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I wonder if they are thermally capable of sustaining a high CPU load. Phones strike me as fairly bursty in terms of compute usage; I'm curious if running them
by curryst 7y ago
I wonder if they are thermally capable of sustaining a high CPU load. Phones strike me as fairly bursty in terms of compute usage; I'm curious if running them hot for a long period of time would damage the phone.
- mirimir 7y agoDoesn't watching streaming video use considerable CPU?
- lostmsu 7y agoVideo decoding is usually implemented in hardware, so very efficient.
- mirimir 7y agoSure, GPU. But do phones have gaming-level GPU? So what do phones normally do with their CPU?
- lostgame 7y agoAFAIK video decoding generally has its own chip, at least for supported codecs, separate from the GPU.
- mirimir 7y agoCan those things be exploited for other purposes?
- craftinator 7y agoSure. I've used the H264 encoder/decoder in lossless mode on the raspi3 compress large amounts of sensor data. You just need to format the data into image frames. It worked very well, and ended up being bottlenecked by the io bandwidth of the system.
- mirimir 7y agoDoes raspi3 have real gigabit Ethernet?
- masklinn 7y agoNo, that's a headline feature of 4. 3B+ has a GigE adapter working over USB2 so you can get ~200Mbps, on other models you can get an off-board adapter providing much better performances than the on-board one but still not "real GigE": https://www.jeffgeerling.com/blogs/jeff-geerling/getting-gigabit-networking https://www.jeffgeerling.com/blogs/jeff-geerling/getting-gig...
- lostgame 7y agoI’m not sure, that’s a great question. Practically, I’m not sure how that could be of use but I have seen some amazing things come out of the several processors in, for instance, SEGA Saturn homebrew, with chipsets certainly making innovative unintended uses, or at least insanely creative use. Here’s an example of what an H.264 decoder chip would be like: https://www.digikey.ca/en/product-highlight/s/system-on-chip-technologies/h264-hd-video-or-video-audio-encoder-decoder-modules https://www.digikey.ca/en/product-highlight/s/system-on-chip...
- jbverschoor 7y agoThe iPhone cpu/gpu is crazy fast.
- Spooky23 7y agoNo, they have dedicated chips or instructions for H264/265. In general, the advantage of faster phones is that they are idle a lot more.
- Narishma 7y agoThe same things PCs do with their CPUs and GPUs. There are no differences here. The video decoder is part of the SoC, along with the CPU, GPU, memory controller and tons of other stuff.
- mirimir 7y agoWhat I'm getting at is that single-user machines that host multiple VMs don't actually use much more CPU than they would if they ran what the VMs in aggregate are running. The main difference, from a resource usage perspective, is that each VM needs RAM. I typically run at least two pfSense router VMs as VPN gateways. They use about 600MB each. And the Debian VM that I'm writing this in uses about 2.4GB. Most of that's used by the browser. But CPU usage is only about 10% of four 3GHz i5 cores. But if I stream some video, or download a torrent, all three VMs use more CPU. Altogether maybe 50%-60% CPU. That's because there are thee OpenVPN instances (one in the host, and one in each pfSense VM) encoding/decoding traffic. Even so, I doubt that it'd be all that different if there were no VMs, and the host was doing all that. In other words, I don't think that the VirtualBox overhead is all that high.
- lostmsu 7y agoThere is something wrong with your setup, as 3x encrypted video streams should not take that much CPU, and neither should video decoding.
- masklinn 7y ago> Sure, GPU. Not GPGPU no, dedicated decoding blocks in the SoC. That's why getting hardware support in the phones is a Big Deal for video codecs (audio as well, to a somewhat lesser extent but support in the audio decoding block means audio playback can happen completely off CPU and let it sleep). > But do phones have gaming-level GPU? Not in the "modern PC gaming-class GPU". They have efficient GPUs but simply don't have the physical, thermal or energetic headroom. In GFLOPS, higher-end phone GPUs are roughly where desktop GPUs were 10 years ago or so (though obviously there are other factors like texturing units and the like).
- jotm 7y agoAs VR headsets/adapters have proven, yes, most phones will overheat with continuous usage.
- mirimir 7y agoThey should have tiny fans in them. Or maybe just heat pipes with cooling fins. Back in the day before SSDs, I used to cool external HDDs with axial fans during TB-scale operations.
- zozbot234 7y agoThere are phones that are built with better cooling, such as ASUS's ROG series. If not for the substandard (and with unclear guarantees) support period, the ASUS ROG could be a true 'flagship' device, even for non-gamers.
- jessaustin 7y agoA dock could include a thermostatically-controlled cool surface that the phone rests against.