1. Embedded SCI Solutions
SCI Reflective Memory
(Experimental)
Atle Vesterkjær
Dolphin Interconnect Solutions AS
Olaf Helsets vei 6, N-0621 Oslo, Norway
Phone: (47) Fax: (47)
Mail:

2. Dolphin Interconnect Solutions AS
Introduction
This presentation aims to give you an idea of how SCI can be used for embedded / realtime solutions.
SCI Reflective Memory is a software Reflective Memory solution.
SCI Reflective Memory is a library that you can use to build Reflective Memory applications from, without having to consider the low-level implementation of SCI.
This presentation can also be viewed as a follow-up of Dolphins first lecture here in Dublin led by Hugo Kohmann on Monday.
Dolphin Interconnect Solutions AS

3. SCI Reflective Memory Application specific code built in
Reflective Memory shell
SISCI library
SISCI Driver
IRM Driver
Reflective Memory
SCI Reflective Memory is a software reflective memory solution based on Dolphins Adapter cards and software. SCI Reflective Memory is a SISCI programming shell that programmers can use to write application specific code for their Reflective Memory application.
A lot to be said, but it should not be more than an introduction at this point.
Dolphin Interconnect Solutions AS

4. Dolphin Interconnect Solutions AS
Contents
Introduction to Reflective Memory
Dolphins HW and SW used in building SCI Reflective Memory
SCI Reflective Memory technical description, features and benefits
This 1,5 h presentation is fully devoted to SCI Reflective Memory. The presentation will be divided into three different parts. They are: (on screen).
I find it most natural to start with a presentation of RM. There is several reasons to why I want to do this:
RM is a bit on the side of the other subjects that have been presented on SCI summer school, and I find it natural to bring you up to date on this field first so that you better will understand choices conserning tradeoffs when making the content of the black kettle.
This way the presentation will follow the same chain of events as I did when I developed SCI reflective memory.
2. Hugo said a lot about this on Monday. I will repeat shortly things that are central in SCI RM.
3. And three: This is the real thing. I guess this point is obvious.
Dolphin Interconnect Solutions AS

5. SCI Reflective Memory Lab 1600-1730
Test and evaluation of SCI Reflective Memory demo programs.
The exercises are found in your labmanual (one sheet).
You will also be asked some questions of how to make an application specific program from the Reflective Memory shell, and to comment on the performance of specific tasks. For the Lab you will be given a lab manual and left to yourselves, but Hugo and me will of course be available for questions, problems and interesting discussions.
Dolphin Interconnect Solutions AS

6. Reflective Memory Application specific code built in
Reflective Memory shell
SISCI library
SISCI Driver
IRM Driver
Reflective Memory
So lets take this one step at a time and start with investigating the Reflective Memory Technology.
Dolphin Interconnect Solutions AS

7. Dolphin Interconnect Solutions AS
Reflective Memory
Reflective Memory systems are a solution to problems raised by message passing in multicomputer environments.
Reflective Memory systems belong to the class of disributed shared memory systems (DSM)
Reflective Memory (RM) systems (In computer literature also referred to as mirror memory systems or replicated memory systems)
DSM means that the shared memory space is distributed to several nodes.
Dolphin Interconnect Solutions AS

8. Dolphin Interconnect Solutions AS
Reflective Memory
Each system processor includes a dual-ported local physical memory.
A part of memory is configured as logically shared.
The Reflective Memory is composed of all these physically distributed, logically shared memory parts mapped into a global (shared) address space: The Reflective Memory Space.
Private memory
module
Private memory
module
Reflective Memory
Reflective Memory
This is organized in a way that each system processor includes a dual-ported local physical memory, a part of which is configured as logically shared. The RM is composed of all these physically distributed, logically shared memory parts mapped into a global (shared) address space. The Reflective Memory Space.
The main idea of RM is that if a shared data item might be reused, an accurate copy of it should be kept in each processors local memory. Upon each write to a shared memory location, the network interface automatically updates all system copies. Shared memory read operations are performed on local memory. The reflective memory copies on all nodes should be equal, at least updated be for each local access. Apart from this Reflective memory is just memory. Read and write to memory.
Private memory
module
Reflective Memory
Dolphin Interconnect Solutions AS

