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by Mikael
Thu Sep 19, 2019 8:57 pm
Forum: Advanced users
Topic: Raspberry Pi4 EEPROM update package - beta
Replies: 57
Views: 7713

Re: Raspberry Pi4 EEPROM update package - beta

timg236 wrote:
Thu Sep 19, 2019 8:51 am
Yep, 2019-09-10 with the SDRAM power savings is now the default version and a critical update.
I don't have a power meter to measure the difference. Can you give us an estimate on how much this lowers the power consumption?
by Mikael
Mon Sep 09, 2019 12:30 pm
Forum: Troubleshooting
Topic: VLI firmware v2.0 - powersaving features enabled
Replies: 102
Views: 14042

Re: VLI firmware v2.0 - powersaving features enabled

Flashed and tested for temperature changes. Idle temps approximately 3C cooler with official case and top off and around 5C cooler with the top on. In absolutes:

Without top: 58C idle
With top: 67C idle

Ambient: ~22C

No issues so far, but haven't really done much.
by Mikael
Thu Aug 29, 2019 11:24 am
Forum: General discussion
Topic: Raspberry Pi 4 overheat : why not underclocking a little ?
Replies: 24
Views: 3647

Re: Raspberry Pi 4 overheat : why not underclocking a little ?

My guess is that the Cortex-A72 cores generate only a very small amount of the heat at idle. Therefore, trying to underclock and undervolt them further will have very limited effect. It's likely that any meaningful idle power consumption reductions will need to come from the RPF in the form of firmw...
by Mikael
Sun Aug 25, 2019 7:35 pm
Forum: Troubleshooting
Topic: RPI 4 - broken twice
Replies: 21
Views: 1008

Re: RPI 4 - broken twice

You're right, of course. Those Fs should have been Cs. And I know 55C isn't an issue, but the Flirc case was quite warm. Probably OK, but warmer than I was comfortable with. Since the whole point of the Flirc case is to act as a heatsink, it’s literally supposed to get hot. The hotter it gets, the ...
by Mikael
Sat Aug 10, 2019 1:17 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 105471

Re: Raspberry Pi 4 Thread - general discussion

In the UK, all four CPU cores maxed out raised the temp from 54C at idle to 68C after about ten minutes. That's with NO fan! With a full desktop running and a few web browser tabs. Heavy use of NEON will make it hotter (see the cpuburn stress test). My Pi 4 runs at around 60C idle on the Raspbian d...
by Mikael
Thu Jul 18, 2019 7:41 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 temperature
Replies: 564
Views: 183934

Re: Raspberry Pi 4 temperature

Somebody has done a neat review/comparison on the newly released ice tower cooler linked earlier in the thread https://www.youtube.com/watch?v=RyUXC3886Ic So, looks cool but is completely unnecessary, as expected. While the Pi 4 gets pretty hot, the thermal load is still very low (usually less than...
by Mikael
Tue Jun 25, 2019 1:43 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 105471

Re: Raspberry Pi 4 Thread - general discussion

This is an awesome release and every bit as good as you could expect. Congratulations to everyone involved! Really looking forward to tinkering with my 2GB version once I get it. EDIT: And to be honest, I can hardly believe some of the criticism I've seen here and on Reddit (although most people see...
by Mikael
Wed Apr 03, 2019 9:30 am
Forum: General discussion
Topic: Pi 4 questions
Replies: 166
Views: 11266

Re: Pi 4 questions

The Spectre side-channel attacks rely on speculative out-of-order execution of untrusted code. Since the unfortunate desire to run JavaScript in a web browser is unlikely to go away, it could be useful to have some in-order cores on which to run the untrusted code. These are available in the little...
by Mikael
Tue Apr 02, 2019 12:36 pm
Forum: General discussion
Topic: Pi 4 questions
Replies: 166
Views: 11266

Re: Pi 4 questions

I'm an embedded systems engineer myself and it's a fun game trying to guess what the next Pi will be (NOTE: Not making wish lists! :D). I see people suggesting big-little type setups, but I don't really think that makes any sense. For a cell phone? Yes. For a Pi? Not really. Big-little type setups a...
by Mikael
Thu Mar 31, 2016 10:18 am
Forum: Gaming
Topic: An emulator input lag investigation
Replies: 4
Views: 5075

Re: An emulator input lag investigation

Interest here seems nonexistent, so please see the Libretro forums for futher discussion and updates: http://libretro.com/forums/showthread.php?t=5428
by Mikael
Wed Mar 30, 2016 2:14 pm
Forum: Gaming
Topic: An emulator input lag investigation
Replies: 4
Views: 5075

Re: An emulator input lag investigation

I take you are using the libretro cores for those emulators, right? It's not clear because you say that you use RetroPie on the Pi (and I don't know or have interest in knowing what backends it uses, which is of great importance). If so, do you mind me taking this post to the libretro forums for di...
by Mikael
Tue Mar 29, 2016 8:07 am
Forum: Gaming
Topic: An emulator input lag investigation
Replies: 4
Views: 5075

