Raspberry Pi Forums

lingon

Are the OpenSSL assembly optimizations available somewhere or will they be included in the Debian Wheezy Beta release as an update?

lingon

lingon, what kernel and firmware version are you using for the UHS-1 card? How does booting fail (at what stage, and if applicable, what kinds of errors)? If you used the Wheezy image as-is, a manual update of kernel and firmware might help. Today I upgraded to the Debian Wheezy Beta uname -a Linux...

lingon

I applied the linked optimization patch to the openssl package and rebuilt it. All build tests passed so it looks like it is good and should be in our public repository by Sunday evening. Did you happen to run openssl speed with the ARM optimized packages? With my Raspberry Pi overclocked to 900 MH...

lingon

I upgraded the Wheezy image to the new firmware and kernel. It runs great on a Transcend 8 GB Class 6 150X card. /dev/mmcblk0p1: Timing cached reads: 288 MB in 2.01 seconds = 143.27 MB/sec Timing buffered disk reads: 56 MB in 2.91 seconds = 19.26 MB/sec /dev/mmcblk0p1: Timing O_DIRECT cached reads: ...

lingon

<t>Chromatix said: BTW, UHS-I cards are *always* Class 10 cards. UHS-I has Class 10 performance as a prerequisite, and mandates a few other things too. So if there is any failure mode specific to Class 10 cards, there's a good chance it will also apply to UHS-I cards. ...

lingon

<t>Swap space will be needed in many cases on the Raspberry Pi. The most important use for a good SD-card with fast reads and writes is as swap space in addition to the other things I listed in my post above. Some cameras support UHS-I class SD-cards, so the prices will come down as for flash in ge...

lingon

<t>Chromatix said: What I've heard from reliable sources is that the bootloader is apparently unable to read some high-speed cards reliably. It's really not clear how many cards are affected by this, only that "most" Class 10 cards are potentially problematic. This is a...

lingon

<t>Thanks Chromatix for your testing! A SanDisk Extreme Pro 8 GB SD card looks like a good choice now that it is known that the Raspberry Pi SD controller can support UHS-I speeds. The latest USB 3.0 card readers seem to support UHS-I speeds as well, which would allow for testing if you h...

lingon

<r>Great news to have the BCM2835 data sheet available! Thanks to all authors who have taken the time to put this nice book together! On page 82 it says UHSMODE Select the speed mode of the SD card: RW 0x0 000 = SDR12 001 = SDR25 010 = SDR50 011 =...

lingon

<r>Have you noticed that the openssl performance on the beta boards from this page posted by Paul Maunders <URL url="http://pastebin.com/xUBaiQnk">http://pastebin.com/xUBaiQnk</URL> sign verify sign/s verify/s rsa 512 bits 0.006262s 0.000622s 159.7 1607.2 r...

lingon

<r>This is an interesting post at Phoronix about a new Linux I/O scheduler FIOPS under development for flash memory: <URL url="http://www.phoronix.com/scan.php?page=news_item&px=MTAzOTU"><LINK_TEXT text="http://www.phoronix.com/scan.php?page=n ... px=MTAzOTU">http://www.phoronix.com/s...

lingon

Here is a table of fast SD-cards listed by their specified transfer speeds:

http://hjreggel.net/cardspeed/....._sdxc.html

Benchmark results for these fast cards would be even more interesting to see of course.

lingon

<r>The pictures of the beta boards shows the RAM to be Hynix H9TKNNN2GDMPLR-NDM which is of type 800 MHz DDR2: <URL url="http://www.hynix.com/inc/pdfDo.....Memory.pdf">http://www.hynix.com/inc/pdfDo.....Memory.pdf</URL> In theory the RAM bandwidth is 3,2 GB/s. The latency is al...

lingon

<r>[quote]<s>[b]</s>Quote from johnbeetem on November 26, 2011, 15:06<e>[/b]</e> My interpretation of the current Gerber plot: It\'s a top side view, but there are discrete components like capacitors, resistors, and diodes on the bottom side. The top side silkscreen is not shown in...

lingon

<t>It is great to have an idea of how the final board will look like, so thanks to the team for sharing it. If one looks more carefully at the image one can easily see that all texts describing the components are mirrored. So I would guess that the picture shows the view from below of the card....

lingon

I agree that it would be nice if the website header would be smaller. This is especially true if I read it from a 320*240 pixel phone screen.

lingon

<r>How well motion will run on the Raspberry Pi will depend largely on the resolution and frame rate that you want to achieve with your camera. An idea of the needed CPU power can be found from this page <URL url="http://elinux.org/BeagleBoardUbuntu">http://elinux.org/BeagleBoardUbuntu</URL><br...

lingon

I would also prefer a silent computer at startup. Those who want a noisy bootup could add it to their bootup scripts.

lingon

<t>Quote from dom on September 28, 2011, 21:19 The key option is -mfpu=vfp, but you get that as standard if you use the cross-compiler (bcm2708-gcc). That improves the results to: ./whetstone Loops: 1000, Iterations: 100, Duration: 106 sec. C Converted Double Precision Whets...

lingon

<r>It can be done with VNC even with simple Java phones, but the screen size is clearly the limiting factor. <URL url="http://www.freeutils.net/vnc2go/">http://www.freeutils.net/vnc2go/</URL> I have not tried the program above on my phone, but I guess it is a bit awkward to use with a smal...

lingon

<r>That other thread is about something slightly different than what I would like to have answered in this thread. A standard SD card can give a maximum read speed of less than 20 MB/s and then achieving a good write speed is about tuning for flash memory constraints. What I would like to know here ...

lingon

Is there any news on what the maximum transfer speed the SD reader will be and what speed the ARM core interface itself supports?

lingon

<t>I think that these standard flash optimizations should be done, for they will largely determine the subjective speed of the system for the users, when launching and using applications. In general a slow CPU with a slow disk is a bad combination, but a slow CPU and a reasonably fast disk is quite ...

lingon

To get a good performance with dd it is important to increase the blocksize to a reasonable amount. Please look up this page for details and suggestions:
http://www.joescat.com/backup/....._fast.html

lingon

<t>Cheap flash memory is nice for reads because of the low latency, but writing is limited by the fact that you have to erase a block of 128 kB or more in the worst case to flip a single bit. To have acceptable write performance in spite of the problem of write amplification it is advisable to decre...

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Re: OpenSSL assembly optimizations

Re: SD Card performance in R-Pi onboard slot

Re: OpenSSL assembly optimizations

Re: SD Card performance in R-Pi onboard slot

Re: Class 10 SD cards on the production boards

Re: Whats the max speed of the SD card slot ?

Re: Class 10 SD cards on the production boards

Re: Class 10 SD cards on the production boards

Re: Whats the max speed of the SD card slot ?

Re: OpenSSL benchmarks

Re: Optimizing Linux for Flash memory.

Re: Optimizing Linux for Flash memory.

Re: Whats the max speed of the SD card slot ?

Re: Finalised PCB design now on the front page

Re: Finalised PCB design now on the front page

Re: Web site header

Re: Raspberry pi as autonomous surveillance system

Re: Raspberry Pi Bootup Sound Discussion

Re: Floating point performance?

Re: Using a mobile phone as a remote desktop display

Re: Whats the max speed of the SD card slot ?

Re: Whats the max speed of the SD card slot ?

Re: Data Transfer Performance Figures

Re: Data Transfer Performance Figures

Re: Data Transfer Performance Figures