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DE2i-150 PCIe slow throughput

Altera_Forum
Honored Contributor II
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[EDIT: Please disregard this post, as it was a double post. Consider checking this one out instead http://www.alteraforum.com/forum/showthread.php?t=49314

 

Hello, 

I wonder if someone could please help me. I'm using an Avalon-MM DMA for interfacing between my host application and the FPGA SDRAM. The thing is, I can't get more than 10MB/s throughput for read/write operations. My host code is quite simple (pseudocode): 

 

int i; char* data = (char*)malloc(128MB); //or some other value. 128MB is what I've got on my DE2i, so that's the maximum value allowed here. for(i = 0; i < 128MB; ++i) data = rand(); time = clock(); DMAWrite(SDRAM_ADDR, data, size(128MB)); DMARead(SDRAM_ADDR, data, size(128MB)); total time = clock() - time; throughput = 128MB/total time;  

 

My qsys design is also very simple: 

http://www.alteraforum.com/forum/attachment.php?attachmentid=10952&stc=1  

Full img: http://1drv.ms/1ovvaw3 

 

I'm using the Jungo driver provided on the demonstrations of the SystemCD of the board. 

 

Am I missing something? Can I improve the system performance? 

 

I need a somewhat bigger throughput, something around 90MB/s at least, but any possible improvement is welcome. 

 

Many thanks.
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