I want to setup RAID1 on my NUC6i7KYK.
I have two 960 Pro NVMe drives, and have just read the https://www.intel.com/content/www/us/en/support/articles/000021493/mini-pcs/intel-nuc-kits.htmlhttp:... RAID Setup doc.
For SATA (AHCI) RAID it shows stripe size changed from 16KB to 128K, but
for NVMe it leaves it at 16KB.
Is there an optimal size for PCIe transfer?
For HDDs, larger stripe sizes make sense because contiguous writes improve performance. For SSDs, this makes less sense. Of course, you file size mix can make a difference as well. Really, if you want this to be optimal, you should run some tests at different stripe sizes and determine what makes the most sense. If it was me and I had to make a quick decision, I would stick with 16KB.
Hope this helps,
I got the following email, unfortunately replying to it didn't work, hence this post.
I would like to know if you still need assistance regarding your thread /thread/125182 NUC6i7KYK PCIe (NVMe) RAID - ideal stripe size? or if it is OK for me to close the case?
My failed email reply:
Well I haven't created the array yet, so yes I would like an Intel considered answer.
Is 16K optimal for NVMe PCIe RAID?
p.s. For example, given the NTFS 4K Allocation Unit with compression uses 64K chunks, it would seem 32K would spread chunks across two discs.
But PCIe and NVMe architecture may also be involved.
I imagine someone has looked into this?
EDIT: BTW Advice for future readers, I haven't created the RAID array yet, as one created you lose visibility of the drives for things like firmware upgrades, so I'm doing that first.
Hello, Michael@Oz. Thank you very much for your reply.
In this case, if you will be storing a big amount of data it will be better to use higher stripe sizes on the other hand, if you will not be storing a lot of data it is recommendable to use less stripe size. We recommend using the default stripe size.
Perhaps I can paraphrase my question.
Has Intel studied the performance of RAID configurations with M.2 NVMe drives?
I can't be the first person.
In a past life I was Technical Director overseeing datacenter storage in Defence. I would have expected Intel or any vendor to have looked into such issues.
OK, I give up.
Hello, Michael@Oz. Thank you for your prompt response.
Indeed we have run some tests and, as previously mentioned, we recommend using the default stripe size for home use.
Hello, Michael@Oz. I would like to add something else to this topic:
On a system such as NUC6i7KYK with capacity for only 2 drives and with possibly smaller drives available (compare to Server Drives), the impact created by setting smaller vs larger stripe size is very unnoticeable. This is more of a feature you will be concerned about on a server system but it does not make much of a difference in the desktop space. In fact, this feature is often overrated, as the performance changes are marginal on a typical gaming or office PC.
Allow me to mention that if you are planning to create a RAID array for quick access/small files, a small stripe size will be beneficial. This will provide higher throughput thanks to a high level of data distribution across many drives but in this case, the system is limited to only 2 drives so, the benefit is very little noticeable.
On the other hand, for systems running file servers for photos, audio, and video - meaning larger files, larger stripe sizes are recommended, as this helps to maximize sequential read performance. My recommendation, especially on a server, will be to do some experimentation with various options: both small and large stripe size and compare performance. I would recommend avoiding making little changes like going from 32 kB to 64 kB stripe size won't have a significant impact.
Thanks for the additional info, however it is now moot.
I prior to configuring RAID I upgraded all firmware.
The RAID config now does not have a stripe size option, so I presume it is optimal.
Or perhaps in a pure PCIe basis, packet sizes at the various serial buses, is irrelevant.
I don't recall, but have not rechecked, that change being mentioned in the release notes.
BTW, this is for RAID1 for redundancy, but I am expecting some boost on reads.
The higher workloads will be CAD, 3D rendering & video editing.