Specific form factor requirements of notebooks limit them from having exhaustive cooling solutions. As a result, individual components inside the notebook (such as system memory devices) can heat up to the point of exceeding their operating specifications. To ensure that the memory devices operate within their thermal limits, their case temperature needs to be monitored and memory accesses throttled if any memory devices approach their thermal limits. Current lab data taken on multiple notebooks and from analyzing multiple SO-DIMMs show that 1 GB capacity SO-DIMMs and greater are nearing their maximum specified case temperature when running a realistic workload at an ambient temperature of 35°C. The data were taken from Thin and Light notebook designs: the thermal concern for small form factor designs are of even greater concern due do their limited cooling abilities.

Open-loop throttling mechanisms, including DT in SPD, throttle memory based on a thermal prediction scheme that analyzes memory traffic to estimate the temperature of the DRAM case temperatures. These mechanisms lead to over-guardbanding since they always have to assume worst-case environment conditions, such as the ambient temperature of the room. Also, because these mechanisms are estimating thermal parameters only based on memory traffic, they cannot protect all DRAMs from exceeding their maximum case specifications of 85°C.

TS on DIMM, a closed-loop throttling mechanism, offers several benefits over open-loop throttling methods. The closed-loop methodology of TS on DIMM allows it to reduce the guardband substantially over existing methods, increasing system performance by allowing the system to run unconstrained longer before initiating throttling. TS on DIMM also provides a way to control notebook skin temperatures and provides a safeguard mechanism to help prevent the DRAMs from exceeding their maximum case specification of 85°C.

Currently TS on DIMM is an optional feature for DDR2 SO-DIMMs. Intel is working with memory industry to drive this feature into DDR3.