Matrox Rapixo CL Pro, Installation And Hardware Reference, Page: 58 / 96

58 Chapter 4: Matrox Rapixo CL Pro hardware reference
Host interface
The Matrox Rapixo CL Pro PCIe 2.0 Host interface is capable of high-speed
DMA transfers to Host memory, or other memory mapped onto the PCIe bus
that are compliant with the PCI Express Base Specification, rev 2.1. The DMA
write engine of the Host interface is capable of performing the transfers without
the help of the Host CPU.
Matrox Rapixo CL Pro uses PCIe 2.0 technology to communicate with the Host.
Under optimum conditions, Matrox Rapixo CL Pro can send data to the Host at
a peak transfer rate of up to 4 Gbytes/sec. Optimum conditions include using the
board in a PCIe 2.x slot or above with 8 active lanes, using a 256-byte payload.
DMA write performance is chipset and computer dependent, and is slightly
affected by the image size and alignment in Host memory.
The Matrox Rapixo CL Pro Host interface has four DMA write contexts, which
act independently, simulating four DMA write engines running in parallel. The
presence of multiple DMA contexts does not change the maximum bandwidth,
but can help reduce latency.