Comment on TKey: A reasonably secure RISC-V computer in a USB stick
simple@lemmy.world 6 months ago
Seems like a cool project, but with such weak specs what can one actually do with this?
This thing is like 5x more MHz with 8x more RAM than an Arduino. 18MHz and 128kB is plenty.
Remember: the Apollo flight computer (Moon landing) was accomplished with 2MHz and 4096 bytes of RAM. Even the Arduino is more computationally powerful than the Moon Lander.
So, what? I’m gonna go to Mars with my USB stick RISC-V?
Any computer application you can think of from the 1970s or earlier can be replicated by a device of approximately the specs listed in this topic.
IE: Airplanes, Space Exploration, Differential Equations, Matrix Multiplications, Simulations, Cruise Missiles, Homing Missiles, Firing Computers (aka: aim-bots), RADAR, SONAR, Radio communications.
To just give you an incomplete idea of what’s possible. So erm… anything you want, really.
Oh, well in that case I’m making a USB connected sonar guided homing missile with an airbag!
arduinos run at 16 MHz
I stand corrected.
they actually could be made to run at 20 MHz with some software tweaks. But sram is still much less
dannym@lemmy.escapebigtech.info 6 months ago
The specs are literally the reason why people would buy this. It’s basically the best possible device for devices handling secure computation. Think of a FIDO2 key, or a gpg smartcard, all verifiable`
dragontamer@lemmy.world 6 months ago
Ehhhh… I’d recommend a Teensy instead, or a variety of other microprocessors. At $72, this is awful value. And there seems to be no specifications with regards to power-consumption.
www.pjrc.com/store/teensy41.html
Teensy gives you 100 MBit Ethernet, USB, 600MHz, 1024kB of SRAM for like $35 and within ~100mA of current usage at this 600MHz speed, meaning it easily runs off of AA Batteries for over a day with just a bit of idle/sleep cycles.
dannym@lemmy.escapebigtech.info 6 months ago
there are use cases, such as security, where you want as few instructions as possible, so a full ARM processor isn’t the best idea
dragontamer@lemmy.world 6 months ago
On the contrary, RISC-V is typically bigger and less efficient than Cortex-M7 on the Teensy.
There are 10-cent ARM Cortex M0+ processors (M0+ being the smallest ARM). M7 is kinda-small. ARM scales to different sizes and power-efficiencies.
Cenzorrll@lemmy.world 6 months ago
Completely different use cases
dragontamer@lemmy.world 6 months ago
How so?
The use-case is determined by power-efficiency, performance, and cost. Cost is already a loser at $72 vs $35. Performance is a loser at 18MHz vs 600MHz. What’s left is power-efficiency, but now that I know that this is an FPGA soft-core, I’m guessing the Teensy / ARM Cortex-M7 is also more power efficient.
So the Teensy is cheaper, faster, and (probably??) more power-efficient than the RISC-V soft-core FPGA implementation here.
The 8-bit uCs that I like to play with (AVR, or their competitors PIC12, Cortex M0+, Cortex M32, or TI MSP430) are all in the 5mA or less range (dramatically so: some in the 5uA range if you abuse sleep / idle states severely). These 8-bitters are closer to the performance that I’d expect of the 18MHz speed and 128kB of RAM here, but I have reason to believe that the 8-bit (and 32-bit / 16-bit competitors like Cortex M0+ / MSP430) are far more power efficient than the TKey.