'True' vs. 'Pseudo' Quad Core

There is a serious amount of discussion in the software developer trade rags
about programming for multi-core systems. Intel, of course, is leading the way
by making multi-core software development tools available, most notably C
compilers and supporting stuff.

Bottom line is that today, October 11, 2008, an application that makes true use
of mulitple cores and threads is probably very rare. However, that does not
invalidate the multi-core approach to provide more computing power with a
smaller electrical power budget. After all, Windows, Linux, and BSD Unix (for
the Mac OS X crowd) all run multiple threads and concurrent applications which
can be dispatched to idle or low use CPUs.

What I have not seen in all the multi-core discussion are the effects of memory
bus and memory bandwidth on making effective use of all them cores. Way back
when I worked with Honeywell's monster multicore mastodon mainframes, CPU
utilization percentages dropped off with each added processor. Honeywell had a
standard quad processor offering, and GE San Jose asked for and got special 5-
and 6-processor systems for their nuclear power plant computations. Of course,
back then in the '70's, a CPU took up an entire cabinet the size of a commercial
refrigerator (which is how they looked). Possibly circuit paths a couple of
inches long have reduced contention for memory access by multi-core CPUs. I
would still like to see someone's heavily instrumented analysis, but I suspect
that Intel keeps that info closely under wraps. Same with AMD... Ben Myers

On Fri, 10 Oct 2008 23:02:09 -0500, "S.Lewis" <> wrote:

<SNIP>
>
>As you're configuring the system, just get the most capable CPU you can get
>within your sense of value. You'll notice the price premium differences
>when putting the system together.
>
>It's not as if there is a huge wealth of applications coded to fully utilize
>multi-core processors (someone please correct me if I'm wrong, but I don't
>think so).
>
>Additionally, I know of no (mainstream) software written to take advantage
>of hyperthreading.
>
>So, no. You're not being silly imo.
>
>
>Stew
>

So far the only applications I have come across that 'recommend' quad
core is video editing software, and then only for editing hi-definition
video. There is probably other software that can take advantage of four
cores but my sense is that there's not a lot of it. Not now, at least.

So for now, it seems to me, unless someone knows they would benefit from
quad core, the main reason for buying a quad from Dell is if it's part
of a package deal at an attractive price (what Stew was referring to,
and me with my bang-for-the-buck-o-meter.)

Daddy

RnR wrote:
> On Sat, 11 Oct 2008 11:44:55 -0400, Ben Myers
> <> wrote:
>
>> Bottom line is that today, October 11, 2008, an application that makes true use
>> of mulitple cores and threads is probably very rare.
>
> Yep, I read the same thing months ago so I don't recommend quad cores
> to most. The performance boost isn't worth it from what I read but
> some people just want to believe and it's their money so who am I
> to tell them how to spend their money unless they ask me.

Daddy wrote:
> So far the only applications I have come across that 'recommend' quad
> core is video editing software, and then only for editing hi-definition
> video. There is probably other software that can take advantage of four
> cores but my sense is that there's not a lot of it. Not now, at least.
>
> So for now, it seems to me, unless someone knows they would benefit from
> quad core, the main reason for buying a quad from Dell is if it's part
> of a package deal at an attractive price (what Stew was referring to,
> and me with my bang-for-the-buck-o-meter.)
>
> Daddy
>
> RnR wrote:
>> On Sat, 11 Oct 2008 11:44:55 -0400, Ben Myers
>> <> wrote:
>>
>>> Bottom line is that today, October 11, 2008, an application that
>>> makes true use
>>> of mulitple cores and threads is probably very rare.
>>
>> Yep, I read the same thing months ago so I don't recommend quad cores
>> to most. The performance boost isn't worth it from what I read but
>> some people just want to believe and it's their money so who am I
>> to tell them how to spend their money unless they ask me.


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.

On Sat, 11 Oct 2008 14:34:07 -0400, Bill Ghrist
<> wrote:

>Daddy wrote:
>> So far the only applications I have come across that 'recommend' quad
>> core is video editing software, and then only for editing hi-definition
>> video. There is probably other software that can take advantage of four
>> cores but my sense is that there's not a lot of it. Not now, at least.
>>
>> So for now, it seems to me, unless someone knows they would benefit from
>> quad core, the main reason for buying a quad from Dell is if it's part
>> of a package deal at an attractive price (what Stew was referring to,
>> and me with my bang-for-the-buck-o-meter.)
>>
>> Daddy
>>
>> RnR wrote:
>>> On Sat, 11 Oct 2008 11:44:55 -0400, Ben Myers
>>> <> wrote:
>>>
>>>> Bottom line is that today, October 11, 2008, an application that
>>>> makes true use
>>>> of mulitple cores and threads is probably very rare.
>>>
>>> Yep, I read the same thing months ago so I don't recommend quad cores
>>> to most. The performance boost isn't worth it from what I read but
>>> some people just want to believe and it's their money so who am I
>>> to tell them how to spend their money unless they ask me.
>
>
>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?

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).

On Oct 10, 8:18 am, Daddy <da...@invalid.invalid> 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
news:48f14e98$0$4893$...
> 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
> news:48f14e98$0$4893$...
>> 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