According to
http://www.sun.com/servers/x64/x4600....jsp#question1 Sun
appears to get around 3500 on SPECfp.

They seem to be using some sort of autoparallelizing trick in Sun's
compiler (which is rather well known for SPECtacular optimizations). I
am definitely impressed and quite surprised...

Of course, this trick may be adopted by other vendors just as easily,
the Sun folks hardly have a monopoly on good compilers (and quite
frankly, I would expect Pathscale's to be far more common).

DK

On 12 Jul 2006 19:45:36 -0700, "David Kanter" <(E-Mail Removed)>
wrote:

>According to
>http://www.sun.com/servers/x64/x4600....jsp#question1 Sun
>appears to get around 3500 on SPECfp.
>
>They seem to be using some sort of autoparallelizing trick in Sun's
>compiler (which is rather well known for SPECtacular optimizations). I
>am definitely impressed and quite surprised...
>
>Of course, this trick may be adopted by other vendors just as easily,
>the Sun folks hardly have a monopoly on good compilers (and quite
>frankly, I would expect Pathscale's to be far more common).
>
>DK

So now the question is, is it the cores, the compiler, the o/s, the
communication between the cores, the memory subsystem, all or some of
the above, or something else altogether or as well?

Makes the Woodcrest question less cut and dried.

Ryan

Ryan Godridge wrote:
> So now the question is, is it the cores, the compiler, the o/s, the
> communication between the cores, the memory subsystem, all or some of
> the above, or something else altogether or as well?
>
> Makes the Woodcrest question less cut and dried.

Two words: "Intel compilers". That's now in contrast to another two
words: "Sun compilers".

Yousuf Khan

Yousuf Khan wrote:
> Ryan Godridge wrote:
> > So now the question is, is it the cores, the compiler, the o/s, the
> > communication between the cores, the memory subsystem, all or some of
> > the above, or something else altogether or as well?
> >
> > Makes the Woodcrest question less cut and dried.
>
> Two words: "Intel compilers". That's now in contrast to another two
> words: "Sun compilers".

It's almost certainly Sun's compilers. Unfortunately, we won't know
until they published detailed results...

DK

On Thu, 13 Jul 2006 12:59:40 -0400, Yousuf Khan <(E-Mail Removed)>
wrote:

>Ryan Godridge wrote:
>> So now the question is, is it the cores, the compiler, the o/s, the
>> communication between the cores, the memory subsystem, all or some of
>> the above, or something else altogether or as well?
>>
>> Makes the Woodcrest question less cut and dried.
>
>Two words: "Intel compilers". That's now in contrast to another two
>words: "Sun compilers".
>
> Yousuf Khan

Pity, I was really looking forward to carrying on the times where it
was easy to make choices - not long ago you could have a big heater or
a fast cpu, but not both. Now it might really be necessary to do some
work finding out which camp suits an application or o/s etc better.

So is Sun's a better compiler or a better Spec targetted compiler do
you reckon?

Ryan

Ryan Godridge wrote:
> So is Sun's a better compiler or a better Spec targetted compiler do
> you reckon?


Hard to say, just as it's hard to say in the case of Intel's compilers
too. Sometimes Intel compilers are known only for the benchmark
proficiency. I think Sun being one of the big boys in this game too is
not above doing the same sort of thing. But then again, you can't get
good benchmarks without also producing good code.

Yousuf Khan

YKhan wrote:
> Ryan Godridge wrote:
> > So is Sun's a better compiler or a better Spec targetted compiler do
> > you reckon?
>
>
> Hard to say, just as it's hard to say in the case of Intel's compilers
> too. Sometimes Intel compilers are known only for the benchmark
> proficiency. I think Sun being one of the big boys in this game too is
> not above doing the same sort of thing. But then again, you can't get
> good benchmarks without also producing good code.

To be perfectly honest, Sun's compiler group is far more aggressive
than Intel's in 'cracking' benchmarks, think about how they cracked
art. However, their compilers are also probably used far more often,
simply because that's the compiler you use for SPARC/Solaris.

A lot of the optimizations really don't help much, and that's doubly
the case in peak SPEC scores. In peak submissions, you can use any
combination of compiler flags for any benchmark, with base scores, you
have to use the same compiler flags for all tests.

While it's unclear how often high levels of compiler optimization are
used, the latter seems much more realistic.

DK

On 13 Jul 2006 11:39:13 -0700, "David Kanter" <(E-Mail Removed)>
wrote:

>
>YKhan wrote:
>> Ryan Godridge wrote:
>> > So is Sun's a better compiler or a better Spec targetted compiler do
>> > you reckon?
>>
>>
>> Hard to say, just as it's hard to say in the case of Intel's compilers
>> too. Sometimes Intel compilers are known only for the benchmark
>> proficiency. I think Sun being one of the big boys in this game too is
>> not above doing the same sort of thing. But then again, you can't get
>> good benchmarks without also producing good code.
>
>To be perfectly honest, Sun's compiler group is far more aggressive
>than Intel's in 'cracking' benchmarks, think about how they cracked
>art. However, their compilers are also probably used far more often,
>simply because that's the compiler you use for SPARC/Solaris.
>
>A lot of the optimizations really don't help much, and that's doubly
>the case in peak SPEC scores. In peak submissions, you can use any
>combination of compiler flags for any benchmark, with base scores, you
>have to use the same compiler flags for all tests.
>
>While it's unclear how often high levels of compiler optimization are
>used, the latter seems much more realistic.
>
>DK

So basically with a good compiler, the Opteron beats Woodcrest?

Ryan

On 12 Jul 2006 19:45:36 -0700, "David Kanter" <(E-Mail Removed)>
wrote:

>According to
>http://www.sun.com/servers/x64/x4600....jsp#question1 Sun
>appears to get around 3500 on SPECfp.
>
>They seem to be using some sort of autoparallelizing trick in Sun's
>compiler (which is rather well known for SPECtacular optimizations). I
>am definitely impressed and quite surprised...
>
>Of course, this trick may be adopted by other vendors just as easily,
>the Sun folks hardly have a monopoly on good compilers (and quite
>frankly, I would expect Pathscale's to be far more common).

I think this is one that we're going to have to hold off on until we
get a bit more details. The results are absolutely shocking, and as
the old saying goes, "If it sounds too good to be true..."

For comparison, the best result Sun has so far is 2518 from a x4200
system using a 2.8GHz single-core Opteron. This is using the same
Solaris 10 and Sun Studio 11 OS and compiler mentioned above. Now
DDR2 should a reasonable amount in SPEC CFP and there are 3.0GHz
Opterons out there, but the result still seem rather unbelievable.

-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca

Ryan Godridge wrote:
> So basically with a good compiler, the Opteron beats Woodcrest?

And vice-versa.

Yousuf Khan