[dpdk-dev] [PATCH v2 0/2] AVX2 Vectorized Rx/Tx functions for i40e

[Richardson, Bruce]

> -----Original Message-----
> From: John Fastabend [mailto:john.fastabend at gmail.com]
> Sent: Tuesday, January 9, 2018 4:31 PM
> To: Richardson, Bruce; Zhang, Qi Z; Xing, Beilei
> Cc: dev at dpdk.org; Zhang, Helin; Yigit, Ferruh
> Subject: Re: [dpdk-dev] [PATCH v2 0/2] AVX2 Vectorized Rx/Tx functions for
> i40e
> 
> On 01/09/2018 06:32 AM, Bruce Richardson wrote:
> > This patch adds an AVX2 vectorized path to the i40e driver, based on
> > the existing SSE4.2 version. Using AVX2 instructions gives better
> > performance than the SSE version, though the percentage increase
> > depends on the exact settings used. For example:
> >
> 
> Hi Bruce,
> 
> Just curious, can you provide some hints on percent increase in at least
> some representative cases? I'm just trying to get a sense of if this is
> %5, 10%, 20%, more... I know mileage will vary depending on system, setup,
> configuration, etc.
> 

Best case conditions to test under are using testpmd as that is where any IO improvement will be most seen. As a ballpark figure though, on my system while testing testpmd with both 16B and 32B descriptors, (RX/TX ring sizes 1024/512) I saw ~15% performance increase, and sometimes quite a bit higher, e.g. when testing with 16B descriptors with larger burst sizes. 
As you say system, setup, config all has an impact, so YMMV... :-).

/Bruce