Re: [SPDK] Number of NVMe devices per core

[Harris, James R <james.r.harris at intel.com>]

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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(a)lists.01.org> on behalf of Ernest Zed <kreuzerkrieg(a)gmail.com>
Reply-To: Storage Performance Development Kit <spdk(a)lists.01.org>
Date: Thursday, February 15, 2018 at 6:46 AM
To: Storage Performance Development Kit <spdk(a)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

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