Thermal regulation for solid state memory
View Patent ↗A chassis for a storage system contains a digital chamber that houses conventional electronic components and a thermal chamber that houses non-volatile solid state memory such as flash memory. A temperature regulating system monitors temperature within the digital chamber to keep the components therein below their maximum junction temperature. The temperature regulating system tightly regulates the temperature of solid state memory chips to within a nominal operating temperature range selected to extend the lifetime and/or improve the endurance and reliability of the solid state memory. The temperature regulating system may regulate different memory chips to different nominal temperatures based on the operations being performed and lifetime factors for the memory chips including current health and prior use.
1. A storage system housed within a chassis, the storage system comprising:
a thermal chamber configured within the chassis and comprising:
a plurality of solid state storage devices configured to store data and provide access to stored data;
a plurality of temperature sensors thermally coupled to the plurality of solid state storage devices; and
a cooling system configured to remove heat from the thermal chamber;
a heating system comprising a plurality of heating elements, wherein one of the plurality of heating elements is configured to add heat locally to a subset of the plurality of solid state storage devices; and
a temperature regulating system configured to cause the cooling system to remove heat from the thermal chamber and simultaneously cause the one of the plurality of heating elements to add heat locally to the subset of the plurality of solid state storage devices to maintain each of the solid state storage devices within a fixed range of temperature in a presence of a temperature gradient within the thermal chamber due to a location of the cooling system, based on an operating condition and a projected lifetime of a solid state storage device in the operating condition sensitive to temperatures outside a fixed range.
2. The system of claim 1 , wherein the plurality of temperature sensors are thermally coupled to different ones of the plurality of solid state storage devices.
3. The system of claim 1 , wherein a set of temperature sensors in the plurality of temperature sensors are thermally coupled to a given solid state storage device, the solid state storage device comprising a plurality of memory chips.
4. The system of claim 3 , wherein a target temperature sensor in the set of temperature sensors on the solid state storage device is thermally coupled to a set of proximate memory chips in the plurality of memory chips, the target temperature sensor providing thermal readings corresponding to the set of memory chips to the temperature regulating system.
5. The system of claim 1 , wherein a set of heating elements in the plurality of heating elements are thermally coupled to a given solid state storage device, the solid state storage device comprising a plurality of memory chips.
6. The system of claim 5 , wherein a target heating element in the set of heating elements on the solid state storage device is thermally coupled to a set of proximate memory chips in the plurality of memory chips, the target heating element configured to heat the set of memory chips.
7. The system of claim 6 , wherein the target heating element substantially heats the set of memory chips compared to other memory chips on the solid state storage device.
8. The system of claim 1 , wherein one or more of the heating elements comprises a resistive heating device for adding heat proportional to received current.
9. The system of claim 1 , wherein the cooling system comprises a plurality of fans for generating air flow over the plurality of solid state storage devices to remove heat.
10. The system of claim 1 , wherein operation condition of a solid state storage device comprises one or more of substantially performing memory read operations, substantially performing memory write operations, substantially remaining idle, a total number of storage device.
11. The storage system of claim 1 , wherein the temperature regulating system is configured to cause the one of the plurality of heating elements to add a first amount of heat and another one of the plurality of heating elements to add a second amount of heat to maintain each of the solid state storage devices within the fixed range of temperature.
12. The storage system of claim 1 , wherein the plurality of solid state storage devices is disposed on at least one memory blade.
13. The storage system of claim 12 , wherein the plurality of solid state storage devices is disposed on a plurality of memory blades arranged as an array in the thermal chamber.
14. The storage system of claim 13 , wherein the temperature regulating system is configured to cause the cooling system to remove more heat from a middle of the array than an edge of the array.
15. The storage system of claim 1 , wherein the cooling system comprises a plurality of cooling elements, and wherein the temperature regulating system is configured to estimate a lifetime of a first one of the plurality of cooling elements based on a performance disparity between the first one of the plurality of cooling elements and a second one of the plurality of cooling elements.
16. A method comprising:
receiving, at a temperature regulating system, a temperature reading from a plurality of temperature sensors thermally coupled to a plurality of solid state storage devices in a thermal chamber;
comparing, by the temperature regulating system, the temperature reading with a nominal temperature range of the plurality of solid state storage devices; and
causing, by the temperature regulating system, a cooling system to remove heat from the thermal chamber, and simultaneously causing one of a plurality of heating elements to add heat locally to the plurality of solid state storage devices, thereby maintaining each of the solid state storage devices within a fixed range of temperature in a presence of a temperature gradient within the thermal chamber due to a location of the cooling system, based on an operating condition and a projected lifetime of a solid state storage device in the operating condition sensitive to temperatures outside a fixed range.
17. The method of claim 16 , wherein one or more of the heating elements comprises a resistive heating device for adding heat proportional to received current.
18. The method of claim 16 , further comprising causing the one of the plurality of heating elements to add a first amount of heat and another one of the plurality of heating elements to add a second amount of heat to maintain each of the solid state storage devices within the fixed range of temperature.
19. The method of claim 16 , wherein the plurality of solid state storage devices is disposed on a plurality of memory blades arranged as an array in the thermal chamber, and the method further comprises causing the cooling system to remove more heat from a middle of the array than an edge of the array.
20. The method of claim 16 , wherein the cooling system comprises a plurality of cooling elements, and wherein the method further comprises estimating a lifetime of a first one of the plurality of cooling elements based on a performance disparity between the first one of the plurality of cooling elements and a second one of the plurality of cooling elements.