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Comment by csense | Hacker News Reader

From the headline, I would guess WD is putting a user accessible CPU in each of their disk drives, idea being that if you have a CPU living close to the drive, then e.g. map+reduce workloads can be more efficiently executed. Instead of going with ARM or Intel, I guess the CPU's are using some less famous architecture called RISC-V.

Then I read the article, and the article is so full of buzzwords and genericisms that after reading the whole thing, I don't know if this guess is correct.

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In order to move the reader head inside your drive and to communicate with the host CPU you need microprocessors in your hard driver, really tiny ones. Now, instead of paying ARM for licences to use them WD is using open source processors that don't come with fees besides what it takes to manufacture them.

This is the right answer...they already use ARM, they want a one-time-fee license instead of royalties. Trying to shave a little margin.

WD made it clear in there talk that this wasn't about saving on costs, but rather having control over the innovation in the data space.

I don't see any reason to doubt them. It's an incredible risk to switch their entire company over to a still-growing ISA. But being able to design and modify any particular core as they see fit without having to talk to lawyers or negotiate a new contract... that's an incredible power.

RISC-V is certainly more unencumbered, but there's always the ARM architecture license too. Pricey, but you can modify and build on a relatively more mature ISA

An architectural license doesn't give you free reign to extend the ISA, just to create your own implementation of the standard ISA.

Is this confirmed though?

Were they using ARM? ( Proberly, but may not be in everything they use ) Are they switching over from ARM? Or simply moving their inhouse controller to RISC-V?

The one time license fee were suppose to be a lot cheaper if you are shipping in billions of unit.

Because if they are switching from ARM, I think of it as ARM being lazy and not winning the battle they ought to win, purely from a business perspective.

See this: https://www.malwaretech.com/2015/04/hard-disk-firmware-hacki...

Not definitive for the whole product line, but at least evidence of one popular WD drive with a Marvell/ARM controller. Google "Western digital Marvell" for more...like https://www.prnewswire.com/news-releases/marvell-achieves-si... (over one billion WD units with Marvell/ARM chips on board)

Western Digital's SanDisk SSDs almost exclusively use Marvell controllers, too.

Tiny microprocessors are there in almost all devices supporting DMA since long time right? So what this RISC-V versions will bring new to the table?

> So what this RISC-V versions will bring new to the table?

Not much, except being open, so WD can produce them without paying anyone royalties.

But in that case there would not be much of a point in making such an announcement, right? From a user perspective, I do not care at all what ISA the microcontroller inside the HDD/SSD uses, if it is not user accessible.

Unless they pass the savings on to their customers, that is. And even then, I am not so sure. Shaving a couple of cents of the price of a disk drive does not seem like a big deal to me.

Their stockholders might care, though.

Depends on what you care about, I suppose. I find it interesting, because I am interested in low-power processors.

This move, if it works well for WD, could lead to more attention being paid to a more open competitor to ARM, which would provide some competition and put downward pressure on ARM pricing. That, in turn, could have some potentially interesting second-order effects.

But yeah, if you only care about consumer prices and visible features, this is probably pretty boring stuff.

Mmmmh, now that I think of it: Does WD have their own fabs, or do they buy their chips from other vendors.

And if it's the latter - would WD buying a couple of billion chips a year have any effect on prices?

And now that you mention it - a company like WD announcing they will use RISC-V in their disks means they are serious about this, which in turn might make it easier for other to consider RISC-V a serious option.

I am very excited about RISC-V in theory, but unless somebody builds a "Raspberry-V", so to speak, it will probably be a long time before I get to play with one of these. I also think a high-performance implementation of RISC-V could make for an attractive component of a desktop machine / workstation. The Talos Raptor / II seems to be a sweet machine, but it is totally outside my budget. A less-high-end machine built around a RISC-V might change the equation.

> Western Digital plans to transition future core, processor, and controller development to the RISC-V architecture. The company currently consumes over one billion processor cores on an annual basis across its product portfolio. The transition will occur gradually and once completely transitioned, Western Digital expects to be shipping two billion RISC-V cores annually

I think that paragraph captures pretty well what they are doing; basically swapping out their current (proprietary) cores for RISC-V cores. I don't see any indication that the processors would be any more user accessible than current controllers. Considering the numbers presented, simply doubling the number of cores seems fairly conservative estimate, they will probably do that without any major paradigm shifts.

That said, it's not like they're user inaccessible either.

http://spritesmods.com/?art=hddhack

To be fair, it is strange that they broke out core, processor, and controller as separate items in that verbiage. They're probably referring to the application processors in My Cloud, external drives, and so on.

It doesn't seem so. I think they're just switching the internal processors that do LBA translation, error correction, bad-block marking etc over to RISC. And then their marketing department took that decision and ran with it in a completely different direction.

The key line is "... transitioning its own consumption of processors – over one billion cores per year – to RISC-V."

...which is a message to investors meaning "we're dropping the cost of our product without dropping prices".

If that ARM license is half a dollar, a billion devices per year is a lot of profit.

Your point still stands, but it’s probaably less than fifty cents unless they’re building something really high end.

Oldie but goodie: https://www.anandtech.com/show/7112/the-arm-diaries-part-1-h...

It would be surprising if prices didn't continue to drop.

Far more likely is that the SSD controllers that WD-SanDisk will create (that are the value-add difference between commodity NAND and good SSDs) will now use RISC-V cores. Samsung has a 5-core controller in its drives; I would guess that licensing costs are a pretty hefty chunk of the BOM for creating the controller

>> Samsung has a 5-core controller in its drives

Samsung is developing their own RISC-V cores too...

Hard drives already have moderately powerful processors in them. So there's no reason to assume any change in feature set.

> I would guess WD is putting a user accessible CPU in each of their disk drives, idea being that if you have a CPU living close to the drive, then e.g. map+reduce workloads can be more efficiently executed.

I don't see how this would be better than our current systems architecture. Is the interconnect between the disk drive and the main CPU/memory really the bottleneck?

Even if the CPU lives inside the disk drive case, it would still be limited by the same read/write speeds as a CPU 20cm away.

I was wondering, why they launched a huge recruitment campaign in Shenzhen for IC developers recently. I never saw them being big at chipmaking.

Now things got clear, they were hiring staff for that.

Their drives already have ARM chips on them for the controller. Presumably, they're just going to swap that out for RISC-V, with few (if any) user visible changes.

That would mean that the bandwidth from the hard drive is a large bottleneck, which I have a hard time believing is true.

AFAIK Doing error correction on 4K blocks of data is fairly non-trivial. Using custom instructions may be a benefit here too.

https://www.seagate.com/tech-insights/advanced-format-4k-sec...

The parent post was talking about user accessible CPUs for running instructions closer to the data on the hard drive. Error correction being trivial or not, I don't think that is user facing software.

If RISC-V turns out a competitor to ARM based Raspberry PI than it would be great.

If this initiative turns out to be a smart hard disk (HDD) that runs yet another full CPU with Minix like the infamous Intel ME gate. Then we don't need it, the world needs not another spy device, aka insecure hardware that has full acccess, yet is invisible to the users (= owner) of the device.

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