2.5" SSD Advice

[ChrisLoudon]

Hi guys,

 

I am currently using a Samsung QVO 4TB SSD for a cache drive in my Unraid NAS but I am finding my write speeds tank to about 20MBs when working with larger files.

 

Does anyone know of a suitable replacement drive that will keep its write speeds high regardless of file size?

 

A few other members on this forum have suggested QVO drives tank like this.

 

The platform is an older Z77 mobo so no m.2 or NVme so I'm limited to Sata 6Gbs 2.5". 4TB would be ideal.

 

Cheers

[johnt]

I don't think SATA or NVME matters in this case. The more budget friendly drives tend to run out of cache very quickly. And what's kind of sad, in your case, the SSD can't even keep up with SATA speeds. Samsung Pro models are a good option if you want to stick with the same brand. WD Black drives are my personal go to. 

 

Otherwise look for drives with a large cache.

[YoungBlade]

That's a result of using QLC NAND. Once the SLC cache is exausted, and it has to write directly to the QLC, the performance is going to suffer massively.

 

As far as I know, all of the TLC 4TB drives these days are NVMe drives. You could get a PCIe adapter for that. They do also make NVMe to SATA enclosures, but they're pricy as they need to convert between NVMe and SATA protocols.

 

You can look at this 990 Pro 4TB review to see the other 4TB drives they tested against. All of them have sustained speeds of at least 1GB/s after their cache is exhausted. https://www.tomshardware.com/reviews/samsung-990-pro-4tb-ssd-review/2

 

Limited to the PCIe 2 of that old motherboard, combined with CPU overhead, any of those drives would probably never even exhaust their cache, so would just give you sustained write speeds indefinitely.

[ChrisLoudon]

1 hour ago, YoungBlade said:

That's a result of using QLC NAND. Once the SLC cache is exausted, and it has to write directly to the QLC, the performance is going to suffer massively.

 

As far as I know, all of the TLC 4TB drives these days are NVMe drives. You could get a PCIe adapter for that. They do also make NVMe to SATA enclosures, but they're pricy as they need to convert between NVMe and SATA protocols.

 

You can look at this 990 Pro 4TB review to see the other 4TB drives they tested against. All of them have sustained speeds of at least 1GB/s after their cache is exhausted. https://www.tomshardware.com/reviews/samsung-990-pro-4tb-ssd-review/2

 

Limited to the PCIe 2 of that old motherboard, combined with CPU overhead, any of those drives would probably never even exhaust their cache, so would just give you sustained write speeds indefinitely.

Thanks for the info buddy, very useful.

 

I think I'll either look at a PCIe adapter card for NVMe devices or maybe just keep what I've got and live with it. Its only when I decided to do a big reshuffle of my data that this happens and its not a frequent task.

 

On a similar note, why would be read speeds suffer? I'm currently in the process of running the 'mover' task in Unraid to get everything off the cache and on to the storage array and i'm currently watching paint dry at 30ish MBs

[YoungBlade]

37 minutes ago, ChrisLoudon said:

Thanks for the info buddy, very useful.

 

I think I'll either look at a PCIe adapter card for NVMe devices or maybe just keep what I've got and live with it. Its only when I decided to do a big reshuffle of my data that this happens and its not a frequent task.

 

On a similar note, why would be read speeds suffer? I'm currently in the process of running the 'mover' task in Unraid to get everything off the cache and on to the storage array and i'm currently watching paint dry at 30ish MBs

Is this big files or small ones? Small files will always have slow move times when you move a bunch of them, because the percent of time spent on filesystem overhead with accessing and creating the new file becomes the bottleneck, rather than transfer speeds.

[ChrisLoudon]

23 minutes ago, YoungBlade said:

Is this big files or small ones? Small files will always have slow move times when you move a bunch of them, because the percent of time spent on filesystem overhead with accessing and creating the new file becomes the bottleneck, rather than transfer speeds.

Naaa, this is large 70ish GB files.

 

It could just be Unraid being slow as its writing parity but my system resources like memory and cpu usage aren't spinking or red-lining at all.

 

Strange thing is, the mover starts and the transfer speeds report upwards of 150MBs then I come home from work to find its plummeted to 30MBs and still got hours to go.

[kokosnh]

there are MX500 4TB, and 870 evo 4TB form  4TB SATA SSD, on TLC, and good speeds.

 Question is, do you want to go SATA.