Hi Ernest,

The answer depends on many different factors – the IOPs limit per device, CPU core frequency, Turbo, etc.  As a frame of reference, the team here at Intel has measured over 3M IO/s on a single Intel Xeon core[1].

-Jim

[1] https://www.flashmemorysummit.com/English/Collaterals/Proceedings/2016/20160809_FA12_P3_Prepalli.pdf - slide 63

From: SPDK <spdk-bounces@lists.01.org> on behalf of Ernest Zed <kreuzerkrieg@gmail.com>
Reply-To: Storage Performance Development Kit <spdk@lists.01.org>
Date: Thursday, February 15, 2018 at 6:46 AM
To: Storage Performance Development Kit <spdk@lists.01.org>
Subject: [SPDK] Number of NVMe devices per core

Hi All,

I ran 'perf' with different settings to see how to get most of NVMe disks. I see that performance degrades once cpu mask puts more than 2 devises per core. Is it OK? what is the theoretical (or empirical) limit of devices one core can handle? 

Sincerely,

Ernest