Even Canada post has online tracking LOL . I received a book last week and was able to track it online. It showed me the delivery date and even send me a email when it was delivered to my community mail box. 15 minutes later I picked it up .
Well, $50 US is not really a discount... The RPi 2 sells for $35 US at MCM Electronics, though backordered with a 10 day expectation for getting them into MCM's warehouse. I assume Newark/Element 14 will sell for $35 US as well. Elector's retail of $58 US seems quite high.
Even Canada post has online tracking LOL . I received a book last week and was able to track it online. It showed me the delivery date and even send me a email when it was delivered to my community mail box. 15 minutes later I picked it up .
Yes, but I was told by RS they were out of stock yesterday, and the on-line tracking didn't work although they were being shipped. It did work today, though. The card they left said to wait a day.
Thank you for your excellent reviews on everything Pi! I've enjoyed reading each of them and appreciate the amount of thoughtful work and analysis that you've put into them.
There are a lot of benchmarks comparing Pi 2 B, Pi B+, Odroid C1, Banana Pro, MIPS Creator CI20
Cool, - no Baud rate tests I could see ?
A useful test I use on PCs for stress-testing USB & Serial ports, is to send a large file of 0x55 ("U") and a Frequency Counter on the DATA lines gives the sustained average throughput.
Tested in both Loop-back, and open ended modes.
At low baud rates, freq is Data/2 on Std 8 Bit UART, and at higher rates extra stop bits can creep in from the system delays, lowering the Frequency below Data/2.
Gapless SPI will also hit Data/2, but some SPI ports need 1 Baud clk turnaround, and some need 1-2 SysClk turnaround, and the better ones can do gapless SPI.
Baud Granularity is also easily found on this test setup - ask for slightly incrementing Baud values, and see when the Frequency actually changes. This will give a Virtual Baud Clock value ( eg on most FTDI parts, the VBC is 12MHz )
jmg: thanks. Nope, no serial, spi or i2c tests. Might try some later, to see how far I can push the Pi/RoboPi data rate
Bob: Than you! Yep, the Pi 2 is surprisingly snappy. I am pretty sure they shaved/tuned the boot sequence, and stripped the binaries, as the C1 *should* be faster for boot/launch times, but is not.
I got a box today with three RasPi 2's in it. One is going to be set up as a workstation. I've always run them headless, so this should be interesting. I do wish they had SATA. A RasPi 2 with a 128gb SSD would be a sweet workstation. I guess that's a job for my Banana Pro.
I have one tool I need to get to my virtual desktop at work that needs an x86 OS. If it wasn't for that, I could totally run my world on these little guys.
"I've just seen a clean rectangle wave out of the TX pin at 4 megabaud, that is 2 MHz when sending "UUUUUUUUUU...."
and another comment there of After reading around, I did some testing to see what the maximum achievable baud rate is. Using the latest stable raspbian build (3.6.11+) and editing init_uart_clock in /boot/config.txt, I was able to get up to 4Mbaud read speeds. However, past that point it seems that the linux OS stops support, as bits/termios.h has __MAX_BAUD at 4Mbaud (http://repo-genesis3.cbi.utsa.edu/cross ... .html#:172).
I would think that going up to 15.6Mbaud would be feasable, considering that baud_rate=250MHz/(8*(1+baud_reg)),
That 250MHz CLK is not a good fit for higher speeds, as FTDI use a virtual Baud CLK of 12MHz or 24MHz, whilst the 2 formula given on RaspPi give 15.625Mhz or maybe 31.25MHz, meaning that 4MBd mentioned will be
3.906250MBd, which is a 2.34% offset from what FTDI will deliver.
Maybe the System PLLs can be tweaked to give better Baud rate alignment ?
All those numbers will likely move on the 4 Core model.
but I'm at a loss as to what to do to get past the 4Mbaud limit.
Sounds like 4MBd (sustained) has been achieved, and up to 15.625MBd mayU be possible
Comments
http://www.elektor.com/news/Raspberry-Pi-2-Model-B/?utm_source=Elektor+International+%28English%29&utm_campaign=65ccd86028-107EN2_6_2015&utm_medium=email&utm_term=0_23bd160f48-65ccd86028-234065433&mc_cid=65ccd86028&mc_eid=b3483591d2
re: so I called in at the PO\
Don't they have online tracking?
