[Beowulf] Intel Quad-Core or AMD Opteron

[mcosta at fc.up.pt]

Citando Vincent Diepeveen <diep at xs4all.nl>:

> Even worse,
>
> Does SSE2 code of intel not by default in th eintel primitives have an 'if
> then else' that at opteron it runs without using SIMD?

We used ACML on Opterons and MKL on Xeons.

> But apart from that, SIMD at oldie K8 is very slow compared to core2,
> though not a factor 2. Barcelona for well optimized code should have an
> IPC in SIMD of up to 40+% faster i guess than core2.
>
> So only 2 questions are when they release and especially at *what* price
> for the 4 socket mainboards.
>
> A 16 core barcelona machine with 4 DDR2 memory controllers might be a very
> mighty system for all kind of applications that need shared memory to
> scale well.
>
> When releasing Barcelona core within a few months from now, AMD has a huge
> lead over intel with respect to 4 core cpu's, as it seems to me.
>
> I feel personally intels choice of CPU design using small tiny L1 caches
> from performance viewpoint is a catastrophic one. If there is just ONE
> competitor for an intel chip that manages to clock a cpu nearly at the
> same clock like intel and with the same number of cores, then intel
> usually gets totally outperformed. Now that intel & AMD produce
> cpu's at the same type of machines their cpu's, it seems to me
> that AMD will in general outperform intel.
>
> Comparing the 2006 core2 with a 2003 release is not a very fair
> compare IMHO.

We just compared what was available at the time, there's nothing more  
we could do. I do think that AMD's architecture scales better, and  
that eventually, as the number of cores and sockets increases, Intel  
will switch to integrated memory controllers and some form of cpu to  
cpu bus.

> We can definitely conclude that intel managed to produce their new
> generation cpu ( core2) more than 1 year sooner than AMD did do, using a
> simple trick, namely glueing 2 dual core chips together.

That's right, and in that interval they managed to get ahead, for some  
applications at least.

There is already a "true" quad-core in their roadmap, isn't there?

>
> In the meantime i keep wondering more and more about intel not having an
> equivalent on the market for AMD's hypertransport.

Yep. I do agree with everything you say, I just think that the  
comparison between Xeon's and Opteron's for high performance computing  
is getting harder, since before the em64t I would (and did) choose  
Opterons.

Miguel

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