The Raspberry Pi 2 Q&A thread

[gkreidl]

I have a Raspi model B like NAS. And I have a usb Harddisk write speed about 7 MB/s. The harddisk is EXT4.

Is the RASPI 2 faster?

I don't believe that your write speed is really that low. I get about 27-29 MB/sec.

Maybe you mean write speed across a samba network. And that should really be near the limit of 10-11 MB/sec with s Pi2, because the faster processor can handle the protocol overhead much better.

[Elnef]

I have a Raspi model B like NAS. And I have a usb Harddisk write speed about 7 MB/s. The harddisk is EXT4.

Is the RASPI 2 faster?

I don't believe that your write speed is really that low. I get about 27-29 MB/sec.

Maybe you mean write speed across a samba network. And that should really be near the limit of 10-11 MB/sec with s Pi2, because the faster processor can handle the protocol overhead much better.

Correct. I use Samba.

[rurwin]

1.we see win10 is on the way, is there any plan on android yet?
2.any further information on DSI TFT?
3.power consumption between the model b+ and pi2?

1. Android depends on there being willing volunteers to do the work. That won't be organised by the Foundation (so far as I know.) IIUC, and I'm not an Android techie, it should be easier work on the ARMv7 but it won't be trivial.
2. No further info, but the RaspPi 2 still has the connector. I believe work is proceeding, but I don't know at what pace.
3. In the Element14 Q&A, Ebon said that the RaspPi 2 takes about the same power as the B. The extra cores take about the same amount of power as was saved with the more efficient power regulation on the B+.

So someone else mentioned that windows 10 may be a cut down version or have no GUI? Is it not possible to just install a regular copy of windows 10 on this thing onto a usb or the Micro SD?

Good question. Given that this "Windows 10" thing is turning out to be just a bad joke (for a variety of reasons), the relevant question is: Is the new Pi powerful enough (CPU, RAM) to run real (x86) Windows (not any version of this "10" abomination) effectively under some emulator (e.g., QEMU, etc) ?

That's the real question.

No. Given the 1.8-2x speed increase, we might expect to get an x86 emulation about equivalent to a 120MHz '486.

1GB of memory is not enough for any recent versions of Windows, and you'll only have a fraction of that available for an emulator.

Windows 95 may run fairly cleanly, but of course it wouldn't be licensable.

[joan]

In "Raspberry Pi 2 - FAQ and collated answers - Is it really 100% backwards compatible?" a call to get the base address at run-time is mentioned. What is this call? Does it also give the translation from physical to bus addresses?

[jamesh]

In "Raspberry Pi 2 - FAQ and collated answers - Is it really 100% backwards compatible?" a call to get the base address at run-time is mentioned. What is this call? Does it also give the translation from physical to bus addresses?

Reason I didn't add that to the FAQ is that I don't know the exact details, but will find out!

[croston]

@joan - this should help

https://github.com/raspberrypi/userland ... 2ca631f0e9

[raspberry_user]

Anybody knows the exact size and weight of this new product?

[jamesh]

Anybody knows the exact size and weight of this new product?

Size is the same as the B+, weight I've not measured, but will be very similar, maybe a gram or two heavier.

[fishxz]

will there ubuntu desktop aviable soon for the rpi 2? as i understand it should be possible to run the desktop version on a armv7?

[joan]

@joan - this should help

https://github.com/raspberrypi/userland ... 2ca631f0e9

If it works it would appear to be the best method. I must admit bcm_host_get_sdram_address doesn't leap out as a method of getting the physical to bus memory translation.

Have you used those functions? They seem to require a library bcm_host which I can't find.

Currently I've hard coded the base address and bus translation.

[outcave]

Hi.
What is the BUS (I mean Raspberry Pi 2 board side) of the MicroSD slot?
Is it High Speed (v. 2.0) or UHS-I (v. 3.01) or UHS-II (v. 4.00)?


(See here: http://en.wikipedia.org/wiki/Secure_Digital#Speeds)

Thanks!