An emulator input lag investigation

After playing a lot of old NES/SNES games on my Raspberry Pi 2 (and 3) using RetroPie, I got interested in investigating how much input lag there is in the system. The games simply seemed much harder to control than I could remember. So, I set out comparing RetroPie on the Raspberry Pi 3 to RetroArc...
by Mikael
Mon Mar 07, 2016 8:32 am
Forum: General discussion
Topic: Benchmarking a raspberrypi compared to my own PC [obsolete and locked]
Replies: 51
Views: 19149

Re: Benchmarking a raspberrypi compared to my own PC

Thanks for figuring out what was going on. I've updated the code for prime.c so that the size of the integers is specified explicitly using the stdint.h header. I've also sorted the table of timings for different processors so that it reflects which timings correspond to the use of 32-bit integers ...
by Mikael
Sun Mar 06, 2016 10:52 am
Forum: General discussion
Topic: Benchmarking a raspberrypi compared to my own PC [obsolete and locked]
Replies: 51
Views: 19149

Re: Benchmarking a raspberrypi compared to my own PC

Just posted this in another thread, but it's really important for this thread as well: gcc seems to generate sub-optimal code when compiling this program to a 64-bit binary. I used Ubuntu 15.10 32-bit for my first tests. I just tried it on 64-bit and the result for my 6700 changed "slightly": Core i...
by Mikael
Sun Mar 06, 2016 10:47 am
Forum: General discussion
Topic: Pi3 speed compared to Pi2
Replies: 91
Views: 17255

Re: Pi3 speed compared to Pi2

Bingo! I just discovered why some of you are getting such slow results! gcc seems to generate sub-optimal code when compiling this program to a 64-bit binary. I used Ubuntu 15.10 32-bit for my first tests. I just tried it on 64-bit and the result for my 6700 changed "slightly": Core i7-6700K: 1.82 s...
by Mikael
Sun Mar 06, 2016 8:42 am
Forum: General discussion
Topic: Pi3 speed compared to Pi2
Replies: 91
Views: 17255

Re: Pi3 speed compared to Pi2

The reported i7-6700K 4.0 GHz speed of 0.6 seconds seems surprisingly fast to me. While it is a different compiler using additional -msse2 -mfpmath=sse optimization settings, it would be great if someone else with similar hardware could obtain similar timings. Alternatively, could the test could be...
by Mikael
Sat Mar 05, 2016 10:36 am
Forum: General discussion
Topic: Pi3 speed compared to Pi2
Replies: 91
Views: 17255

Re: Pi3 speed compared to Pi2

Yes, sadly my 4GHz Ivy Brtidge (core i7 3770) took 2.14 seconds, but it does things like large software builds much faster, about six times as fast as the Pi3. I actually think there might be some compiler difference at work here. The i7-3770 @ 4GHz should perform much better than that in this test...
by Mikael
Sat Mar 05, 2016 8:34 am
Forum: General discussion
Topic: Benchmarking a raspberrypi compared to my own PC [obsolete and locked]
Replies: 51
Views: 19149

Re: Benchmarking a raspberrypi compared to my own PC

Cool, comparing with my desktop, an AMD Athlon X2 215 running at 1.5GHz in 64bit Ubuntu. Found a total of 664579 primes! real 0m4.400s user 0m4.389s sys 0m0.004s Found a total of 664579 primes! real 0m4.406s user 0m4.398s sys 0m0.000s Found a total of 664579 primes! real 0m4.397s user 0m4.393s sys ...
by Mikael
Fri Mar 04, 2016 9:01 pm
Forum: General discussion
Topic: Pi3 speed compared to Pi2
Replies: 91
Views: 17255

Re: Pi3 speed compared to Pi2

I ran the prime test discussed above on my Raspberry Pi 3 and Core i7-6700K, just for fun. :) For those who don't know, the i7-6700K is based on Skylake, Intel's latest architecture, and runs at 4.0-4.2 GHz. Raspberry Pi 3: 3.61 s (gcc 4.9.2, -O3 -mcpu=cortex-a53) Core i7-6700K: 0.60 s (gcc 5.2.1, -...
by Mikael
Fri Mar 04, 2016 8:58 pm
Forum: General discussion
Topic: Benchmarking a raspberrypi compared to my own PC [obsolete and locked]
Replies: 51
Views: 19149

Re: Benchmarking a raspberrypi compared to my own PC

Tested on Raspberry Pi 3 and Core i7-6700K, just for fun. :) For those who don't know, the i7-6700K is based on Skylake, Intel's latest architecture, and runs at 4.0-4.2 GHz. Raspberry Pi 3: 3.61 s (gcc 4.9.2, -O3 -mcpu=cortex-a53) Core i7-6700K: 0.60 s (gcc 5.2.1, -O3 -msse2 -mfpmath=sse) Ubuntu 15...
by Mikael
Wed Feb 11, 2015 12:40 pm
Forum: General discussion
Topic: SD Card Benchmarks
Replies: 301
Views: 293918

Re: SD Card Benchmarks

Here's a decent one for you. It's a Samsung Pro 32GB µSDHC UHS-I card fresh out of the box. It was tested in my 2013 MacBook Air running Windows 7, with its built-in card reader (which hangs on USB3 internally). It performs really well, but it will obviously not be as fast in the Pi. I have a brand ...

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