnot, I've just not seen/read of any great pay off for HT.

No links, I'm remembering what I can from my Dim8400 days. The question
of software written for a specific architecture is a perennial issue,
but AFAIK HT worked as described. Whether software was developed for it
is another matter entirely, e.g., budget vs actual.

Scott Davis wrote:
On Sat, 11 Oct 2008 14:34:07 -0400, Bill Ghrist
wrote:


I got a Precision T3400 recently with the Q6600. I was originally
looking at a dual core, but the Dell "deal" on the configuration with
the quad core was so much better that I couldn't pass it up. One of the
things that surprised me: I brought up Task Manager while I was running
an AVG virus scan and saw that all four cores were nearly maxed out
(with no applications other than AVG and Task Manager running). After
the fact I found that Grisoft does document that AVG will use multi-core
processing as available, but I was impressed--especially since this is
free software.

Did it make a noticeable difference?

Hard to tell. This is switching from a five year old Dimension 4550
with a P4 cpu and 512M RAM to a Precision T3400 with a Q6600 and 2G RAM,
SATA 3Gb/s hard drive, etc. It seems infinitely faster, but how much of
that is the quad core, I don't know. I would have to think that
scanning with four processors instead of one must be faster, given that
it looks like the AVG scan is processor bound rather than disk bound
(based upon the high processor usage shown in Task Manager). One thing
is nice is to be able to start up Firefox, Thunderbird, and OpenOffice
all at once as soon as I boot up. Some of that I suspect is due to the
quad core. Even if most applications are not yet able to use the
multiple cores, you still get the advantage of having multiple
applications running in different cores.

* S.Lewis:

[HT]

My understanding was/is that it was only a benefit for any software(s) that
were coded to utilize the feature.

It's not necessary to "code" for HT, it's enough if the software is
multithreaded. HT brings a performance increase if the threads are
utilizing different parts of the CPU, if all threads do the same HT
doesn't help.

I still haven't been able to locate any mainstream apps that do that. I'm
sure there are coders out there who've tailored stuff for programming and
whatnot, I've just not seen/read of any great pay off for HT.

For example, most better video codecs are mutithreaded and benefit a lot
from HT.

BTW: the fact that multithreading (which is what HT is) is used not only
in Itanium but also in Suns UltraSPARC T-series should show that it's
more than just a gimmick. HT also helps with intels ATOM, if you switch
off HT you just slow down your Netbook ;-)

Benjamin

Daddy wrote:
Trying to decide between dual core and quad core for my next Dell desktop.

From what I understand, Intel's current quad-core processors (at least,
the ones offered by Dell) are not truly quad core, but more like two
dual-core processors glued together. There are four cores there, no
doubt, but certain components are shared between the two halves.
Obviously, I'm missing a lot of information.

What really is the difference, if anything, between the current
generation of Intel quad core processors and a 'true' quad core? This
may be a huge question, so I'd be fine with links to more detailed
explanations.

Are today's Intel quad-cores a legitimate choice, or are they a
'gimmick', like hyperthreading, something to satisfy the market's demand
while they work on the 'real deal'?

Thanks for your help.

Daddy

yes, current quad cores are quite quad, more like 2 dual cores
however, it's not a huge hit on speed really, it's worth buying em
they are not 'fake' or anything

"Benjamin Gawert" wrote in message
...

snip

Benjamin -

Thanks for an explanation that attempts to describe some tangible benefit of
HT.

For the record, I've always enabled HT on machines that have the capability
'just in case' there is/was some less than obvious benefit.

My skepticism resides with Intel and not with the posters here though I
consider myself 'an Intel guy'.


Stew

I seem to recall that hyperthreading caused slower performance for
certain applications. Am I remembering this correctly?

Daddy

S.Lewis wrote:
"Benjamin Gawert" wrote in message
...

snip

Benjamin -

Thanks for an explanation that attempts to describe some tangible benefit of
HT.

For the record, I've always enabled HT on machines that have the capability
'just in case' there is/was some less than obvious benefit.

My skepticism resides with Intel and not with the posters here though I
consider myself 'an Intel guy'.


Stew

* Daddy:
I seem to recall that hyperthreading caused slower performance for
certain applications. Am I remembering this correctly?

Yes. For single threaded apps where only one app is running HT causes a
very slight performance decrease due to the overhead and how it
distributes CPU ressources. But this was hardly noticeable with the
first HT CPUs (P4 XEON 1.7GHz), and is probably even less noticeable
today, especially since more and more apps are to at least some degree
multithreaded.

Benjamin