Hyper-Threading Technology . Presented By Nagarajender Rao Katoori. Introduction. To Enhance Performance- Increase in clock rate Involves reducing clock cycle time Can increase the performance by increasing number of instructions finishing per second
Nagarajender Rao Katoori
To Enhance Performance-
Increase in clock rate
Involves reducing clock cycle time
Can increase the performance by increasing number of instructions finishing per second
H/w limitations limit this feature
Having frequently used data on the processor caches reduces average accesses time
Processor with out Hyper-Threading Technology
Processor with Hyper-Threading Technology
Ref: Intel Technology Journal, Volume 06 Issue 01, February 14, 2002
Following resources are duplicated to support Hyper-Threading Technology
Figure: Intel Xeon processor pipeline Hyper-Threading Technology
Sharing of Resources Hyper-Threading Technology
ØMajor Sharing Schemes are-
o Full Sharing
Ø Each logical processor uses half the resources
Ø Simple and low in complexity
Ø Ensures fairness and progress
Ø Good for major pipeline queues
ensures progress for both logical processors.
Threshold Hyper-Threading Technology
Ø Puts a threshold on number of resource entries a logical processor can use.
Ø Limits maximum resource usage
Ø For small structures where resource utilization in burst and time of utilization is short, uniform and predictable
Ø Eg- Processor Scheduler
Full Sharing Hyper-Threading Technology
Ø Most flexible mechanism for resource sharing, do not limit the maximum uses for resource usage for a logical processor
Ø Good for large structures in which working set sizes are variable and there is no fear of starvation
Ø Eg: All Processor caches are shared
o Some applications benefit from a shared cache because they share code and data, minimizing redundant data in the caches
Netburst Microarchitecture’s execution pipeline Hyper-Threading Technology
SINGLE-TASK AND MULTI-TASK MODES Hyper-Threading Technology
Business Benefits of Hyper-Threading Hyper-Threading Technology
Web server benchmark performance
Intel’s Hyper-Threading Technology brings the concept of simultaneous multi-threading to the Intel Architecture.
It will become increasingly important going forward as it adds a new technique for obtaining additional performance for lower transistor and power costs.
The goal was to implement the technology at minimum cost while ensuring forward progress on logical processors, even if the other is stalled, and to deliver full performance even when there is only one active logical processor.
Thank you OLTP workload