Dirk
Dirk leads the Novel Computing Technologies group at Heidelberg University. He and his group work mostly on FPGAs, including applications, designing and taping out own FPGA chips (check out the FABulous eFPGA project) and various FPGA tools (like the FPGADefender FPGA bitstream virus scanner). His group designed a single FPGA system with 16 RISC-V threads running at 500 MHz and we just achieved the first 1GHz RISC-V implementation running on an FPGA.
Beitrag
While FPGA developers usually try to minimize the power consumption of their designs, we approached the problem from the opposite perspective: what is the maximum power consumption that can be achieved or wasted on an FPGA? Short answer: we found that it’s easy to implement oscillators running at 6 GHz that can theoretically dissipate around 20 kW on a large cloud FPGA when driving the signal to all the available resources. It is interesting to note that this power density is not very far away from that of the surface of the sun. However, such power load jump is usually not a problem as it will trigger some protection circuitry. This led us to the next question: would a localized hotspot with such power density damage the chip if we remain within the typical power envelope of a cloud FPGA (~100 W)? While we could not “fry” the chip or induce permanent errors (and we tried several variants), we did observe that a few routing wires aged to become up to 70% slower in just a few days of stressing the chip. This basically means that such an FPGA cannot be rented out to cloud users without risking timing violations.
In this talk, we will present how we optimized power wasting, how we measured wire latencies with ps accuracy, how we attacked 100 FPGA cloud instances and how we can protect FPGAs against such DOS attacks.