Memory eXpansion Technologies - overview
This project is focusing on the development of memory controllers for PC Servers which incorporate IBM's MXT technology. A memory controller for use with Intel's Pentium III processor has been developed and is being demonstrated. This memory controller, Pinnacle, was developed jointly with ServerWorks, Inc., and is now available in the merchant chip market from them. Looking forward, we are working to incorporate this technology as a standard feature in all future open system servers, through joint development and licensing of the industry.
MXT technology also requires enhancements to the virtual memory managers of the operating systems which support the technology. We have companion efforts to develop these enhancements for all the popular operating systems. The Linux effort is highlighted at http://oss.software.ibm.com/developerworks/opensource/mxt.
Press Release
- IBM First to Deliver Memory Breakthrough in Servers, February 11, 2002.
- New IBM Chip Doubles Computer Memory, June, 2000.
Special Issue on Memory Compression

Is Memory eXpansion Technology for you?
The benefits you realize with MXT will vary depending on the actual operating system, application, and load environment of your system. It is therefore difficult to make general statements about the amount of memory that you can expect to save if you transition to an MXT-enabled server. IBM Research has developed a tool to help you make informed decisions about the benefits of MXT. We call this the MXTTool, and it can be run on your Windows or Linux server with the results conveniently displayed on any Java-capable client machine. You don't need a graphical interface on the machine you monitor. You don't need to even be near the server you want to monitor. Just install the MXT Monitor daemon service on the server to be monitored and see the results on any Java-capable machine anywhere else on the internet.
- Before downloading this software, please read and understand the licensing agreement presented on the download page.
- Download an executable tool that will measure the compressibility of memory on a Windows NT 4.0, Windows 2000, or Red Hat Linux* machine plus a Java GUI to display compressibility results
* Windows NT 4.0, Windows 2000, and Red Hat Linux 7.x are currently the only supported environments for the monitor daemon. If you have other requirements, the software for one of these environments may work with little or no modification.
Interactive Demonstration of Parallel Compression
Parallel compression using a Cooperative Dictionary by J. Robinson.
Publications
IBM Memory Expansion Technology (MXT), R. B. Tremaine, P. A. Franaszek, J. T. Robinson, C. O. Schulz, T. B. Smith, M. Wazlowski and P. M. Bland, IBM Journal of Research and Development, vol. 45, No. 2, pp. 271-285, March 2001.
Memory Expansion Technology (MXT): Competitive Impact, T. B. Smith, B. Abali, D. E. Poff, R. B. Tremaine, IBM Journal of Research and Development, vol. 45, No. 2, pp. 303-308, March 2001.
Memory Expansion Technology (MXT): Software Support and Performance, B. Abali, H. Franke, D. E. Poff, R. A. Saccone, Jr., L. M. Herger, and T. B. Smith, IBM Journal of Research and Development, vol. 45, No. 2, pp. 287-301, March 2001.
Algorithms and data structures for compressed-memory machines, P. A. Franaszek, P. Heidelberger, D. E. Poff, J. T. Robinson, IBM Journal of Research and Development, vol. 45, No. 2, pp. 245-258, March 2001.
On internal organization in compressed random-access memories, P. A. Franaszek, J. T. Robinson, IBM Journal of Research and Development, vol. 45, No. 2, pp. 259-270, March 2001.
"Pinnacle: IBM MXT in a memory controller chip", R. B. Tremaine, T. B. Smith, M. Wazlowski, D. Har, K. Mak, and S. Arramreddy, IEEE Micro, pp. 56-68, March/April 2001.
"Cache-memory interfaces in compressed memory systems", C. Benveniste, P. Franaszek, and J. Robinson, to appear in IEEE Transactions on Computers, 50, 11, November 2001.
"Hardware Compressed Main Memory: Operating System Support and Performance ", B. Abali, M. Banikazemi, X. W. Shen, H. Franke, D. E. Poff, and T. B. Smith, to appear in IEEE Transactions on Computers, 50, 11, November 2001.
"Performance of Hardware Compressed Main Memory", B. Abali, H. Franke, X. Shen, D. E. Poff, T. B. Smith, Proceedings of the 7th Annual International Symposium on High-Performance Computer Architecture, Jan. 2001, pp. 73-81.
"Reliability - Availability - Serviceability of a Compressed Memory System", C. L. Chen, D. Har, K. Mak, C. Schulz, B. Tremaine, and M. Wazlowski, Proceedings of the International Symposium on Dependable Systems and Networks, pp. 163-168, IEEE, 2000.
"On management of free space in compressed memory systems", P. Franaszek, P. Heidelberger, and M. Wazlowski, Proceedings of International Conference on Measurement and Modeling of Computer Systems, pp. 113-121, ACM, 1999.
"Parallel compression with cooperative dictionary construction", P. Franaszek, J. Robinson, and Thomas, Proceedings of 1996 Data Compression Conference DCC'96, pp. 200-209, IEEE 1996.
Patents
Compression store addressing, P. Franaszek, US Patent No. 6,240,419, 2001.
System and Method of compression and decompression using store addressing, P. Franaszek, US Patent No. 5,864,859, 1999.
Parallel compression and decompression using a cooperative dictionary, P. Franaszek, J. Robinson, and J. Thomas, US Patent No. 5,729,228, 1998.
System and Method for Reducing Memory Fragmentation by Assigning Remainders to Share Memory Blocks on a Best Fit Basis, P. Franaszek, US Patent No. 5,761,536, 1998.
Technical Reports available through IBM's CyberDigest
Performance of hardware compressed main memory . B. Abali, H. Franke, D. Poff, T.B. Smith. Report RC 21799, IBM Watson Research Center, Yorktown Heights, NY 2000.
Algorithms and data structures for compressed memory machines. P. Franaszek, P. Heidelberger, D. Poff, J. Robinson. Report RC 21833, IBM Watson Research Center, Yorktown Heights, NY 2000.
Cache-memory interfaces in compressed memory systems. C. Benveniste, P. Franaszek, J. Robinson. Report RC 21662, IBM Watson Research Center, Yorktown Heights, NY 2000.
Design and analysis of internal organizations for compressed random access memories. P. Franaszek, J. Robinson. Report RC 21146, IBM Watson Research Center, Yorktown Heights, NY 1998.