9. Dolphin Interconnect Solutions AS
Reflective Memory
The main idea of Reflective Memory is that if a shared data item might be reused, an accurate copy of it should be kept in each processors local memory.
Private memory
module
Private memory
module
Reflective Memory
Reflective Memory
Upon each write to a shared memory location, the network interface automatically updates all system copies. Shared memory read operations are performed on local memory. The reflective memory copies on all nodes should be equal, at least updated be for each local access. Apart from this Reflective memory is just memory. Read and write to memory.
Private memory
module
Reflective Memory
Dolphin Interconnect Solutions AS

10. Dolphin Interconnect Solutions AS
Reflective Memory
Read operations are performed on local memory
Write operations generates automatic updates of all system copies by a broadcast transaction
Private memory
module
Private memory
module
Reflective Memory
Reflective Memory
This is organized in a way that each system processor includes a dual-ported local physical memory, a part of which is configured as logically shared. The RM is composed of all these physically distributed, logically shared memory parts mapped into a global (shared) address space. The Reflective Memory Space.
The main idea of RM is that if a shared data item might be reused, an accurate copy of it should be kept in each processors local memory. Upon each write to a shared memory location, the network interface automatically updates all system copies. Shared memory read operations are performed on local memory. The reflective memory copies on all nodes should be equal, at least updated be for each local access. Apart from this Reflective memory is just memory. Read and write to memory.
Private memory
module
Reflective Memory
Dolphin Interconnect Solutions AS

11. Dolphin Interconnect Solutions AS
Advantages and disadvantages of Reflective Memory systems compared to other DSM systems:
Advantages:
Computation typically overlaps with communication
Memory access time is usually constant and thus deterministic.
Because of their inherent replication thay are good for fault tolerance
Simpler, and have been commercially implemented for decades.
Read operations are fast.
Disadvantages:
For applications characterized with longer sequences of writes to the same segments, RM systems may produce unneccessary traffic.
The interconnection medium usually represent a bottleneck due to many data transfers.
Processes that write to the same shared memory location must be explicitly synchronized.
I have been a bit selective when presenting advantages and disadvantages of reflective memory systems compared to DSM systems. Some argue that the interconnection medium for RM systems must support one to all broadcast communication, in which I disagree since I mean that multicast could be just as good if performance and fault tolerance is ensured.
This also applies to the argument concerning removing/reducing layered protocol SW and OS overhead, datareflection being concurrernt(ok), passive (not) and automatic (not). We provide a solution that is better on performance and fault tolerance anyway, and still easy to implement.
Dolphin Interconnect Solutions AS

12. Reflective Memory applications
Aircraft, Ship and Submarine Simulators
Automated Testing Systems
Industrial Automation
High-Speed Data Acquisition
Applications could be any system that uses DSM, or in other words needs concurrent activity, as for SCI. It is though particulary suited for failover systems. Because of their inherent replication thay are good for fault tolerance.
Dolphin Interconnect Solutions AS

13. Reflective Memory features
Reflective Memory updates can occur on any type of interconnect.
Reflective Memory systems can use any type of topology.
Reflective Memory systems are not limited by any particular memory consistency model.
The shared memory regions can be mapped either dynamically or statically.
Apart from the important rule that states that each node should have an accurate copy of the reflective memory space in local memory, reflective memory is just any other shared memory. Read it and write to it, but make sure that only one node has access to a shared memory loaction at a time.
Dolphin Interconnect Solutions AS

