SJ – Sept 2004 1

Future processors:

What is on the horizon for HEP

computingSverre Jarp

CERN openlab CTO IT Department, CERN

SJ – Sept 2004 2

Items to consider

Processors will offer: 64-bit pointers (and long ints) Little growth from pure GHz “Multi-core” designs

as a compensation More and more heat !

Systems will offer: Heterogeneity ? Growth through

Brain, not Brawn Various form factors Units of one Mega-SPECint-2000

SJ – Sept 2004 3

Processor consideratio

ns

SJ – Sept 2004 4

64-bit computing

Are your codes 64-bit clean?

If not, convert NOW !!

All -processor families are now 64-bit capable

AMD Athlon-64/Opteron (AMD64) IBM Power family (also MAC G5) Intel Itanium Intel Prescott/Nocona (EM64T) SUN Sparc

SJ – Sept 2004 5

Single processors

In the past there were rapid uni-processor speed increases

Between 2000 and 2003 we saw spectacular growth rates: ACGR: ~40%

Slow growth since then Global SPECint number can be helped by

other factors, however. Bigger caches, faster buses, improved

compilers have helped produce 40-50% increase over the last two years: ACGR ~20%

90 nm is not helping raw clock speed much

Same issue for all three: AMD, IBM, Intel

SJ – Sept 2004 6

Multi-core designs

Moore’s original law said: We are “Cramming more components onto

Integrated Circuits” Article published in 1965 (Almost 40 years ago)

The good news: We still are! Transistor count still grows

Best way to put them to use Multiple processors on a die: 1 2 4 …

Great news for HEP’s “trivial paralellism”

But, systems will become more complex

A dual-socket 4-way CMP server may require 8-16 jobs in flight !!

SJ – Sept 2004 7

Heat issue Big surprise to the whole industry?

Processors are getting hot Many mainstream processors are in the range 90 – 135

W Fortunately, some processor designs have

focused on low power These may serve as design examples for hotter

cousins (in the future)

Nevertheless, the problem will not go away

Are we prepared to bring water cooling back?

SJ – Sept 2004 8

System consideratio

ns

SJ – Sept 2004 9

Heterogeneity Unavoidably, our grids will

have to cater with heterogeneous architectures

Mainstream Linux/GNU support may become the common denominator 32-bit only x86 processors 64-bit capable x86 processors Itanium processors IBM Power5 systems

All have Red Hat/Suse server support

SJ – Sept 2004 10

Brain, not brawn

Increasingly important to extract performance from whole system -architecture CMP designs (as discussed) Cache hierarchy and bus designs Operating system scalability Compiler cleverness Middleware optimization Application optimization

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SJ – Sept 2004 11

System form factors

Our beloved DP (read: Dual Socket) systems may go out of fashion, in favour of: 1) Single-socket (still multi-processor)

systems 2) Racks full of game systems ?

HEP needs to understand the implications of new efforts, such as the nVIDIA graphics or the Sony/Toshiba/IBM cell processor

3) Larger servers For instance: 4 sockets with 4 processors each

4) Blade-based racks Fully integrated with disks, network I/O, etc.

This is an entire “research topic” in itself

SJ – Sept 2004 12

“Megaracks” Expect companies in the future

to offer “units” of 1 Mega-SPECint-2000 For instance:

2000 SPECint/core 6 cores/socket 4 sockets/2U 22 2U/rack

Maybe our computer centres only need to house a few “hot” racks??

SJ – Sept 2004 13

Conclusion LEP experienced 3 distinct

“system” cycles Mainframes RISC systems Linux

PCs

Be prepared for deep changes Also during the LHC era

SJ – Sept 2004 14

Backup

SJ – Sept 2004 15

Are you ready for a

64-bit world ?

SJ – Sept 2004 16

Mega SPECint racks ?

SJ – Sept 2004 17

Water cooling ?

?