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les robertson cernit0999 1

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LCB Workshop, Marseilles, 1 October 1999. Team members: Ingo Augustin, Jean-Philippe ... Holographic storage. development stalled waiting. for a new material ... – PowerPoint PPT presentation

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Title: les robertson cernit0999 1

1
Technology Trackingprocessors, memory, storage,
architecures

Summary of conclusions
LCB Workshop, Marseilles, 1 October 1999
Team members Ingo Augustin, Jean-Philippe
Baud, Fabien Collin, Charles Curran,
Fabrizio Gagliardi, Frédéric Hemmer,Sverre
Jarp, Gordon Lee, Alessandro Marchioro,
Bernd Panzer Steindel, Les Robertson, Ben
Segal, Rainer Többicke, Pierre Vande Vyvre

2
processors, memories, basic systems

Previous report (1996) was
pessimistic about frequency
optimistic about parallelism (instructions/cycle)
about right for performance and cost
The Semiconductor Industry Association 1997
roadmap predicts a new generation every 2 years
with 0.1? at 2 GHz appearing around LHC startup
Previous forecasts have been too
conservativeBUT we start to come close to
fundamental limits like the thickness of the gate
oxide and power dissipationfor which novel
solutions are required

3
Semiconductor Industry Association (SIA) 1997
technology forecast
Solution being pursued No known solution
4
Processor Cost Caveats

Estimated cost in 2005
0.75-1.60 per CERN-Unit
CAUTION!
Investments, costs and prices
fabulous fab costs
production volume?
competition?
Achieved parallelism
the best processors only reach 1.8 ipc on integer
codes
will Merced make a significant advance?
compilers may be as important as semiconductors
Home office PCs are the driving force

5
Secondary Storage
75 of hard disks go into PCs

hard disk market is big healthy
30B with 5-6 large manufacturers
areal density should continue to evolve at 60
per year
from 4 Gbits/inch2 to about 60 Gbits/inch2 in
2005
20-25 Gbits/inch2 demonstrated
and prices should continue to decrease at 35
per year
2-4/GB in 2005
Technology limits - room for optimism
super-paramagnetic limit currently around 30-40
Gbits/inch2
competitive RD in materials and heads
alternative technologies using advanced
magneto-optics
Data rate per unit of installed capacity - could
be a concern
data rate increases only with the linear density
if the mass market does not demand significantly
smaller disks we shall have to purchase more
capacity than we really need

6
Optics Exotics

Paradoxically
now that magnetic recording has caught up with
optical recording densities (5 Gbits/inch2 with
a red laser)
the entertainment business has produced a product
which could play an important role in low end
computer storage
DVD-RAM - 9.4GB in 2000
access time, data transfer rate - no match for
hard disk
but may well displace magnetic tape in the home
office
Holographic storage
development stalled waitingfor a new material
active consortium (military interest)
Nothing else beyond the stage of technology
demonstration

STOP PRESS The Keele Ultra High Density
Memory 2.3 TB on a credit card for 50
7
Tertiary Storage

Major doubts about the long term
the market driver is backup and archive --
write once, read never
the commodity market will have strong
competition from DVD-- low-end tape devices may
disappear
BUT - several recent/announced products for the
data centre (half inch, linear)
STK 9840, DLT 8000, LTO
with strong roadmaps for the next 5-6 years
2005 20-50 MB/sec gt100GB per cartridge
Costs
reliable drives unlikely to go below 10-20K
robotics - gt20 per slot (no improvement on
todays best price)

1998 Estimated tape revenue by device class
0.5"19 mm Helical
5B market
6
0.25" Linear
9
8 mm Helical
12
0.5" Linear
50
4 mm Helical
23
8
Tape media costs

At LHC media costs will dominate
cannot assume that there will be successors to
current product families in the next 5 years
so we may only see factor of 4 improvement in
recording density over todays half inch linear
giving about 0.50 per GB for raw tape
Worst case scenario?
If hard disk is 2/GB and DVD-RAM 0.20many
applications will abandon tape for the higher
functionality of random access storage
Big problem for the magnetic tape business - and
HEP
We should be very careful about planning for tape
as a medium for active data storage

9
Storage Management Systems

Lack of standardisation gt no exchange of data
Limited high end market
missing functionality
product plans / survival unclear
Relatively straightforward HEP requirements
good scalability, predictable performance
Could be a case where a HEP solution would be
better and affordable (but surely not multiple
HEP solutions!)
Storage Area Networks, Global Shared File Systems
very interesting developments
could mature by 2005, and should be followed
but watch the impact on storage costs

10
Architecture, Interconnects Clusters

Exotic architectures and technologies will have
no impact on general purpose computing in the
next 5 years
quantum, optical .. multi-threaded (TERA), chaos,
..
games consoles, integrated TV/Internet
devices will help to squeeze prices, push
performance of regular PCs
Expect the distinction between large SMPs, NUMA
shared memory and SPP systems to become less
clear
BUT large integrated systems are likely to remain
relatively expensive and be unnecessary for HEP
Should see healthy developments in scalable
clusters with standardised high performance
commodity interconnects
management tools a concern
there are many promising development projects,
but they may emphasise high availability/performan
ce rather than high throughput

11
Summary
full report http//nicewww.cern.ch/les/pasta/wel
come.html

processors OK
disks OK - but watch the I/O-rate/capacity ratio
Concern about the future of magnetic tapes
it would be wise to consider using disk for
active data
relegating tape to archive and data exchange
The inherent HEP parallelism makes it realistic
to build large computing fabrics from inexpensive
components
But the management - farms and storage - may
require HEP developments
Maybe open source may allow this to be done as
part of a wider collaboration