Raspberry Pi 2
David Pitt (102) 743 posts |
That’ll be CloneDisc which is now asking for a Product Key on the RPi2. |
GavinWraith (26) 1530 posts |
I wrote an article in May 2013 for PiAddict (requiescat in pace) on different algorithms for calculating the first 200 values of the Fibonacci series, with timing comparisons. Here are comparisons for two of them between the Iyonix and RPi2 (clocked at 1Ghz): Iterative method:
Iyonix = 76 cs, RPi2 = 38 cs Lazy tables:
Iyonix = 19 cs, RPi2 = 19 cs Not quite sure what to make of these figures. |
Kuemmel (439) 383 posts |
@Jeffrey: Nice ! So is that already there now in the nightly built ROM and David or others could test my VFP and NEON Fractal code ? Or do I need a change in my initialisation code ? |
David Pitt (102) 743 posts |
Yes, both work. |
GavinWraith (26) 1530 posts |
I preferred to use cabled keyboard/mouse on the RPi because with the Logitech wireless ones it was evident that not all the signals were getting through. However the wireless setup seems much better with RPi2, and means one fewer USB port taken up. I hope this is not just my imagination. Has the USB software been improved? |
Eric Rucker (325) 232 posts |
Could have been better USB power? Raspberry Pis, especially early ones, have had a lot of trouble with power-hungry USB devices. |
Kuemmel (439) 383 posts |
@David: Could you post the results ? The VFP one should also work on the Pi 1 I guess. |
David Pitt (102) 743 posts |
RPi2 RPi1 900MHz 700MHz FracNEON_Basic 2.02(s) Undefined instruction 25 FracVFP_Basic 3.24(s) SWI &1000D now known 25 |
Jeffrey Lee (213) 6044 posts |
The Pi USB driver hasn’t seen any significant improvements for the past 7 months. Whether that’s newer than the ROM you were using previously, only you can confirm! |
Kuemmel (439) 383 posts |
@David: I updated my VFP code (same link as before), should run on both, thanks to Jeffrey (the Pi 1 has only half of the Dx registers, and I didn’t do the right VFP Initialisation for that, without even needing them all). Of course the NEON won’t run at all as the Pi 1 doesn’t have that extension. Pi 2 looking good at NEON, but clock by clock about 40% less efficient than the Cortex A9 in the Panda. Still good to have that now, could speed up a lot of floating point stuff if in use and brings it up to date. |
GavinWraith (26) 1530 posts |
It is newer. I just discovered this works on the RPi2:
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David Pitt (102) 743 posts |
Hmm! That got me the same version as before.
In the absence of actual expertise I halved R1 to 16 in the call to VFPSupport_CheckContext in Line 75. That worked in 8.22s on the RPi1 at 700MHz compared to 3.26s on the RPi2 at 900MHz. |
Kuemmel (439) 383 posts |
…weird…I thought I corrected and uploaded everything…can you send me a personal message (michael.kuebel ed googlemail.com), so we can sort that out ? Also my non-PI !MemSpeed app I think could run now on the Pi 1 with that R1=16 adaption in the code I guess (have to check myself and would send you that by mail to confirm later). |
David Feugey (2125) 2687 posts |
Damned, you have a one by one line decoder for this? :) |
GavinWraith (26) 1530 posts |
If you mean line by line disassembly then:
is what I think you want. But if you try it in BASIC at the moment you will get no such mnemonic . |
David Feugey (2125) 2687 posts |
Cool. Thanks :) |
Rick Murray (539) 13351 posts |
Okay. It’s been ten days. How does the Pi 2 stack against the Pi (and the Beagle/xM)? I don’t mean in terms of benchmarks, I mean in use. Does it boot much faster? Does it feel more fluid in use? Does it look and feel like an OMAP3? Has anybody used the two side by side? What are the good points (today; multi-core is in the future)? What are the bad points (other than being camera shy)? Has anybody tried other parts of Noobs? I use RasbBMC from time to time on my Pi and it is fairly slick once it has booted (except when updating itself, that takes forever) but I found the Linux distro (Raspbian?) to be a bit lethargic. Has this changed? Do four cores make a better experience? The Pi2 is now within reach of Ubuntu. Is it like Ubuntu on a PC, or is it a reduced build (like xubuntu)? How does that feel? Any plans to bring Android to the Pi2? [can’t say that an IoT version of Windows is terribly exciting, to be honest!] We’ve had benchmarks and tests and I’m grateful to those who have supplied the figures; however numbers don’t quite convey how the new hardware feels in use. Hence my questions. ☺ |
DaveH (2604) 2 posts |
Can someone confirm that I have performed the correct steps to run the nightly build on the Pi 2? With the firmware from GitHub it has gone from no output to giving the full screen multicolour square I believe you get before RISC OS starts, but stops at this stage. Now my SD card has arrived, I had visions of spending the night playing Chocks Away! (under ArcEm). I look like I’m close but missing one vital step. One thing that does bother me is the original RISCOS.IMG was 5Mb in size, where as the replacement is 2.5Mb. |
David Pitt (102) 743 posts |
Has it really, how time flies by when one is having fun.
The Pi2 is noticeably faster than the Pi1, it shows straight away in that screen redraws are just that bit slicker. Overall the processing speed increase is around 30% to 40% but the disc drive performance remains as before, slow that is. Just before the Pi2 was announced I had been considering if the A9home would be a better, less sluggish, option than the Pi1. The two machines are roughly similar performers, the A9home’s processor is slower but the drive is faster. The Pi2 is excellent at RISC OS type things and a good way of participating in the OS5 fun, but heavy lifting is best done elsewhere, VRPC on an iMac in my case. 30 quid well spent, + µSD. |
David Pitt (102) 743 posts |
I guess this is a typo, but START/ELF?
The current ROM is indeed 2.5MB. I have found in the past that some cards just don’t work but seem correct when seen on the iMac. |
GavinWraith (26) 1530 posts |
The rainbow square low-voltage warning is a useful innovation (B+ and RPi2). I noticed it was on all the time, so I switched the Logitech wireless-kbd/mouse dongle from a USB port on the RPi2 to one on the USB hub. The rainbow square went away. On the original RPi I could not use the wireless-kbd/mouse without losing lots of keypresses, so the USB software has been improved. Yes, the RPi2 feels faster. It is a joy to use. I have noticed one oddity concerning SparkFS (1.41 20-Oct-2004) on the RPi2. Some spark files or zip files it will not open (at first), saying Bad Archive . The readonly version has no problem with those files. So I was able to dearchive their contents and then rearchive with SparkFS. The resulting files were slightly larger but were now readable. I did not come across this problem on the Raspberry Pi B. |
David Pitt (102) 743 posts |
SparkFS 1.43 (02-Sep-2012) is Pi perfect here. |
DaveH (2604) 2 posts |
> I guess this is a typo, but START/ELF? No, I had missed that one. Many thanks I’m up and running now. Two successful missions on Chocks Away and it takes me back. Next challenge working out how to image my copy protected Extra Missions disk. Google and blue skies await! |
Chris Mahoney (1684) 2093 posts |
It looks like 1.43 is the minimum version required, as the release notes specifically mention ARMv7 compatibility. Edit: The 1.42 notes also say that! But in either case it looks like 1.41 is too old. |
GavinWraith (26) 1530 posts |
I had the upgrade to 1.43 all the time and had overlooked using it. All working fine now. |