The connectors are rated for 1.5A per pin and have 3 pins for 12V, so these drives are pulling less than half of the connector's limit. Heat dissipation is a bigger challenge for U.2 than power delivery. (M.2 makes power delivery difficult because it only supplies 3.3V, and supplying 2.5+A of that with less than 5% voltage drop often requires putting the voltage regulators pretty close to the slots.)
system temp (from up to 25W for several devices, and that's on pcie3 nowadays) on connectors should stay (far) below 185F (85C) for guaranteed endurance of connecting contact resistance below 15mR, AFAIK
Somewhat unrelated rant: The m.2 standard sucks and we need to go back to 2.5”/3.5” drives. This can be done without sacrificing speeds. There was a demonstration recently that showed PCIE 4 speeds being maintained for 12 meters.
m.2 takes away from motherboard real estate on consumer devices, has limited real estate itself, and can be tricky to cool properly since you can only place a heatsink on one side of the drive.
Returning to a 2.5” form factor fixes all of these issues and as a bonus allows for a backplane to be plugged into an x32 or x16 slot to easily allow drive hotswap.
Wow, with the depth of those drive caddies and the weird single tiny connector, it looks like they might be using a backplane that could also be used in a 1U "ruler"/EDSFF style enclosure.
That's what it looks like to me, but WD didn't want to comment on that during our briefing. An EDSFF style backplane should be good for airflow whether or not it matches any of the standard EDSFF form factors. (Looks closest to the 2U 3" Long 16.8mm thick variant, which certainly isn't going to be the most popular EDSFF form factor for SSDs.)
Edit: Really bummed out about it using PCIe 3.0 though...No way I'm dropping ~$1000 on a ultra parallel 8tb or 16tb SSD that's still on 3.0. I imagine that many chips in parallel could be pushing 7-8gb/sec if not more.
one will have higher bandwidth and iops, even pcie4 on then 16 lanes, but probably (on consumer desktop mainboard) not that much capacity for that price like on above u.2 ssds https://www.micron.com/products/advanced-solutions... (q2/q3 2020?) is at 9GB/s read/write
and more desktop/workstation like Sabrent Rocket (~$199), Gigabyte Aorus and Corsair MP600 (pcie4 x4 lanes, 1TB, 1800TBW on 5yrs warranty (Sabrent) ~ 1 DWPD) are at 5-4.95GB/s reading and 4.4-4.25GB/s writing, with 750-600k random iops through m.2 connector
Um yeah, Sabrent Rocket... nice product (I just bought one), shame about the shoddy website experience you have to go through to register it for that 5 year warranty. Totally lets the product down.
That website didn't work with my modern browser (Pale Moon), refusing to list the registration I'd just made, and was programmed so badly I managed to register the same product twice without any complaint that it was already in the database. What sort of idiots are people hiring to code their main shopfronts these days? :( I'd be less bummed about all that if the support ticket I opened to find out what had happened to my registration hadn't been closed without any explanation, and they are not replying to my emails about all this.
I hope they provide better tech support for their products than they do for their website, because that's not fit for purpose ad has killed my confidence in their brand.
You could have gone with AORUS NVMe Gen4 SSD 2TB for about $400 also, with theoretically being able getting to warranty limits by 24h*10d full speed sequential writing to disk for to reach 3600TBW (what still is 1 DWPD), Sabrent also has 2TB pcie4 nvme and even SB-RKTQ-8TB on slower pcie3 (~$1800-$1999, 4TB ~$720) and another one, Seagate Firecuda 520 2TB at 5r/4.4wrGB/s level (but 2800TBW). Corsair MP600 also a 2TB on ~$400, but some complaints with overheating while on mainboard heatsink? And also no experience with TB3 and external nvme compared to this from my side, but might be comparable to pcie3 connected from theory.
