Software defined memory (SDM) has evolved in the past decade from DRAM accessible over custom fabrics to DRAM accessible over standard fabrics (SDM-F) and now memory over storage (SDM-S). This presentation will include a comparison of SDM-F and SDM-S, the advantages of each, key drivers of behavior and performance, and fit to specific use cases.

1. COMPARING SOFTWARE DEFINED MEMORY OPTIONS
BENZI GALILI
CHIEF OPERATING OFFICER
SCALEMP, INC. See all the presentations from the In-Memory Computing
Summit at http://imcsummit.org

2. SOFTWARE DEFINED MEMORY OPTIONS: OVER FABRIC, OVER
STORAGE

3. SDM-F KEY ATTRIBUTES
 IN PRODUCTION SINCE 2012
 Memory access prediction engine: various miss-prediction techniques (code scanning, analytics)
 Dataset/Working-set detection: keep as much of the data local (advanced caching)
 SIMPLICITY BY DESIGN
 Deploy locally or from network (any PXE-based provisioning: Puppet, Chef, etc…)
 Run any Linux OS or Linux-based Hypervisor
 Support switched and switchless (star) topologies
 Memory nodes can be based on the lowest cost processors
 HIGH PERFORMANCE: bandwidth aggregation up to 512Gb/s
 FREE VERSION AVAILBLE: download from www.scalemp.com

4. SDM-S BUILDS ON SDM-F AND IMPROVES
 PROVEN: leverages years of SDM-F production experience
 IMPROVED: adjust to media characteristics
 Overcome higher latency: convert synchronous memory requests into asynchronous ones
 Deeper prediction for higher media utilization
 RELIABLE: Shapes flash write-access
 Shape write-access patterns (example: batch writes) for increased endurance

5. WHICH SDM IS RIGHT FOR ME?
Workload/Environment Attributes SDM-F SDM-S
Predictability / Randomness Excellent fit Excellent fit
Concurrency / Parallelism No concurrency requirement Requires high-concurrency
Use case: DRAM replacement Alternative to high-density DIMMs Excellent fit
Use case: DRAM expansion Excellent fit Excellent fit
Use case: <3TB memory Not recommended Excellent fit
Use case: maximum memory capacity Up to 2PB Up to 128TB
Cost (media + software) $12~$24 per GB $4~$5 per GB
Deployment requirements Bare-metal + high-end fabric Bare-metal + certified NVM drive

6. THANK YOU!
SDM@SCALEMP.COM