4 ms·
I guess Raspberry Pi 3 B+ (or CM3+) was close to the sweetspot in terms of thermal management vs performance tradeoffs, for many applications. Unless you really
by tpmx 7y ago
I guess Raspberry Pi 3 B+ (or CM3+) was close to the sweetspot in terms of thermal management vs performance tradeoffs, for many applications. Unless you really need more RAM or higher USB speed.
I hope the next two main steps for the next Raspberry Pi (4+ or 5?) and the corresponding compute module will be:
a) including a SATA controller (SD cards are not... ideal.)
b) a more power-efficent node
- imglorp 7y agoAlso, if your job allows, you can grab a stack and spread the load out among them. I call such a Pi stack a "bakery".
- tpmx 7y agoOk.
- timw4mail 7y agoReally the 3B was probably the sweet spot. The 3B+ still benefits considerably from a heat sink.
- tpmx 7y agoThe compute modules have a different behaviour: We're using the CM3+ on carrier boards. It's substantially better in terms of thermal performance than the CM3.
- sorenjan 7y agoI don't think a SATA controller makes sense for them. Keeping the price low is an important design goal, and adding more chips goes against that. An external hard drive with USB3 is probably the best option for a while.
- tpmx 7y agoI'd start looking at actual volume prices for controller chips first, before dismisssing this, but that's just me. I have no idea what the cost is, but I could imagine it to be like maybe 5-10 cents by now. Just a guess. It's that kind of old but still very useful tech by now.
- tpmx 7y agoBtw: Since we needed to interface to SATA reliably via USB (from a raspi CM.) We ended up identifying a particular Taiwan-designed JMicron-based SATA/USB2 controller that worked really reliably with Linux, unlike, say every single PRC-designed SATA/USB2 controller chip we tested. It was a pretty painful experience going through all of that testing. We bought 120 retail packages of that JMicron-based product, directly from the Taiwanese producer, just to be sure, to guarantee our first-gen production run. I think many RasPi users want a reliably high-speed, low-cost storage device. It doesn't make much sense for all of these users to have go through this very annoying process. It should just work. Since the chip cost for this by now is likely very small in the raspi kind of volume, why not?
- nlfwhulsdhouv 7y agoNothing of that complexity is 5-10c in volume (even huge volumes). I would guess somewhere in the 1-2$ range, which _is_ a big issue for them. For reference, 5-10c won't even buy you a middle to low performance op-amp. The Pi became possible because of integration, where the SoC supported all the required interfaces internally so very few external ICs were required. That's what allows them to keep the price so low. Additional chips add significant additional cost. That's why there have always been compromises like the USB-connected ethernet. They can only do what the SoC supports natively.
- tpmx 7y agoExactly how certain are you of this? Keep in mind that this is a 10+ year old problem by now (talking about USB2-to-SATA). They've gone through all of the cost cutting methods possible by now. I can buy that chip that also happens to come with a PCB, a very nice extruded and anodized alumunium case, plastic end-pieces + screws, indication LEDs, voltage regulators, 10-20 pieces of small passives (redistors/caps), a screwdriver, 2-3 pieces of instrution manuals/warranty notices, two layers of very nicely designed paper packaging + shrinkwrap... all for like $5 in retail. The cost to the retail store for these items is probably closer to $2. (Oh, and there's also the assembly cost for that PCB inside the case.)
- beatgammit 7y agoI doubt SATA is that expensive, and honestly they could alternatively throw in PCIe instead of SATA if that's less expensive, and it would also be way more general. I'm considering getting a Rock64Pro because it's reasonably well supported and has a PCIe port, which means I can buy a SATA add-on board. I wish Raspberry Pi had better support for fast storage.
- sorenjan 7y agoRemember that the new Pi 4B has USB3, and according to the benchmark posted on their site it can read from an SSD over USB at 363 MB/s, and write at 323 MB/s. That's pretty good, I don't think you'll get much better than that with a SATA chip connected to the same SoC, so a regular external hard drive with USB3 is probably the best option for most Raspberry Pi customers. The Rock64Pro is probably a great board too, and it also has USB3, so it can do both options. There's some Odroid boards that have built in SATA as well. https://magpi.raspberrypi.org/articles/raspberry-pi-4-specs-benchmarks https://magpi.raspberrypi.org/articles/raspberry-pi-4-specs-...
- adontz 7y agoI'd rather welcome onboard bootable MMC.
- tpmx 7y agoThat would certainly be a way for the foundation to go all Apple, with 3-4 different storage amount levels. I don't like it. Caveat: I think it makes sense that all RPI5 boards (except the lite Compute Modules) would have like 8-16GB onboard flash, via eMMC. If it makes sense, economically speaking. I think it could. The SD card aspect of the RPI sucks in so many ways.
- izacus 7y agoExcept that MMC versions of RPi already exist and it didn't really bring the world down. They're also significantly more reliable due to lack of horrible SD cards.
- tpmx 7y agoThose MMC versions are called RPI compute modules. They didn't "bring the world down" because they required a separate board for them to be mounted on.
- OJFord 7y agoWith the 4 you can use a USB3-SATA. I don't know if it can boot from a USB device though?