[jdb]

Hi.
What is the BUS (I mean Raspberry Pi 2 board side) of the MicroSD slot?
Is it "High Speed" or "UHS Speed Class 1 (U1)" or "UHS Speed Class 3 (U3)"?

(See here: http://en.wikipedia.org/wiki/Secure_Digital#Speeds)

Thanks!

SDR50 (~22MB/s max), same as all the other models.

[rahlquist]

Has anyone tried to benchmark the USB and NIC?

People in the know seem to be indicating a performance improvement may occur due to the beefier cpu.

Could someone perhaps run iPerf to test the bandwidth of the NIC and maybe a couple file transfers over usb? MCM still lists mine as "Processing" cant wait till I get it.

Thanks!

[blachanc]

Can anyone comment or evaluate the impact on VNC or RDP user experience ?

My son always complained about the user experience even whith an overclocked B+

PS:
I ordered 2 PI2 on Monday 10AM EST (4PM UK), but do not expect to get them before all early morning Europe orders are fulfilled.
April I guess...

Ben

[dom]

Have you used those functions? They seem to require a library bcm_host which I can't find.

Try /opt/vc/lib (or clone userland and run the build script).

bcm_host_get_sdram_address will give the bus address of physical address zero, so yes, add that to phyical address to get a bus address (suitable for bus mastering peripherals like DMA, or the GPU).

[joan]

Have you used those functions? They seem to require a library bcm_host which I can't find.

Try /opt/vc/lib (or clone userland and run the build script).

bcm_host_get_sdram_address will give the bus address of physical address zero, so yes, add that to phyical address to get a bus address (suitable for bus mastering peripherals like DMA, or the GPU).

Thanks. Of course I found the answer two minutes after posting. Forums have been down since.

[psergiu]

question is: Is the new Pi powerful enough (CPU, RAM) to run real (x86) Windows (not any version of this "10" abomination) effectively under some emulator (e.g., QEMU, etc) ?

No. Given the 1.8-2x speed increase, we might expect to get an x86 emulation about equivalent to a 120MHz '486.

Anyways it will run much faster than on the original 256Mb RPi http://www.raspberrypi.org/forums/viewt ... 14&p=79171

[Fidelius]

Will a single-threaded Java program, i.e. Java Byte Code running in a Java Virtual Machine, run faster on the Pi2's ARM7 (with no Jazelle) than on the Pi1's ARM6 (with Jazelle) ? Or slower? Leaving the obvious quadcore speed-up aside for a moment...

I am asking since the Pi1's got an „ARM1176JZF-S“ (with an ARM6) which has ARM's hardware Java Byte Code accelerator named Jazelle. Is this the reason why Java programs run so reasonably fast on the Pi1 taking into account its not-so-fast ARM6?

However the Pi2's „Cortex-A7“ (with an ARM7) hasn't got the Jazelle anymore. So no Java Byte Code acceleration in hardware.
But, maybe a modern JVM like the Raspbian's Oracle Java8 uses an ARM7 so well that the Jazelle is obsolete? I think that has been the case since years for CISC processors like the AMD/Intel ones.

[DougieLawson]

Anyways it will run much faster than on the original 256Mb RPi http://www.raspberrypi.org/forums/viewt ... 14&p=79171

Only if it can be persuaded to run on more than a single thread. Else, you'll get about 9/7ths of current speed (+/- overclocking).

[PhilE]

Even single threaded, at the same clock speed, the more efficient core and large L2 cache will make Pi2 quicker. Plus, having another core to run the things which aren't your application can make quite a difference.

[PuppetHoundZ]

Once we do some performance comparisons (v6 versus v7 compiled libraries/binaries etc) then we may decide to:
- Have a v6 userland as performance improvements are negligible
- Have a hybrid v6 / v7 userland that takes advantage of parallelism at the library level (dynamically selected at boot-time)

I hope one of the above is done. Cross-compatibility for SD cards is key with open source stuff like this, try a program here and then test on older version and trouble shoot. One could create a intense game on New Pi that can run on Old . Don't become like Sony and Microsoft where they abandon previous users (which I know won't happen but I must say that.).

