QNAP SSD benefit debate

[Enquiries]

Hi there, huge fan of the channel and always detailed info that is given!
Just got a new TS-873AeU-4G-EU that I immediately upgraded with 64GB ECC and the 25GbE networking card.

I might have made a mistake on not going for a QM2 card instead since it only has one PCI port, unfortunately, but I needed the SFP for my Ubiquiti Aggregation switch haha.

Anyways, I have already put this question with QNAP that will never understand the question since they only reply with a standard response or drive compatibility. This also despite my second attempt in Mandarin since they're based in Taiwan, so I figured you might now better anyway:

I got the latest QuTS Hero version on this machine where I was wondering whether the system would benefit from putting it on the 2x PCIe NVME M.2 slots versus putting it on 2 regular SATA SSD's in the drive bays. Like; would it make a substantial difference or is QuTS not able to utilise the gen3 speeds anyway?
I do not really need caching as I know they're originally meant for this, but since I saw someone running QTS on the QM2 card, it is possible to do so.

In the specsheet they also talk about it being a Gen3x1 but there is no x1... so I assume they meant x4 (lanes).

1. So long story short: is it beneficial to put QuTS on PCIe SSD over SATA SSD's in terms of speed, or better off leaving m.2 for cache.

2. I don't understand how WD SATA SSD has almost the same pricing as the PCIe line, but offers only 6-800 TBW vs their staggering 1PB on the PCIe. Would I then also be better off buying PCIe to SATA adapter cards to also use those SSD's in the regular bays?

Massive cheers to you and your time reading this!

Best regards

[QNAPDaniel]

Hi there, huge fan of the channel and always detailed info that is given!
Just got a new TS-873AeU-4G-EU that I immediately upgraded with 64GB ECC and the 25GbE networking card.

I might have made a mistake on not going for a QM2 card instead since it only has one PCI port, unfortunately, but I needed the SFP for my Ubiquiti Aggregation switch haha.

Anyways, I have already put this question with QNAP that will never understand the question since they only reply with a standard response or drive compatibility. This also despite my second attempt in Mandarin since they're based in Taiwan, so I figured you might now better anyway:

I got the latest QuTS Hero version on this machine where I was wondering whether the system would benefit from putting it on the 2x PCIe NVME M.2 slots versus putting it on 2 regular SATA SSD's in the drive bays. Like; would it make a substantial difference or is QuTS not able to utilise the gen3 speeds anyway?
I do not really need caching as I know they're originally meant for this, but since I saw someone running QTS on the QM2 card, it is possible to do so.

In the specsheet they also talk about it being a Gen3x1 but there is no x1... so I assume they meant x4 (lanes).

1. So long story short: is it beneficial to put QuTS on PCIe SSD over SATA SSD's in terms of speed, or better off leaving m.2 for cache.

2. I don't understand how WD SATA SSD has almost the same pricing as the PCIe line, but offers only 6-800 TBW vs their staggering 1PB on the PCIe. Would I then also be better off buying PCIe to SATA adapter cards to also use those SSD's in the regular bays?

Massive cheers to you and your time reading this!

Best regards

QuTS Hero the OS does not need the faster SSD to run well. You can use the M.2 SSDs for the System pool or the SATA SSDs and the OS should run fine.
If you use the M.2  then you can have 8 HDDs for the storage pool. And if you don't use the M.2 for the System pool then you only have 6 HDDs for storage after you use 2 for the System pool.
A pool of 8 HDDs should perform better than a pool of 6 HDD because you have more drives to write to and read from at the same time. 
So M.2 System pool should perform better, not because the OS needs M.2 but because you can have more HDDs in your pool.

M.2 slots are 3X1. But You can put 4X4 and 3X4 M.2 in those slots. They just get 3X1 performance. For the System pool this should not be a problem. For L2ARC cache this would not be as ideal.

But for a lot of use cases that are more sequential L2ARC may not help much anyway. 
The most important cache in QuTS Hero is usually the RAM ARC cache and the 64GB RAM should be good for performance.