14. Typical Reflective Memory features
Automatic updates of remote shared memory copies
Data filtering: Maybe not every temporarily stored variable have to be reflected?
Reflective Memory consistency: The shared region can only be accessed by one party at the time.
Only shared writes are propagated through the system
Should be able to comment widely on these. Look at spesification.
Dolphin Interconnect Solutions AS

15. Typical Reflective Memory features
one-to-all broadcast communication (hardware based)
computation overlaps with communication
Hardware support for heterogeneous computing could significantly improve system usability.
explicitly synchronization (hardware based): Hardware support for synchronization increase performance.
Dolphin Interconnect Solutions AS

16. Why SCI Reflective Memory?
Reflective Memory is a DSM architecture, like SCI, only organized in another way.
Reflected Memory could easily be implemented in Dolphin’s HW and SW.
SCI systems have good fault tolerance and redundancy characteristics.
Competitive performance ratio for Dolphin’s SCI products (Will get back to this later).
This sums up the reflective memory part of the presentation next up is a description of the Dolphn Hardware and SW used in SCI Reflective memory, but let us first ask look at the question: Why SCI Reflective Memory.
First of all it is doable and a new interesting market where we want introduce SCI. Secondly we belive that we can make good products. This is based on the fact that we have experience with Interconnect solutions, confidence in SCI’s guaranteed delivery and strength in performance (throughput and latency). It could also be implemented with already commercial hardware modules.
Dolphin Interconnect Solutions AS

17. SCI Reflective Memory
Application specific code built in
Reflective Memory shell
SISCI library
SISCI Driver
IRM Driver
Reflective Memory
SCI Reflective Memory is a software reflective memory solution based on Dolphins Adapter cards and software.
SCI Reflective Memory is a SISCI programming shell that programmers can use to write application specific code for their Reflective Memory application.
Therfore the best way to explain SCI RM is to start with Dolphins HW and SW.
For know let us just accept these statements and look at the other engredieens:
Dolphin HW and SW used for building SCI Reflective Memory->Skriv bedre.
Dolphin Interconnect Solutions AS

18. PMC/PCI SCI-64 Adapter Card
Adapter Cards
D307 - SBus
D310 - PCI32
D314 - PMC32
D320 - PCI64
D323 - PMC64
D330 - PCI 66
Switches
D way (SBus)
D way (PCI)
D way (PCI)
D way switch
SCI Reflective Memory is a SISCI based SCI solution and can be used with all dolphin products that supports SISCI.
Dolphins Adapter Cards were thoroughly described on Monday. I will only repeat a little bit of that for now, and tell you that RM will support all of them if needed. Currently we are running on PMC/PCI64, also by using D515. Should also tell something about what these cards do.
The picture shows the D320 card and D515 switch.
Ha med Hugo Kohmans notat.
The SCI PCI-64 Card is the high-performance, economical way to build
System Area Networks for clustering of personal computers, workstations
and servers. Dolphin Interconnect Solution makes full effort of the IEEE
Scalable Coherent Interface standard’s leading data link rates
and the highly available PCI bus for connection to memory, processor and I/
O modules. A PCI SCI system is ideal for highly available, scalable database
systems and other mission-critical enterprise servers.
Further information can be found at
Dolphin Interconnect Solutions AS

19. Programming Interface:
Application (i.e C-style)
SISCI API
SISCI driver
IRM driver
Application
(Performance tool)
SISCI library
SISCI Driver
IRM Driver
Hardware abstraction
layer (PAL)
Figure from Hugos notes on Monday. This is what I see.
The “Software Infrastructure for SCI (SISCI)” is an Application
Programming Interface (API) for SCI. Dolphin Interconnect Solutions
provides a well documented SISCI API library and example programs for
interconnection of several nodes in various multiprocessor topologies. A
SISCI API application operates on the Dolphin Interconnect Resource
Manager (IRM). The programming interface is in ANSI C.
PCI-SCI
adapter card
Dolphin Interconnect Solutions AS

