3 ms·
SD card performance on the Pi <4 is so poor (and the bandwidth is shared with the USB controller anyway, I think) that you might as well use an attached USB har
by joshvm 7y ago
SD card performance on the Pi <4 is so poor (and the bandwidth is shared with the USB controller anyway, I think) that you might as well use an attached USB hard disk; even for booting.
Jeff's benchmarks are accurate in my experience. If you try saving single images from a camera at even 5-10fps, the card quickly bottleneck and you start dropping frames. If you buffer and store (in my case 16-bit raw), you can essentially saturate USB bandwidth if you're also using a USB camera.
- geerlingguy 7y agoYeah I'm always fighting both write speed and network speed limitations when I do timelapse projects with my Pi Zeros. Hopefully the I/O improvements from the 4 trickle down to the Zero form factor sometime soon!
- sgt 7y agoWe've got a few Pi's in office "production" (used as dashboards) and the best solution we've found it to use an SSD drive via USB. Something like a 128GB SSD drive is cheap enough, although it's about as expensive as the Pi itself.
- Vogtinator 7y agoNo, the bandwidth isn't shared as both sd controllers (sdhci and sdhost) are directly accessible using MMIO (and DMA).
- joshvm 7y agoThanks for clarifying that, I was never sure.