Even Canada post has online tracking LOL . I received a book last week and was able to track it online. It showed me the delivery date and even send me a email when it was delivered to my community mail box. 15 minutes later I picked it up .
Well, $50 US is not really a discount... The RPi 2 sells for $35 US at MCM Electronics, though backordered with a 10 day expectation for getting them into MCM's warehouse. I assume Newark/Element 14 will sell for $35 US as well. Elector's retail of $58 US seems quite high.
dgately
Yes, but I was told by RS they were out of stock yesterday, and the on-line tracking didn't work although they were being shipped. It did work today, though. The card they left said to wait a day.
Yes, your right. I did not realize how high it was until you pointed it out and I saw that it did not include shipping and handling.
http://www.mikronauts.com/raspberry-pi/raspberry-pi-2-model-b-review/
There are a lot of benchmarks comparing Pi 2 B, Pi B+, Odroid C1, Banana Pro, MIPS Creator CI20
Thank you for your excellent reviews on everything Pi! I've enjoyed reading each of them and appreciate the amount of thoughtful work and analysis that you've put into them.
Bravo!!
I really liked how you compared it to the ODroid C1 as I am also looking at that for my setup.
Thanks for taking the time to do these!
Cool, - no Baud rate tests I could see ?
A useful test I use on PCs for stress-testing USB & Serial ports, is to send a large file of 0x55 ("U") and a Frequency Counter on the DATA lines gives the sustained average throughput.
Tested in both Loop-back, and open ended modes.
At low baud rates, freq is Data/2 on Std 8 Bit UART, and at higher rates extra stop bits can creep in from the system delays, lowering the Frequency below Data/2.
Gapless SPI will also hit Data/2, but some SPI ports need 1 Baud clk turnaround, and some need 1-2 SysClk turnaround, and the better ones can do gapless SPI.
Baud Granularity is also easily found on this test setup - ask for slightly incrementing Baud values, and see when the Frequency actually changes. This will give a Virtual Baud Clock value ( eg on most FTDI parts, the VBC is 12MHz )
Start up time looks good too."" Raspberry Pi 2 B ADATA 22.9"" (not that I'm impatient LOL)
jmg: thanks. Nope, no serial, spi or i2c tests. Might try some later, to see how far I can push the Pi/RoboPi data rate
Bob: Than you! Yep, the Pi 2 is surprisingly snappy. I am pretty sure they shaved/tuned the boot sequence, and stripped the binaries, as the C1 *should* be faster for boot/launch times, but is not.
I have one tool I need to get to my virtual desktop at work that needs an x86 OS. If it wasn't for that, I could totally run my world on these little guys.
You might want to start a separate benchmarks thread.
I also found this, for older RaspPi I think
http://www.raspberrypi.org/forums/viewtopic.php?f=44&t=43442
that seems to indicate a HW based Virtual SPI clock of 250MHz and Baud = VSC/(2*N)
Practical speeds could be in the region of 25MHz / 31.25MHz / 41.666MHz / 62.5MHz
and also this for UARTS ?
http://www.raspberrypi.org/forums/viewtopic.php?f=44&t=17559
Mentions 100MHz as a pin ceiling, & someone else said
"I've just seen a clean rectangle wave out of the TX pin at 4 megabaud, that is 2 MHz when sending "UUUUUUUUUU...."
and another comment there of
After reading around, I did some testing to see what the maximum achievable baud rate is. Using the latest stable raspbian build (3.6.11+) and editing init_uart_clock in /boot/config.txt, I was able to get up to 4Mbaud read speeds. However, past that point it seems that the linux OS stops support, as bits/termios.h has __MAX_BAUD at 4Mbaud (http://repo-genesis3.cbi.utsa.edu/cross ... .html#:172).
I would think that going up to 15.6Mbaud would be feasable, considering that
baud_rate=250MHz/(8*(1+baud_reg)),
That 250MHz CLK is not a good fit for higher speeds, as FTDI use a virtual Baud CLK of 12MHz or 24MHz, whilst the 2 formula given on RaspPi give 15.625Mhz or maybe 31.25MHz, meaning that 4MBd mentioned will be
3.906250MBd, which is a 2.34% offset from what FTDI will deliver.
Maybe the System PLLs can be tweaked to give better Baud rate alignment ?
All those numbers will likely move on the 4 Core model.
but I'm at a loss as to what to do to get past the 4Mbaud limit.
Sounds like 4MBd (sustained) has been achieved, and up to 15.625MBd mayU be possible