Dual processor laptops?

[blu at vl.com (Tom Metro)]

Mark J. Dulcey wrote:
> There are two ways to make a dual-core CPU. One way is to put two 
> complete processors on one IC die, as the Core Duo 2 and the TurionX2 
> do.
> (I'm not sure which method is used by the original Core Duo.)

The Core Duo seems so close to the Core 2 Duo in performance and 
behavior, that I'd guess it uses the same architecture (just 
incrementally improved).


> The fastest available CPU right now is the Core Duo 2. The earlier Core 
> Duo isn't quite as fast on a matched-clock basis (maybe 20% slower)...

According to:
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2808&p=6

Core 2 Duo provides a 2% to 15% boost, depending on the benchmark.


> AMD's competition is the TurionX2; it's about even with the Core Duo...

I haven't seen (or looked for) benchmarks comparing the two mobile 
processors, but there is a fairly dramatic difference between X2 and 
Core 2 Duo on the desktop.


Below is what I posted to the BBLISA list on this same thread.

  -Tom


Larry Beaulieu wrote:
> Also note that right now you'll see 2 different dual-core product
> lines. "Core Duo" processors started shipping earlier this year, 
> "Core 2 Duo" is the later iteration and offers an incremental
> performance improvement...

When shopping for a dual-core laptop earlier this Fall, I used this article:

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2808

as one reference, which says essentially the same thing - that the newer
Core 2 Duo provides a small, incremental improvement.

According to the article Core 2 Duo should be available in laptops now
(the article is from early August, and thus a bit dated), and selling
for the same price, so it would be the preferred option, though I
haven't noticed it in any of the laptops advertised to consumers. If
you're willing to use the non-2 version, you'll have more model choices,
and will probably get a better price.

The article also mentions AMD's Turion 64 X2 and notes its limited
availability. That doesn't seem to still be the case. I've seen lots of
models with X2s lately. However, I believe the benchmarks still give the
edge to Intel's dual-core CPUs (on performance; I don't know about power
consumption).


Nicholas Kathmann wrote:
> Last I heard, the dual-cores offer a 1.4x - 1.8x performance upgrade
> over a single processor.  You don't get full 2x...

At a recent BLU talk by Alex Vasilevsky, Founder of Virtual Iron (they
make "Enterprise-Class Virtualization" software (Xen based)), gave
similar numbers. I think he said 1.5x. Probably depends on the benchmark
or application.


Scott Ehrlich wrote:
> How does this really differ, if at all, from having two separate
> processors on the motherboard?

Is two sockets even a practical option on a laptop? I've never heard of
such a thing. If so, it'd be a very high-priced specialty model.

anandtech.com and most of the other hardware sites have background
articles on dual-core technology.


> Ignore budgets for now.

Dual-core shouldn't have a big impact on budgets. It's quickly becoming
the mainstream, pushing single core models to the value market.

I've seen laptops with Intel dual-core CPUs selling in the $500s and the
Toshiba I purchased was $700. Buy a Dell through normal corporate buying
channels with support contracts, and of course you'll pay more, but the
premium for dual-core shouldn't be too bad.

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/

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