While more exactly Sabrents 8TB is pcie3.1, its hard to tell where Intels Optane Alder Stream line fits into pcie4 nvme ssds, with advanced power and wear leveling management, https://wccftech.com/intel-next-generation-optane-... (table with comparing layers for 3D flash). Only Sabrent mentioning onfi4.0 support, while Gigabyte lists 2GB external DDR4. Another interesting point was that ~2026/2027 transition from hdd to flash ssd storage on servers could be done by a 90% level (https://wccftech.com/intel-next-generation-optane-... with hint to onfi4.1 with 400MT/s on page 12).
Possibly a silly question: Most modern SATA SSDs are bumping up against the 500MB/s bulk transfer limit. Could a SATA 2.5" SSD have two sata ports and be able to double data transfer that way? It could present itself to the system as a RAID0 striped array of some sort. That means the OS would understand it as being "two" SATA disks (of 0.5 size each) joined into a "single" fast volume. The OS would be able to deal with sending read and write requests through each SATA port as appropriate, just like when dealing with real dual disk RAID0.
Of course, the time for this is probably long past, with the rise of m.2 NVME, but it's an interesting thought.
Especially if I was buying a 4TB or 8TB+ 2.5" SSD, I'd be interested in dual port SATA operation, and the extra cost would only be a finger or two on top of the arm+leg they cost.
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ballsystemlord - Wednesday, June 24, 2020 - link
So what is the limit on the amount of power drives can pull over the SATA HDD connector?I mean, how much more could future models draw?
Billy Tallis - Wednesday, June 24, 2020 - link
The connectors are rated for 1.5A per pin and have 3 pins for 12V, so these drives are pulling less than half of the connector's limit. Heat dissipation is a bigger challenge for U.2 than power delivery. (M.2 makes power delivery difficult because it only supplies 3.3V, and supplying 2.5+A of that with less than 5% voltage drop often requires putting the voltage regulators pretty close to the slots.)back2future - Wednesday, June 24, 2020 - link
system temp (from up to 25W for several devices, and that's on pcie3 nowadays) on connectors should stay (far) below 185F (85C) for guaranteed endurance of connecting contact resistance below 15mR, AFAIKback2future - Thursday, June 25, 2020 - link
sorry, means could add upto additional 15mR (to connection resistance on a 30mR level for each pin)eek2121 - Tuesday, June 30, 2020 - link
Somewhat unrelated rant: The m.2 standard sucks and we need to go back to 2.5”/3.5” drives. This can be done without sacrificing speeds. There was a demonstration recently that showed PCIE 4 speeds being maintained for 12 meters.m.2 takes away from motherboard real estate on consumer devices, has limited real estate itself, and can be tricky to cool properly since you can only place a heatsink on one side of the drive.
Returning to a 2.5” form factor fixes all of these issues and as a bonus allows for a backplane to be plugged into an x32 or x16 slot to easily allow drive hotswap.
James5mith - Wednesday, June 24, 2020 - link
Wow, with the depth of those drive caddies and the weird single tiny connector, it looks like they might be using a backplane that could also be used in a 1U "ruler"/EDSFF style enclosure.Billy Tallis - Wednesday, June 24, 2020 - link
That's what it looks like to me, but WD didn't want to comment on that during our briefing. An EDSFF style backplane should be good for airflow whether or not it matches any of the standard EDSFF form factors. (Looks closest to the 2U 3" Long 16.8mm thick variant, which certainly isn't going to be the most popular EDSFF form factor for SSDs.)ksec - Wednesday, June 24, 2020 - link
Very interested in the SN340 as HDD replacement. I wonder how much would it cost.Santoval - Wednesday, June 24, 2020 - link
Do you have a motherboard with a U.2 slot? First start with that..Kakti - Thursday, June 25, 2020 - link
Just have to buy a PCIe to U.2 adapter card. $30 on Amazon, only requires x4 slotKakti - Thursday, June 25, 2020 - link
Edit: Really bummed out about it using PCIe 3.0 though...No way I'm dropping ~$1000 on a ultra parallel 8tb or 16tb SSD that's still on 3.0. I imagine that many chips in parallel could be pushing 7-8gb/sec if not more.back2future - Thursday, June 25, 2020 - link
one will have higher bandwidth and iops, even pcie4 on then 16 lanes, but probably (on consumer desktop mainboard) not that much capacity for that price like on above u.2 ssdshttps://www.micron.com/products/advanced-solutions... (q2/q3 2020?) is at 9GB/s read/write
back2future - Thursday, June 25, 2020 - link
and more desktop/workstation like Sabrent Rocket (~$199), Gigabyte Aorus and Corsair MP600 (pcie4 x4 lanes, 1TB, 1800TBW on 5yrs warranty (Sabrent) ~ 1 DWPD) are at 5-4.95GB/s reading and 4.4-4.25GB/s writing, with 750-600k random iops through m.2 connectorasmian - Thursday, June 25, 2020 - link
Um yeah, Sabrent Rocket... nice product (I just bought one), shame about the shoddy website experience you have to go through to register it for that 5 year warranty. Totally lets the product down.That website didn't work with my modern browser (Pale Moon), refusing to list the registration I'd just made, and was programmed so badly I managed to register the same product twice without any complaint that it was already in the database. What sort of idiots are people hiring to code their main shopfronts these days? :( I'd be less bummed about all that if the support ticket I opened to find out what had happened to my registration hadn't been closed without any explanation, and they are not replying to my emails about all this.
