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Altera_Forum
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14 years ago

Question about PCIe speed

I have been working on the chaining DMA example project for PCIe provided by Altera. I am a bit confused about what performance I should expect though. When sending 16.384 GBytes of data f...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

What do you mean by PC memory speed?

I looked at the amount of RAM used during the DMA's, there's plenty of free memory, so it doesn't seem like a bottleneck.

I'm sending the data to the driver from a C code using fwrite and fread functions (to read/write from/to the driver's file), I don't think they would slow the system down.

I'm not sure where the problem could be.

Also, I'm still not sure whether the 5.0Gbps is one or two-way. If it's two-way, then the problem might just be that I'm doing a DMA write followed by a read, followed by a write etc..., instead of launching both a DMA read and a DMA write at the same time (if that's possible).