Skip all navigation and jump to content Jump to site navigation Jump to section navigation.
NASA Logo - Goddard Space Flight Center + Visit NASA.gov
NASA Center for Computational Sciences
NCCS HOME USER SERVICES SYSTEMS DOCUMENTATION NEWS GET MORE HELP

 

User Services
OVERVIEW
ACCOUNT INFO
FAQ
FAQ
Tele Con
GLOSSARY
TUTORIALS
CLASSES & WORKSHOPS

Questions and Answers (06/06/2006)


Q1:
How many people in the audience do not have access to a wireless enabled laptop that could be used during training classes?

Answer:
Approximately one quarter of the audience responded that they did not have access to a wireless enabled laptop. Therefore, the NCCS and SIVO will make plans for alternative access methods to the systems during the training classes.

Q2:
What will the queue structure on the new system look like?

Answer:
In general, the queue structure will be very similar to the queue structure currently in place on the SGI Altix system, Explore.

Q3:
Do you anticipate any issues with regard to the conversion of binary files from halem to the new cluster?

Answer:
systems are little endian, so no problems are anticipated.

Q4:
What about binary files that had not been converted from the CRAY system?

Answer:
There would be a much larger set of issues regarding this type of conversion, but please contact User Services as soon as possible if you need assistance.

Q5:
What are the limitations with regard to address space in memory?

Answer:
The Intel Extended Memory 64 Technology (EM64T) uses both hardware and software to enable 64-bit computing. Therefore, the EM64T provides support for a 64-bit virtual address space, 64-bit pointers, etc. See the following links for more information:

http://www.intel.com/technology/64bitextensions/
http://www.intel.com/products/processor/xeon/index.htm

The Dempsey processors have 36-bits for physical addressing, which is equal to 64 GB of address space (note that one bit is left for the sign). The extended memory technology is used to address memory beyond the 64 GB physical address limit.

Q6:
What is the anticipated date for training on the TAU profiling tools?

Answer:
This and other training courses are being targeted for mid-summer of 2006.


Q7:
When will a full Fortran 2003 compiler be available?

Answer:
Many of the components are supported in current compiler; however there is no one compiler that covers all. The NAG compiler is perhaps the most Fortran 2003 compliant, but still has many limitations. The NCCS will be comparing the different compilers and presenting a feature comparison on the web site in the near future.


Q8:
There was a sense of disappointment in the Intel compiler on the SGI Altix with regard to OpenMP. Will this be better on the cluster?

Answer:
The Intel compilers for the cluster are identical to the Intel compilers on the SGI Altix. When compiling on the cluster, the compilers will create different executables between the two systems in order to better take advantage of the architectures. Therefore, it is not entirely clear if there will be an improvement for OpenMP support on the cluster. To mitigate this, the NCCS will have multiple compilers installed on the new cluster in hopes that there should be at least one compiler to adequately meet the user's needs.


FirstGov logo + Privacy Policy and Important Notices
+ Sciences and Exploration Directorate
+ CISTO
NASA Curator: Mason Chang,
NCCS User Services Group (301-286-9120)
NASA Official: Phil Webster, High-Performance
Computing Lead, GSFC Code 606.2