20. Dolphin Interconnect Solutions AS
SISCI features
Access to High Performance HW
Highly Portable
Cross Platform / Cross Operating system interoperable
Simplified SCI Programming
Flexible
Reliable Data transfers
Hostbridge / Adapter Optimization in libraries
Described on Monday.
Dolphin Interconnect Solutions AS

21. SCI Reflective Memory Application specific code built in
Reflective Memory shell
SISCI library
SISCI Driver
IRM Driver
Reflective Memory
Finally!
Dolphin Interconnect Solutions AS

22. SCI Reflective Memory: General
GENIF
SISCI
IRM
DLPI/
NDIS
TCP/UDP IP
Kernel Space
User Space
SISCI API
Socket API
The first demo of SCI Reflective Memory is implemented for a two node reflective memory configuration.
The implementation is done in User Space.
The figure on the top left is from Hugo Kohmans lecture on Monday used to describe the SW arch. The development of SCI RM is in User Space as a first approach.
The SCI Reflective Memory is implemented for a two node reflective memory configuration, there is no special reason that it should not work for more nodes as well, but I will get back to that.
The implementation os done in userspace, as instead of other options kernel space and HW.
Hardware implementation
Reflective memory
Software implementation
User Space
Kernel Space
Dolphin Interconnect Solutions AS

23. SCI Reflective Memory: Overview
SCI Reflective Memory Library
SCI Reflective Memory Features
Reflective Memory Example programs
Performance
The current version of SCI Reflective Memory contains a library, examples and demo programs. I also to refer to this library as RM shell, for reasons I will get back to.
Dolphin Interconnect Solutions AS

24. SCI Reflective Memory Library: Overview
Idea
Structure
Memory Management
Synchronization
Applications
Applications = How to build applications. Each of them needs a detailed description
Dolphin Interconnect Solutions AS

25. SCI Reflective Memory Library: Idea
A library to build applications from in order to provide a flexible interface to our cards.
SISCI functions
Relation to other SISCI C-programs
Synchronization
After going through the same steps as we have done in this lecture, in addition to studying other vendors and academic institutions work on RM I came up with this.
Talk of an application specific demo not available yet. This is because there are many specific conserns that will be described later. (We would very much like partners that are interested in a joint venture)
2. The SISCI functions is used for remote access.
3. The structure of the SCI Reflective Memory Software is made very much alike the other SISCI programs so that it will be easy for the application specifc programmer to use. User friendly and known.
4. Synchronization is needed, since only one node is allowed to write to the shared (reflective) memory at the time.
Dolphin Interconnect Solutions AS

26. SCI Reflective Memory Library: Structure
Memory management
Application specific code should be used for processing, and the SISCI functions for memory access
Synchronization
In order to guarantee that the local shared reflective memory copies are kept up to date only one node is granted write-access at the time.
Read operations can occur at any time.
See userguide chapter 3.1
Comment on the last mark: Read operations can occur at any time. This is not a rule, but a general feature that can be changed by the application specific programmer.
Dolphin Interconnect Solutions AS

27. SCI Reflective Memory Library: Memory Management
Segments, duplex mapping.
Memory read and write operations
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

28. SCI Reflective Memory Library: Segments, duplex mapping
Local segment(Node1)
Remote segment map (Node1)
Local segment (Node2)
Remote segment map (Node2)
The node preparing to transfer data has to connect to a segment on the node receiving data. In order to get the two nodes to write to each other, they both have to create (at least) one local segment, and they both have to open up a connection to the remote segment (which is created as local on the other node)
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

29. SCI Reflective Memory Library: Segments, duplex mapping
Local segment (Node1)
Local segment (Node2)
Remote segment map (Node1)
Remote segment map (Node2)
For all RM copies to be uniform, there is a need for an additional mapping as shown above.
This mapping is carried out by by writing to both the localSegment- and remoteSegment mapping during each write operation. The operations are the same on both nodes.
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