I hope they provide better tech support for their products than they do for their website, because that's not fit for purpose ad has killed my confidence in their brand.
back2future - Thursday, June 25, 2020 - link
You could have gone with AORUS NVMe Gen4 SSD 2TB for about $400 also, with theoretically being able getting to warranty limits by 24h*10d full speed sequential writing to disk for to reach 3600TBW (what still is 1 DWPD), Sabrent also has 2TB pcie4 nvme and even SB-RKTQ-8TB on slower pcie3 (~$1800-$1999, 4TB ~$720) and another one, Seagate Firecuda 520 2TB at 5r/4.4wrGB/s level (but 2800TBW). Corsair MP600 also a 2TB on ~$400, but some complaints with overheating while on mainboard heatsink? And also no experience with TB3 and external nvme compared to this from my side, but might be comparable to pcie3 connected from theory.back2future - Thursday, June 25, 2020 - link
While more exactly Sabrents 8TB is pcie3.1, its hard to tell where Intels Optane Alder Stream line fits into pcie4 nvme ssds, with advanced power and wear leveling management, https://wccftech.com/intel-next-generation-optane-... (table with comparing layers for 3D flash). Only Sabrent mentioning onfi4.0 support, while Gigabyte lists 2GB external DDR4. Another interesting point was that ~2026/2027 transition from hdd to flash ssd storage on servers could be done by a 90% level (https://wccftech.com/intel-next-generation-optane-... with hint to onfi4.1 with 400MT/s on page 12).back2future - Thursday, June 25, 2020 - link
Multiplexing can lift capabilities for nand data rates to 2020 spec onfi4.2 at 1600MT/s top level with onfi4.1 components used only (https://www.idt.com/us/en/about/press-room/idt-int...back2future - Thursday, June 25, 2020 - link
edit: https://www.flashmemorysummit.com/English/Collater...back2future - Thursday, June 25, 2020 - link
with OCuLink gen4 x16 16GT/s (SFF-8611) http://cdn.teledynelecroy.com/files/manuals/pciege... Thunderbolt 3 can be an alternativeTomatotech - Friday, July 3, 2020 - link
Possibly a silly question: Most modern SATA SSDs are bumping up against the 500MB/s bulk transfer limit. Could a SATA 2.5" SSD have two sata ports and be able to double data transfer that way? It could present itself to the system as a RAID0 striped array of some sort. That means the OS would understand it as being "two" SATA disks (of 0.5 size each) joined into a "single" fast volume. The OS would be able to deal with sending read and write requests through each SATA port as appropriate, just like when dealing with real dual disk RAID0.Of course, the time for this is probably long past, with the rise of m.2 NVME, but it's an interesting thought.
Tomatotech - Friday, July 3, 2020 - link
Especially if I was buying a 4TB or 8TB+ 2.5" SSD, I'd be interested in dual port SATA operation, and the extra cost would only be a finger or two on top of the arm+leg they cost.