1 / 21

SuperRange: Wide Operational Range Power Delivery Design for both STV and NTV Computing

SuperRange: Wide Operational Range Power Delivery Design for both STV and NTV Computing. Xin He, Guihai Yan, Yinhe Han, Xiaowei Li Institute of Computing Technology, Chinese Academy of Sciences. The need of wide operation range.

vui
Download Presentation

SuperRange: Wide Operational Range Power Delivery Design for both STV and NTV Computing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SuperRange: Wide Operational Range Power Delivery Design for both STV and NTV Computing Xin He, Guihai Yan, Yinhe Han, Xiaowei Li Institute of Computing Technology, Chinese Academy of Sciences

  2. The need of wide operation range • Microprocessor’s supply voltage range has been gradually increasing in these year • Intel Pentium Processor has a supply voltage range from 0.9V to 1.5V to support DVFS • Intel Sandy Bridge Processor requires a higher than nominal voltage to boost performance Turbo DVFS Intel PentiumProcessor Turbo Boost in Intel Sandy Bridge 0.9V 1.5V (66.7%)

  3. The need of wide operation range • Near Threshold Computing: set supply voltage to a value near to transistor’s threshold voltage (0.4V-0.6V) Turbo DVFS Intel ISSCC2012 NTC 0.28V-1.2V Future Microprocessor has wide supply voltage range. Brings challenges to power delivery design

  4. Background of Power Delivery Design • Voltage regulator is key to deliver power at a specified voltage level • Linear regulator-LDO • Switching regulator • Buck regulator(Off-VR) • Switch capacitor regulator(On-VR) Buck Regulator Switch Capacitor Regulator

  5. Power Conversion Efficiency Characteristics • VRs are delivering power to wide operational range cores High PCE High PCE • Off-VR: • High switching loss • On-VR: • Narrow optimal region • LDO-VR: • Limited efficiency Low PCE Low PCE Conventional design can’t meet the need of wide voltage range

  6. Contribution • Explore the design space of wide operational range power delivery design • Propose SuperRange, a wide operation range power delivery scheme • Present a VR aware power management algorithm to maximize performance under given power budget

  7. Design space exploration • Explore three optional design • Off-VRs • Two Off-VR evenly located • Off-VR + LDO-VR • An Off-VR serves as an frontend • Off-VR + On-VR • Off-VR delivers to STV and On-VR to NTV

  8. Option 1：Off-VRs scheme • Loss in Off-VRs dominants! 20% Cross 10%

  9. Option 2：LDO-VR scheme • In LDO-VR • PCE is limited by the ratio of output voltage to input voltage • PCE is lower than 30% when delivering to NTV region

  10. Option 3：Off-VR + On-VR scheme • Using Off-VR to deliver to STV region • Two step voltage conversion • How to decide intermediate voltage 1) Fixed intermediate voltage • Off-VR delivers fixed output voltage 2V • Tuning On-VR paramsto achieve further conversion • PCE of Off-VRs is high • On-VR couldn’t deliver to all NTV levels at high PCE

  11. Off-VR + On-VR scheme 2) Using varied intermediate voltage • Off-VR delivers to varied voltage levels • Duty cycle tuning • On-VR further step these intermediate values to 0.4V-0.6V • Pros: • On-VR has high PCE(around 80%) • Cons: • The PCE of Off-VR remains low because of small load current

  12. Proposed SuperRange Design • Multi-phase Off-VR provides an opportunity to improve load current, thus PCE get improved • Modern Off-VR can dynamically change number of working phases • Decreasing the number of working phases would increase output ripple • 1.5uH inductor is big enough to reduce the ripple with acceptable area overhead

  13. SuperRange Overview • Supporting STV • Voltage conversion to STV is performed by Off-VR • Supporting NTV • Two step conversion. • Off-VR sets to single working phase • On-VR achieves further conversion(e.g. 3:1)

  14. VR aware power management algorithm • Maximize performance under given power budget • Find optimal core counts and VF setting More cores, Low voltage Few cores, High voltage • PCE with varying load current • Although low voltage improve app power efficiency, it degrades the PCE

  15. Algorithm • Determine voltage setting candidates • Computes the total powers when all cores are active at each voltage level • Selects the lowest voltage () and the highest voltage () • Determine active core count • Calculate max active core count at voltage and get corresponding performance • Compare the performance with and make decisions

  16. Experimental Setup • Target processor characteristics • Multicore processor consists 16 ALPHA cores which has 9 power state • (1.2v, 1.9GHz), (1.1v, 1.7GHz), (1.0v, 1.5GHz)… (0.4v, 0.3GHz) • 32MB LLC, distribute directory-based MESI • On chip interconnection: mesh + router • Voltage regulator model • Single topology (3 to 1) Switch capacitor voltage regulator • Buck voltage regulator like TI TPS 54912

  17. Power Conversion Efficiency SuperRange combines the advantages of Off-VR and On-VR and exhibits high PCE over the entire voltage range

  18. Comparison • Performance comparison in power-constrait system • SuperRange outperforms LDO scheme by 50% and • Off-VR scheme by 30%

  19. Comparison • Maximum achievable performance comparison under shrinking power budget • On average, SuperRange achieve 52% and 170% higher PCE • than Off-VR and LDO-VR scheme.

  20. Conclusion • Power delivery design for wide operational range is an important issue • Explore the optional power delivery design scheme • The proposed SuperRange scheme achieves high PCE over the entire operational range • Propose a VR aware power management algorithm

  21. Thank You for Your Attention • Question?

More Related