Wednesday, December 7th 2022
Seagate Mechanical HDD with U.2 NVMe Interface Pictured, Signals the Decline of SAS 12G
Here's one of the first pictures of a mechanical HDD with NVMe interface. Seagate is apparently in production of an Exos-series Enterprise HDD featuring U.2 NVMe interface where one would expect SAS 12 Gbps. We seriously doubt if the HDD is fast enough to take advantage of U.2 NVMe (at least 32 Gbps per direction), but the move to NVMe probably has to do with the decline of older interface standards such as SAS 12 Gbps and SATA 6 Gbps in the enterprise space for cold-storage, and that future generations of rackmount DAS and NAS enclosures could increasingly feature U.2 backplanes, phasing out SAS and SATA. This is like when optical drives switched over to SATA despite not needing the bandwidth SATA had to offer (optical discs barely move a few dozen MB/s, for which even ATA33 IDE was sufficient). We don't know how the Seagate Exos drive handles NVMe internally—whether there is a new native NVMe controller, or whether this is really just a SAS 12 Gbps drive with a PCIe-to-SAS bridge chip.
Source:
Harukaze5719 (Twitter)
32 Comments on Seagate Mechanical HDD with U.2 NVMe Interface Pictured, Signals the Decline of SAS 12G
I found a super deep dive article focused on HBM memory and they went right into what's stored in the drive caches, DRAM cache and HBM cache by testing in a bajillion ways and they found they cache the 'index' for lack of a better word, rather than files
NVME w/ DRAM of course use them as a write buffer, as the one exception
Then I never liked hybrid drives, so uh do you :)They’re talking about SSHDs, not drive cache :)
At least have fun with it; why not 1TB/8TB? I’d still never buy one, but at least it wouldn’t feel like tech from a decade ago.
This part is an argument, though: Having a 1TB/8TB SSHD is an advancement over your suggested 64GB/8TB. Sorry you misunderstood and you’re welcome ;)
primarily they cache the file tables as well to reduce the amount of seeking - knowing what to spin when, in advance helps a lot.
Then the read/write cache was a mystery as to how they balanced it, but a lot of what was discovered was more that recently written files stayed in there, moreso than reads.
Like your office documents and cached images were kept, but large files never were so games got little benefit
To be fair, I do like the hybrid drives. I'm fixing up a PC for an old fart who bought a 1TB QVO to torrent to with 4GB of ram in his PC and as you can imagine that went fantastically well, with a dozen ways to fix this setup and zero of them chosen - SSHD, a mech drive for D: , enough RAM for a cache, aaaanyyyythiiiiing