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Altera_Forum's avatar
Altera_Forum
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11 years ago

Slow transfer speeds PCIE Gen3

Hi all, I was working on a design using Stratix V Avalon-ST PCIE Hard IP Gen3 and I get quite varying results. With one machine I can get a consistent high speed PCIE Gen3 and managed to get tr...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

6.0GB/s for Gen 3x8 for both read and write seems reasonable.

For the machine that get a slow throughput, it could be the link was trained to gen3 intially but was later downtrain to lower speed (gen1 & gen2 only). Try minitor currentspeed signal continuously to ensure the link not downtrain.

Also can try to monitor the LTSSM to ensure the link does not goes to Recovery state too often.