Semiconductor & Computer Engineering
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The '''''iso-''''' prefix is used to indicate that a given difference measurement (or estimate) is reported while maintaining one or more other parameter(s) fixed. | The '''''iso-''''' prefix is used to indicate that a given difference measurement (or estimate) is reported while maintaining one or more other parameter(s) fixed. | ||
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| + | == Overview == | ||
| + | The ''iso-'' prefix means 'equal'. The word originated from ''îsos'' in Ancient Greek which had a similar definition. The prefix is used to denote that a certain reported difference measurement or estimate was done while maintaining one or more secondary parameters fixed. In other words, an iso-comparison isolates one parameter from a number of parameters that affect each-other. | ||
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| + | iso-comparisons are important for when different parameters may positively or negatively affect the primary parameter being compared. For example, if a CPU core may deliver improved performance versus a predecessor by utilizing a more advanced [[process node]] or by making use of more advanced circuit design techniques or both. Using an iso-process comparison would demonstrate how much benefits came from the design alone. | ||
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| + | For example, "2nd-generation CPU core delivers 10% reduction in power at iso-performance and iso-process" means that the 2nd-generation CPU is able to achieve a reduction of 10% in its power consumption (under certain workload conditions) over the 1st-generation for identical performance level or capabilities on the same [[process node]]. | ||
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| + | == Comparison types == | ||
| + | * '''iso-performance''' - A comparison that is done at a fixed performance level (e.g., at a fixed [[SPEC CPU2006]]/[[SPEC CPU2017|17]] score). | ||
| + | * '''iso-power''' - A comparison that is done at a fixed power level (e.g., 1W/core) | ||
| + | * '''iso-area''' - A comparison that is done at a fixed physical silicon area | ||
| + | * '''iso-frequency''' - A comparison that is done at a fixed frequency (e.g., at 2 GHz for all devices) | ||
| + | * '''iso-throughput''' - A comparison that is done at a fixed throughput (e.g., same memory or PCIe bandwidth) | ||
| + | {{expand list}} | ||
| + | |||
| + | == See also == | ||
| + | * [[PPA]] | ||
Revision as of 15:24, 30 May 2020
The iso- prefix is used to indicate that a given difference measurement (or estimate) is reported while maintaining one or more other parameter(s) fixed.
Overview
The iso- prefix means 'equal'. The word originated from îsos in Ancient Greek which had a similar definition. The prefix is used to denote that a certain reported difference measurement or estimate was done while maintaining one or more secondary parameters fixed. In other words, an iso-comparison isolates one parameter from a number of parameters that affect each-other.
iso-comparisons are important for when different parameters may positively or negatively affect the primary parameter being compared. For example, if a CPU core may deliver improved performance versus a predecessor by utilizing a more advanced process node or by making use of more advanced circuit design techniques or both. Using an iso-process comparison would demonstrate how much benefits came from the design alone.
For example, "2nd-generation CPU core delivers 10% reduction in power at iso-performance and iso-process" means that the 2nd-generation CPU is able to achieve a reduction of 10% in its power consumption (under certain workload conditions) over the 1st-generation for identical performance level or capabilities on the same process node.
Comparison types
- iso-performance - A comparison that is done at a fixed performance level (e.g., at a fixed SPEC CPU2006/17 score).
- iso-power - A comparison that is done at a fixed power level (e.g., 1W/core)
- iso-area - A comparison that is done at a fixed physical silicon area
- iso-frequency - A comparison that is done at a fixed frequency (e.g., at 2 GHz for all devices)
- iso-throughput - A comparison that is done at a fixed throughput (e.g., same memory or PCIe bandwidth)
This list is incomplete; you can help by expanding it.