Time to increase the number of SFF drives from 24 to 32 or ?? in 2u chassis

[pgh5278]

Patrick, with the number of Enterprise SSD now 7mm, do You foresee a move to increase SFF density from 24 to 32 or higher in a 2U, as the caddies are designed to accept 15mm drives, but drives a getting thinner ( wish I could )

Guess this may require a new standard, like the 15mm was the old standard..I understand there are models which have a double row of drives now, but this is a more costly option.
Using a 2U chassis with SFF drives below..shows even designed for 9mm drives their remains plenty of space for air to flow..not that I am a thermodynamics engineer..

 

[PigLover]

There are still a lot of 15mm ssd. Pretty much all SAS ssd and the extreme scale drives like the Samsung 15.9tb drives (which also happen to be SAS).

I think the majority of chassis builders will keep 15mm support for quite a while - while some specialty chassis might appear for thinner drives.

Sent from my SM-G925V using Tapatalk

 

[cheezehead]

Don't see it happening, I could see moving to 1.8" form factor though.

 

[Patrick]

It is easier for the flash vendors to adopt NVMe and get more performance for front panel space and more internal volume for greater capacity.

The use case for up-ending current standard 2.5" caddy sizes comes down to more drives. You want more drives for performance or for capacity.

• Capacity - With smaller 7mm form factors you have less volume for NAND so you are getting capacity from more devices not larger devices. With flash, you can just do this with packing more NAND. You also want fewer disk controllers. In theory you would want 24x 15TB disks rather than 36x 10TB disks because you can remove 12 SSD controller/ RAM sets from the array.
• Performance - one NVMe SSDs has the performance of 5x SATA SSDs. If you just want low power and a small form factor for the performance you go m.2 not 2.5". If you did 36x 2.5" NVMe SSDs you would need 36*4 = 144 PCIe lanes so you end up significantly oversubscribed on the PCIe bus given today's architectures.

I do believe that is the primary reason 1.8" SSDs are not more prominent. m.2 came in with a smaller form factor and 5x the performance. Given SSD reliability, you could argue hot swap is less of a priority even.

 

[pgh5278]

Thanks, makes sense..

 

[cheezehead]

hot swap is kinda a requirement for many enterprise environments, even if the insertion rate was low.

 

[JDM]

EchoSteams does already sell ultra dense chassis for 7mm 2.5" drives both in the 1U and 2U form factor

Product Group: Echostreams Innovative Solutions | Evolutionizing Technology Behind IT Infrastructure
2U Server: Echostreams Innovative Solutions | Evolutionizing Technology Behind IT Infrastructure

 

[ATS]

Doesn't make sense. 2.5" HDD for servers tend to be 15mm to maximize capacity and for SSDs you have significantly higher internal volume in 15mm than in 2x 7/9mm. For SSDs, you can always use multiple stacked boards internally in the casing for more capacity. If you need more performance, you go NVMe which won't be a realistic bottleneck for quite some time (except for streaming workloads but those aren't generally performance constrained anyways). And with NVMe, you actually want to restrict the number of devices due to the PCIe lane issue and the cost of PCIe expanders (power, reliability, performance, price).

There are niche cases certainly where using 7mm drives might make sense, but that are rare. If you are buying enterprise drives, the cost differentials vs capacity are fairly linear.