30. SCI Reflective Memory Library: Segments, duplex mapping
Node1:
local-map:
Create, prepare, map (local), set available
remote-map:
Connect, map (remote)
For each write operation to local memory, a write operation to the remote memory is automatically carried out by software.
Node2:
local-map:
Create, prepare, map (local), set available
remote-map:
Connect, map (remote)
For each write operation to local memory, a write operation to the remote memory is automatically carried out by software.
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

31. SCI Reflective Memory Library: Segments, duplex mapping
If data is written to the Reflective Memory, it is first written into local memory, then transferred to remote memory by any of the SISCI data transfer functions. The programmer is responsible for obeying the strict ordering rule: All write operations to the local memory shall be reflected to the remote memory immediately.
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

32. SCI Reflective Memory Library: Memory read and write operations
Remote access by SISCI functions
SCIMemCopy
SCITransferBlock
SISCI DMA Engine
*remotePtr = value;
Local access by
*localPtr=value;
memcpy(localBuffer, dummyBuffer, size);
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

33. SCI Reflective Memory Library: Data transfer
A private memory buffer is copied into the Reflective Memory Space
All three steps are mandatory
Remote Segment
SRC Buffer
Local Segment
Private
Local RM
Remote RM
Size
offset
A lot to do here. Can add several foils.
Dolphin Interconnect Solutions AS

34. SCI Reflective Memory Library: Synchronization
A central point in a RM system is RM consistency. RM read operations can be performed on local memory, but it should not be possible to have modified data another place in the system. A method that ensures consistent RM copies when nodes are competing for the shared resources is needed. Practically this means that a local access should not be possible when a remote access is in progress, and only one node should have write access to the shared data at the time.
Dolphin Interconnect Solutions AS

35. SCI Reflective Memory Library: Synchronization
Reflective Memory consistency
Polling - asynchronous
Interrupts – timesliced
Polling is used for better flexibility
In SISCI there are two options that can be used for synchronization, polling and interrupts. Interrupts could be used in a timesliced manner, but for asynchronous handshaking without blocking program execution polling is needed. Thus the only way to swap between computation and communication is to use polling for synchronization.
To avoid deadlock.
Dolphin Interconnect Solutions AS

36. SCI Reflective Memory: How to build Reflective Memory applications
Memory access is taken care of by the reflective memory transfer functions
Synchronization is used to protect the shared data from corruption
Dolphin Interconnect Solutions AS

37. SCI Reflective Memory: Features
The SCI Reflective Memory is for a two node reflective memory configuration.
If more nodes shall be supported a modified synchronization sheme has to be implemented. Apart from that there is no other limits in making a multinode SCI Reflective Memory
Dolphin Interconnect Solutions AS

38. SCI Reflective Memory: General features
All nodes share the RM space.
All nodes have a local copy of the entire RM space.
The local copies on the subsequent nodes are automatically updated.
The synchronization logic ensures that only one node has write access to the RM at the time, keeping all RM copies consistent.
RM write operations are multicasted to all nodes in the system.
Dolphin Interconnect Solutions AS

39. SCI Reflective Memory: General features
computation overlaps with communication: Using DMA transfers for update of remote RM copies enables computation to overlap with communication, when specific flags are set.
One-to-all multicast communication is used for remote RM updates.
Shared data regions are organized as segments
Dolphin Interconnect Solutions AS

40. SCI Reflective Memory: General features
Push-only: Only shared write operations are propagated through the system. A write to the local RM is distributed (reflected) to the RM on all nodes. RM read operations are performed on the local RM copy.
DMA-, block-, memcopy- and shared memory transfers are supportedby the SISCI API and the SCI Reflective Memory. When building an application the desired transfer mechanism can be selected.
Dolphin Interconnect Solutions AS

