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by lb
Fri Nov 22, 2019 10:53 am
Forum: Advanced users
Topic: DVFS Firmware
Replies: 58
Views: 5190

Re: DVFS Firmware

Cool stuff! I've been waiting for this. After all there has been various commits in the past that pointed to ongoing work. :) I don't have a Pi 4 handy right now, does anyone have any numbers, e.g. current draw, before and after in idle and mixed load states yet? There's some power stuff in this ar...
by lb
Fri Nov 22, 2019 10:35 am
Forum: Advanced users
Topic: DVFS Firmware
Replies: 58
Views: 5190

Re: DVFS Firmware

Cool stuff! I've been waiting for this. After all there has been various commits in the past that pointed to ongoing work. :) I don't have a Pi 4 handy right now, does anyone have any numbers, e.g. current draw, before and after in idle and mixed load states yet? Edit: for anyone interested, I found...
by lb
Thu Sep 12, 2019 10:27 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

Has anyone checked yet how much of a difference the new bootloader firmware (not the VLI firmware) makes? It changes some of the SDRAM programming and promises to reduce power consumption.
by lb
Tue Aug 13, 2019 11:29 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

We've got some SW changes coming that might help with idle temperatures (won't help with pathological cases like cpuburn, but that not something you encounter in general usage) but for general use will hopefully drop the average temperature. Not sure when they are due though, there will be somethin...
by lb
Sun Aug 11, 2019 9:20 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

Then perhaps you should stop making bold (and false) statements, such as... I agree that this was misleading. What I was going for is that typical cases that even slightly reduces convection and airflow (so basically all standard cases, even half-open ones), you will have major issues with the Pi 4...
by lb
Sun Aug 11, 2019 8:51 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

I remember there were some plans to reduce (idle) power consumption with software changes to the DRAM controller or the graphics driver. Are we going to see anything in this regard any time soon? And what happened to the VLI firmware update, are there any further updates coming out? If you have any...
by lb
Fri Aug 09, 2019 6:20 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

I remember there were some plans to reduce (idle) power consumption with software changes to the DRAM controller or the graphics driver. Are we going to see anything in this regard any time soon? And what happened to the VLI firmware update, are there any further updates coming out? If you have any ...
by lb
Mon Jul 08, 2019 9:59 am
Forum: Advanced users
Topic: eMMC in place of SD
Replies: 2
Views: 767

Re: eMMC in place of SD

SD cards and eMMC modules are quite similar. That is why these simple adapters are possible in the first place. You might be interested in industrial grade SD cards as an alternative to eMMC modules. These often use SLC flash with far higher endurance, have a higher temperature rating and they might...
by lb
Fri Jul 05, 2019 7:45 pm
Forum: Troubleshooting
Topic: Turning LCD backlight off on rpi4/buster with dpms
Replies: 12
Views: 1165

Re: Turning LCD backlight off on rpi4/buster with dpms

On Raspberry Pi < 4, you had to set "hdmi_blanking=1" in config.txt to get DPMS blanking to work. With that option set, it Just Works, though. I actually helped a bit to also make it work with DPI, too (at least for VGA666). Blanking is pretty good for power saving with always on setups. It doesn't ...
by lb
Thu Jul 04, 2019 11:00 pm
Forum: Troubleshooting
Topic: Turning LCD backlight off on rpi4/buster with dpms
Replies: 12
Views: 1165

Re: Turning LCD backlight off on rpi4/buster with dpms

Yes, DPMS seems to be broken on Pi 4.
by lb
Thu Jul 04, 2019 1:35 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 - new VLI firmware issues
Replies: 69
Views: 21472

Re: Raspberry Pi 4 - new VLI firmware issues

I think we might mix up problems here. As far as I can see, there are some generic issues with USB on the Pi 4 at the moment that even appear with the old firmware. These need to be fixed. Interaction with power management might exacerbate those issues.
by lb
Wed Jul 03, 2019 8:17 pm
Forum: General discussion
Topic: Raspberry Pi 4B - Mouse Cursor lag in 4k
Replies: 9
Views: 924

Re: Raspberry Pi 4B - Mouse Cursor lag in 4k

How and what is perceived as laggy is very individual. For many people, 30 Hz is horribly laggy. :)
by lb
Tue Jul 02, 2019 4:30 pm
Forum: General discussion
Topic: Fastest Micro SD card for Pi 4? Does it support XC U3?
Replies: 38
Views: 9704

Re: Fastest Micro SD card for Pi 4? Does it support XC U3?

