The u.2 form factor is slightly larger than a 2.5" drive. I can imagine the entire space in it taken by Flash chips. I can't imagine what cooling scheme do they employ for the chips in the middle.
Apparently TDP is 30 watts¹, according to the product brief. I would imagine it's a single PCB with flash chips on both sides then thermally bonded to the aluminum chassis. That should keep all chips at approximately the same temperature. On its own it could be easily air cooled, but with 24 in a 2U chassis you'll be having some decently hefty forced air over the drives.
1. For comparison, an HDD usually comes in around ~10 watts
The transfer rates limit how much each chip can be active at any given time, so a heat-aware writing allocator can pick the least active blocks for the next writes and distribute the heat accordingly. Even if it’s not heat-aware, the tendency will be that the writes will be distributed over as many chips as there are, and so will be the heat generated.
Now, I would LOVE to see this much SLC flash on a direct to bus attachment setting.
Over the past few years the main improvement in SSD capacity has been due to them stacking an ever-increasing number of NAND layers in a single chip, with state-of-the-art SSDs already having over 300 layers.
No need to worry about cooling when each layer in the sandwich is only a fraction of a micrometer thick!
the u.2 form factor indeed evolved from chassis designs that were originally 2.5" drives. It's now kind of becoming obsolete with new designs using things like E1S, E1L (exactly the correct height to be slotted into a 1U server, it's like a slightly wider M.2, but meant to be insertable and removable), and E3S and E3L.
Note that the 245TB is an E3L, the half size version of it come in smaller size.
Can someone who knows explain what is the benefit of having all that data in one ssd instead of splitting it up into hundreds of individual drives? Does the single ssd benefit is more performance or does it really tuen out to be cheaper than hundreds of individual drives?
It’s about density in a datacenter. With this you have 1PB in 4 drives, fitting in a 1u rack, which is just incredible. Also these drives don’t use regular SATA or SAS, they use PCIe, so these drives are also quite fast in comparison. Density has a power efficiency aspect as well both in just having fewer drives and requiring fewer servers to put drives into.
You’re actually right, it’s just that datacenters like density and will gladly split your data onto hundreds of these little amazing magical bits of technology rather than hundreds of less magical ones in the same physical volume.
4-5x times what it would have been if not for the demand from AI. According to my rough calculation 4-8tb ssd drives were going to reach parity with hdd this year
> What accounts for the premium price/TB of these extremely high capacity enterprise-targeted drives?
Spare capacity, mostly. That’s why they have higher endurance. If you want to double the endurance of a given drive, tell the controller to allocate twice as many spare blocks and report less capacity than you would otherwise.
In this case, you are also paying a premium for the PCIe attachment instead of SAS, and a lot for price elasticity. You see, with drives like these you slash space and energy consumption in relation to HDDs by a large number, and that allows you to pay a premium for the device, because, at the end of its lifetime, it’ll have more than covered the cost difference in saved space and energy.
The datasheet shows 3GB/s sequential write, which for 245.76TB means writing the whole drive takes around 22h45m. Odd that the endurance is specified as "1.0 SDWPD", which is almost meaningless since the drive takes roughly that long to write at full speed.
At scale, 1.9 times more energy is required for an HDD deployment
...but those HDDs are going to hold data for far more than twice as long. It's especially infuriating to see such secrecy and vagueness around the real endurance/retention characteristics for SSDs as expensive as these.
On the other hand, 60TB of SLC for the same price would probably be a great deal.
Perhaps their usual buyers just care less about retention?
Those drives aren't going to be used for cold storage, and it is basically a guarantee that there will be checksums and some form of redundancy. Who cares whether the data is retained for 10 or for 15 years after writing when you can do a low-priority background scrub of the entire drive once a month, and when there are already mechanisms in place to account for full-drive failure?
1. For comparison, an HDD usually comes in around ~10 watts
Now, I would LOVE to see this much SLC flash on a direct to bus attachment setting.
No need to worry about cooling when each layer in the sandwich is only a fraction of a micrometer thick!
Note that the 245TB is an E3L, the half size version of it come in smaller size.
https://americas.kioxia.com/en-ca/business/ssd/solution/edsf...
https://www.exxactcorp.com/blog/storage/edsff-e1s-e1l-e3s-e3...
https://www.simms.co.uk/tech-talk/e1s-e1l-the-new-server-for...
You don't have permission to access
"http://investors.micron.com/news-releases/news-release-detai..." on this server.
High security on this press release.
So it's not exactly about cost savings, but having the option to do more, faster.
Also, you could also get much higher bandwidth density out of this vs HDD, and this is great for AI training
I haven't bought a hard drive or an SSD in at least a decade (I get stuff for free, basically) but…that seems a bit high, right?
Seems like well-rated consumer-level SSDs cost around $250 for 1TB right now.
What accounts for the premium price/TB of these extremely high capacity enterprise-targeted drives?
Spare capacity, mostly. That’s why they have higher endurance. If you want to double the endurance of a given drive, tell the controller to allocate twice as many spare blocks and report less capacity than you would otherwise.
In this case, you are also paying a premium for the PCIe attachment instead of SAS, and a lot for price elasticity. You see, with drives like these you slash space and energy consumption in relation to HDDs by a large number, and that allows you to pay a premium for the device, because, at the end of its lifetime, it’ll have more than covered the cost difference in saved space and energy.
The word "enterprise".
The datasheet shows 3GB/s sequential write, which for 245.76TB means writing the whole drive takes around 22h45m. Odd that the endurance is specified as "1.0 SDWPD", which is almost meaningless since the drive takes roughly that long to write at full speed.
At scale, 1.9 times more energy is required for an HDD deployment
...but those HDDs are going to hold data for far more than twice as long. It's especially infuriating to see such secrecy and vagueness around the real endurance/retention characteristics for SSDs as expensive as these.
On the other hand, 60TB of SLC for the same price would probably be a great deal.
Those drives aren't going to be used for cold storage, and it is basically a guarantee that there will be checksums and some form of redundancy. Who cares whether the data is retained for 10 or for 15 years after writing when you can do a low-priority background scrub of the entire drive once a month, and when there are already mechanisms in place to account for full-drive failure?