41. SCI Reflective Memory: Supported OS
In general this is just like for the rest of the SISCI package, but since SCI Reflective Memory is under development we have not been able to port to all operating systems (OS) yet.
Currently supported OS are:
Windows (NT & 2000, x86)
Linux (2.2)
Solaris (2.6 / 7, SPARC)
Next in line of OS that are being ported to:
Lynx
VxWorks (POWERPC)
NB Read Release notes
Dolphin Interconnect Solutions AS

42. SCI Reflective Memory example programs
General Reflective Memory
Special Reflective Memory
Multimap Reflective Memory
Must say something about why these programs were made.
Dolphin Interconnect Solutions AS

43. General Reflective Memory
Only one SISCI segment is created on each node
The segments are linked together in RM style.
Local Segment
Node 1
Local Segment
Node 2
See userguide 3.3. The easiest implementation of an RM solution based on the previous 37 overheads.
Dolphin Interconnect Solutions AS

44. Special Reflective Memory
Bot nodes have read access to the whole Reflective Memory Space segment, but write access to different halves of the Reflective Memroy Space.
Not really a Reflective Memory solution, but an example of how it can be manipulated for specific applications
Local Segment
Node 1
Local Segment
Node 2
See userguide 3.3. Not really an RM program, but an optimalization where possible application specific concerns have been made.
- Write access node 1
- Write access node 2
Dolphin Interconnect Solutions AS

45. Multimap Reflective Memory
Local Segment 1
Node 1
Local Segment 2
Local Segment 3
Local Segment N
Local Segment 1
Node 2
Local Segment 2
Local Segment 3
Local Segment N
Instead of putting the whole RM space in one segment, the user of rm_multimap controls several segments.
Thus the only time nodes are competing for a resource is when the same segment is requested by more than one (both nodes) at the same time.
See userguide 3.3 In many ways an optimalization of RM general
Dolphin Interconnect Solutions AS

46. How to run the example programs
In the start-up face of each program you will be asked to enter:
Adapter number
Remote Nodeid
SegmentSize
(Number of segments)
help
The next slide a list of central commands that are present in all example programs printed during program execution
Dolphin Interconnect Solutions AS

47. How to run the example programs
These are the available commands: rm-read: Read from Reflected Memory. rm-write: Write data to the Reflected Memory. Special RM write functions: rm-dma: DMA transfers between two nodes. rm-block: Block transfers between two nodes. rm-shmem: Shared memory transfers between two nodes. rm-memcopy: Transfer data to a previously mapped remote area.
The next slide a list of central commands that are present in all example programs printed during program execution
Dolphin Interconnect Solutions AS

48. How to run the example programs
Special RM test functions: bench-dma: DMA transfers between two nodes. RM style. bench-block: Block transfers between two nodes.RM style. bench-shmem: Shared memory transfers between two nodes.RM style. bench-memcopy: Transfer data to a previously mapped remote area. bench-full: Test of all RM write-transfers between two nodes. Special RM test functions where only the remote copy is written to: single-dma: DMA transfers between two nodes. single-block: Block transfers between two nodes single-shmem: Shared memory transfers between two nodes. single-memcopy: Transfer data to a previously mapped remote area. single-full: Test of all RM write-transfers between two nodes.
The next slide a list of central commands that are present in all example programs printed during program execution
Dolphin Interconnect Solutions AS

49. How to run the example programs
test-dma: DMA transfers between two nodes, no sync. test-block: Block transfers between two nodes, no sync. test-shmem: Shared memory transfers between two nodes, no sync. test-memcopy:Transfer data to a previously mapped remote area, no sync. test-full: Test of all NON-RM write-transfers between two nodes. file: Print performance parameters to file performance: Print performance parameters for this node parameters: Print key parameters for this node loops: Number of write-commands in the test routines costart: Test with traffic from both nodes starting concurrently costop: Disable concurrent start signal help: This helpscreen q: quit
The next slide a list of central commands that are present in all example programs printed during program execution
Dolphin Interconnect Solutions AS