No, you cannot overclock the SDHC interface on the Pi 4 (at least not easily). It's also not recommended or required.
by lb
Tue Jul 02, 2019 3:01 pm
Forum: General discussion
Topic: Fastest Micro SD card for Pi 4? Does it support XC U3?
Replies: 38
Views: 9704

Re: Fastest Micro SD card for Pi 4? Does it support XC U3?

What matters most is the random access performance (IOPS). So get an A1 or A2 class card if you want good performance. Apart from that, little else matters as only up to DDR50 transfer mode is supported. The Samsung card you posted does not have an A1 or A2 certification, so I wouldn't recommend it....
by lb
Tue Jul 02, 2019 9:47 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

Hi all, Following a successful trial with our alpha testers, we are releasing a new firmware build for the USB3 host adapter that should save about 300mW and help the Pi4 to run cooler, which in turn improves performance in compute-intensive tasks. Thanks. This definitely works and has a significan...
by lb
Tue Jul 02, 2019 7:34 am
Forum: General discussion
Topic: RAM issues on the new Raspberry Pi 4 - 4GB
Replies: 7
Views: 4340

Re: RAM issues on the new Raspberry Pi 4 - 4GB

That's correct, there is a per-process limit of 3 GiB. However, with multiple processes, you can still easily take advantage of all of the RAM. This is not an ARM-specific or Raspberry-Pi-specific problem. I guess it will still take some time for Raspbian to move to 64 bit, but in practice, this sho...
by lb
Tue Jul 02, 2019 6:58 am
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

We actually have some ideas to get the temperature down, currently being tested. My open air Pi is running about 6degs cooler with some test firmware (not the USB firmware, already have that installed). Cannot say that is what will come out of the other end of testing, but looks promising. So that ...
by lb
Mon Jul 01, 2019 8:51 am
Forum: General discussion
Topic: Google software encryption for pi 4 support
Replies: 3
Views: 431

Re: Google software encryption for pi 4 support

If you mean Google Adiantum, it was merged into Linux mainline in December 2018. I'm not sure which kernel version it ended up in, but we will be able to get it with a future kernel upgrade. Kernel 4.19.x, which is currently shipping, is too old. Edit: of course, you might as well just run mainline ...
by lb
Mon Jul 01, 2019 7:10 am
Forum: General discussion
Topic: RPI4, out of order and Spectre vulnerabilities
Replies: 27
Views: 2547

Re: RPI4, out of order and Spectre vulnerabilities

I don't agree: side-channel attacks are nothing new. What's new is that the bugs are on the hardware level and tricky to fix. However, it is, without significant exceptions, the consensus among OS vendors and CPU manufacturers, that the Spectre bugs are serious and have to be mitigated by default. I...
by lb
Mon Jul 01, 2019 1:16 am
Forum: General discussion
Topic: RPI4, out of order and Spectre vulnerabilities
Replies: 27
Views: 2547

Re: RPI4, out of order and Spectre vulnerabilities

No, IMO they are not a significant issue, even if the mitigation isn't built in to the kernel or the silicon. because, as above, AIUI there is no malware that uses this attack vector. Sorry, but that's a really bad argument. With this kind of reasoning, you might as well never pro-actively fix any ...
by lb
Sun Jun 30, 2019 5:21 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

It's certainly possible that power usage and thermal tunings affect performance. Some past tunings have reduced performance (on Pi 3B or Pi 3B+, don't remember which one). This also applies to the PCIe power management fixes. I think it's fine to take a small hit for significantly reduced power usag...
by lb
Sun Jun 30, 2019 5:17 pm
Forum: General discussion
Topic: RPI4, out of order and Spectre vulnerabilities
Replies: 27
Views: 2547

Re: RPI4, out of order and Spectre vulnerabilities

A72 is immune to Meltdown. A72 is vulnerable to Spectre, but this means context leakage in the same process space. The practical upshot of this is that on A72, there is yet another way to exfiltrate data from the web browser via malicious javascript - that is mitigated against quite effectively via...
by lb
Sun Jun 30, 2019 10:09 am
Forum: General discussion
Topic: Not all RPI 4's are equal?
Replies: 34
Views: 5114

Re: Not all RPI 4's are equal?

I guess it's fair to say that all shipped units are "early production" so far.
by lb
Sun Jun 30, 2019 8:38 am
Forum: General discussion
Topic: Not all RPI 4's are equal?
Replies: 34
Views: 5114

Re: Not all RPI 4's are equal?

300 mA? That's crazy. Now I really want to try this. So if you need some users to test this... ;)
by lb
Sat Jun 29, 2019 4:47 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 200957

Re: Raspberry Pi 4 temperature

I'd also be fine to be a guinea pig if Raspberry Pi developers want some people to test this advance. I can provide feedback and data.

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