@ RoSchmi -
that is DMA buffer, I am sure this is not the one we were talking about. It will be another story if we talk about DMA.
I also don’t think they calculate the max speed bases on DMA buffer.
We are very far from the topic 
@ RoSchimi,
That’s when you’re using DMA (i.e. external memory). Technically you could achieve the same thing by implementing a software buffer in your program (like I’m doing).
Good to know those buffer sizes btw; I’m going to adjust the program so it’ doesn’t try to send 1400 bytes again 
Regarding the event that is raised when SerialPort dtaa is received; when does the event get raised? When the data arrives or when the data stops coming? If it is when it stops coming then how much time before it is triggered.
(I really need to look into the low code for these things but I just don’t know how to start).
@ Mr. John Smith -
You need to install NETMFPorting Kit, download open source code of Cerb family
it is usually located on 2 files:
C:\MicroFrameworkPK_v4_2\DeviceCode\pal\COM\usart\uart.cpp
BOOL USART_Driver::AddCharToRxBuffer( int ComPortNum, char c )
and
C:\MicroFrameworkPK_v4_2\DeviceCode\Targets\Native\STM32\DeviceCode\STM32_USART\STM32_usart_functions.cpp
@ Dat, I know this is a painful point, but is there a thread that would get a person up to speed on recompiling and deploying the porting kit and the cerb family code onto a cerb device?
Search the forum. There are a couple of good threads about community version of the firmware and how to build it.
Kewlio.
Hello, I’m using Fez Spider board with USB-Serial Module. I’m getting upload speed about 23 kB/s, using 460800 Baudrate and 5kB packets. When i try to transmit larger packet, about 1/3 - 1/2 of the bits is lost during the transmission. Using smaller Baudrate I can transfer larger packets, but it decreases speed. I tried 921600Bauds but transmission hangs, except if the packet length is smaller than ~40 bytes. I’d like to get speed at least 100kB/s speed. Is that possible? I made a rework on the USB module to enable RTS and CTS but it doesn’t help.
@ Lubomir Krzeminski - It would be best to post your own thread about this issue.