50. Dolphin Interconnect Solutions AS
Performance
The measurements have been made under the operating system (OS) Windows 2000, but performance is not OS dependent.
Dolphin Interconnect Solutions AS

51. Dolphin Interconnect Solutions AS
SISCI Performance
Highly dependent of the PC Chipsets
Latency 2.2 microseconds
Throughput Application to Application using SISCI
85 MB/s (33Mhz/32 Bit PCI)
120 MB/s (33 Mhz/64 Bit PCI)
240 MB/s* (66 Mhz/64 Bit PCI)
As Hugo said. The beauty is for future implementations where RM performance will follow SISCI performance. ->details?
Dolphin Interconnect Solutions AS

52. Dolphin Interconnect Solutions AS
Performance
The characteristics of the test machines were:
DELL PowerEdge 6300
Pentium II Xeon
CPU clock 400 MHz
256 MB RAM
512 KB Level 2 Cache Memory
440 NX PCI Chipset
Four system processors
Dolphin Interconnect Solutions AS

53. Performance (one-way)
The throughput of remote write operations
The throughput of a loop containing RM synchronization and remote write operations.
The throughput of a loop containing RM synchronization, local write operations and remote write operations. RM-style
One way
Dolphin Interconnect Solutions AS

54. Performance (one-way)
RM SCIMemCopy transfers without writing to the local segment:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

55. Dolphin Interconnect Solutions AS
Performance
RM SCIMemCopy transfers:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

56. Dolphin Interconnect Solutions AS
Performance
NON-RM SCIMemCopy transfers:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

57. Performance (Transfer in both directions simultanously)
The throughput of remote write operations
The throughput of a loop containing RM synchronization and remote write operations.
The throughput of a loop containing RM synchronization, local write operations and remote write operations. RM-style
One way
Dolphin Interconnect Solutions AS

58. Dolphin Interconnect Solutions AS
Performance
RM SCIMemCopy transfers without writing to the local segment:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

59. Dolphin Interconnect Solutions AS
Performance
RM SCIMemCopy transfers:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

60. Dolphin Interconnect Solutions AS
Performance
NON-RM SCIMemCopy transfers:
Segment size: Latency: Throughput:
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
us MB/s
Dolphin Interconnect Solutions AS

61. Dolphin Interconnect Solutions AS
Future Plans
We are working in finding partners that are interested in joining us in developing an application based on SCI Reflective Memory for them.
PSB66 release
Dig deeper into kernel space and/or hardware to optimize performance and ease of use
There are three areas where improvments can be done:
First we need to make an application specic demo, in which we are looking for partners with knowledge of RM to tell us what they want and need. Maybe a failover application would be the natural next step.
Secondly we are waitng for the release of PSB66, which will lead to better performance rates.
And third. It could be possible to implement a solution in kernel spece and hardware for even better optimzation and availability.
Dolphin Interconnect Solutions AS

62. Dolphin Interconnect Solutions AS
Key statement
The industy leading throughput, and latency of Dolphins interconnect solutions will soon be available for the Reflective Memory market.
Dolphin Interconnect Solutions AS

63. Dolphin Interconnect Solutions AS
Important terms
We hope that you now will understand the meaning of the terms:
Reflective Memory
PMC/PCI Adapter Cards
SISCI
SCI Reflective Memory transfer functions
SCI Reflective Memory synchronization
SCI Reflective Memory duplex mapping of segments
Dolphin Interconnect Solutions AS

64. Dolphin Interconnect Solutions AS
Questions?
Dolphin Interconnect Solutions AS

65. Thank you for listening to this presentation
Thank you for listening to this presentation! See you in the Lab in half an hour!
SCI Reflective Memory
Atle Vesterkjær
Dolphin Interconnect Solutions AS
Olaf Helsets vei 6, N-0621 Oslo, Norway
Phone: (47) Fax: (47)
Mail:
Dolphin Interconnect Solutions AS