I have an 8TB Desktop Archive drive from Seagate (the ones that are suppose to be slow on write I believe). I am just wondering if adding this is a bad idea and will hurt performance of the array. I already have 8x 8TB NAS HDDs, 1x 3TB Desktop HDD and 6x 4TB Desktop HDDs in my array. I also have 2 512GB Samsung 850 Evo Pro SSDs for cache drives. I generally would have no problem adding the drive but wanted to see anyone had experience with this drive and if it has caused any issues with performance.

I have several of these drives and they work quite well.

 

Writes are slow to the SMR, the disk has a large (200G?) "PMR cache" that must full up before the slowdown is realized. While the disk is idle is moves the PMR cache to the SMR.

 

Note that sequential writes do not go through the PMR cache, but write to SMR at full speed. Do you'd need to be writing in a more random way to engage the PMR cache. Maybe if a disk is heavily fragmented with lots of adds and deletes of smaller files, and then suddenly you are copying a lot of data to it, you could create a situation where the "wall" would be hit.

 

I personally have never experienced the slowdown, even filling up an 8T at full speed.

 

I can't imagine this will slow down anything. But run some tests and find out. If you said you had an array fully of 8T or 10T 7200 RPM drives, it might slow down things a tad, but with your mix of drive sizes I would be surprised if you'd notice much difference.

Thanks for the help!