That being said, I hope this new Pi creators/hackers will still continue to develop software for the lowest common denominator like older Pis. (Ie. I hope Epiphany will utilize more of the GPU Videocore IV so that Raspberry Pi B+ users who haven't been able to get hold of the new Pi Yet can still see performance enhancements.).

Question: Was keeping the Videocore IV GPU set in stone, so that there would be cross-compatibility for the Pi's or was it more of an issue of the GPU still having untapped performance when it comes to OS utilization?

Question 2: Also will the utilization of the new Pi2 CPU allow for users to play a full version of Minecraft using Ubuntu or is the OpenGL ES thing still preventing it?

Question 3: I noticed that the new Raspbian image has some overclocking settings for Pi2. If I select this setting on a older Pi what could happen?

[SteveOll]

My PC motherboard died last summer and I used my model B+ board until it was replaced and I thought to myself at the time if only the PI was faster I could live without my desktop PC...

Anyway I jumped at the chance to order the PI 2 only yesterday from CPC in Ireland (approx EUR 47.00 delivered) and it arrived today.

I got Noobs and installed Raspbian and the speed increase is very obvious - especially when installing applications - on the B+ the CPU would be at 100% load, whereas the PI 2 didn't go above 37% and that was installing LibreOffice!

The web browsing seems a bit faster, but as I am in rural Ireland, and the broadband here is not so good I can't tell for sure, but if you are in a city it's probably much improved.

Oh and by the way I have the full Minecraft 1.6.11 installer currently downloading the game to my PI 2!!!! fingers crossed that it will launch successfully. I'll keep you updated!

[PuppetHoundZ]

Oh and by the way I have the full Minecraft 1.6.11 installer currently downloading the game to my PI 2!!!! fingers crossed that it will launch successfully. I'll keep you updated!

Keep us posted! If it plays legit MC this will change the world for Children that use the Pi. Not only will they be able to program and learn they can take some legit MC brakes. Also MC full version only uses 500mb of ram so make sure you have at the most 256MB allocated for GPU!

[rurwin]

Anybody knows the exact size and weight of this new product?

I knew I bought that cute digital scale for a reason.

I make it 41.8g

[Mequa]

Can I over clock the new Raspberry Pi 2 model B? Can I overclock it to 1.2ghz or higher? I was wondering this because windows 10 is quite intensive especially on a Raspberry Pi and overclocking would make windows run smoother.

I don't have a Pi2 yet, unfortunately. However on the Pi1 after a "sudo apt-get update & apt-get dist-upgrade" the program raspi-config (which I use to overclock the Pi1 to perfectly stable 1,000 MHz aka "Turbo" mode), shows this new entry at the bottom :

Code: Select all

Chose overclock preset                                   
                                                         
None    700MHz ARM, 250MHz core, 400MHz SDRAM, 0 overvolt 
Modest  800MHz ARM, 250MHz core, 400MHz SDRAM, 0 overvolt 
Medium  900MHz ARM, 250MHz core, 450MHz SDRAM, 2 overvolt 
High    950MHz ARM, 250MHz core, 450MHz SDRAM, 6 overvolt 
Turbo  1000MHz ARM, 500MHz core, 600MHz SDRAM, 6 overvolt
Pi2    1000MHz ARM, 500MHz core, 500MHz SDRAM, 2 overvolt

I tried the Pi2 1000MHz overclock on my new Pi 2, and Raspbian kept freezing up (I used the latest image, not NOOBS). It has been stable since I disabled overclock.

This means one of two things: My Pi 2 cannot physically do a stable overclock to 1GHz, or a firmware or some other software update (and/or improved power supply) should make this possible some day.


I also noticed that RISC OS Pi is not currently compatible with Raspberry Pi 2. The same with OpenELEC, and possibly other OS's. Will these be updated to support the new Pi 2, including with a new NOOBS image, I am wondering?

I am also wondering whether NutPi will be supported on a version of RISC OS Pi compatible with Raspberry Pi 2, given how this commercial RISC OS software was locked to the Raspberry Pi hardware.