[wmf]

reading directly from a PCIe device, such as an NVMe flash, can actually be faster than caching things in RAM first.

That's not true though, because the PCIe device DMAs into RAM anyway.

[nine_k]

No, it can DMA straight into L3 cache, as mentioned in the article.

See https://www.intel.com/content/www/us/en/io/data-direct-i-o-t...

[wmf]

Your server doesn't have DDIO turned on though.

[nine_k]

Not mine, but fair!