Do you think consumer SSHDs should have more than 8GB NAND?

[cbn]

Do you think consumer SSHDs should have more than 8GB NAND?

(You can vote up to three times. I did this so a person can vote once for each of the categories....3.5", 2.5" and U.2*)

*U.2 for hard drives, of course, doesn't exist yet. The closest we have got (so far) was the following:

P.S. Another option for U.2 SSHD could have been NAND. It would take a good amount of it though (depending on the quality of NAND) to saturate read on PCIe 3.0 x 4. Then as the PCIe spec increases in the future (PCIe 4.0, 5.0 etc) the amount of NAND needed to saturate would only further increase.

 

[cbn]

I think 64GB NAND on a 4TB 3.5" HDD makes sense.....and it could even be used as a boot drive with most "older" desktop computers these days. (Some people don't like to manage different drives and want a single large volume instead).

This way even if the hard drive is mostly filled up (the only free space on the platter is near the spindle).....a newly installed app or program can still be read at fast speed if it ends up being frequently used.

P.S. An alternative to a 4TB+ SSHD would be 2 x 2TB+ 3.5" HDDs in RAID-0. This set-up would also allow faster speeds (than a single 4TB+ 3.5" HDD) for frequently apps/programs installed near the spindle. In fact, sometimes these smaller capacity 3.5" drives also have a faster rotational speed compared to single 4+ TB HDD or 4+ TB SSHD.(Example: The 2TB Seagate Barracuda Compute is 7200rpm, but the 4TB Barracuda Compute is 5900rpm. The more expensive 4TB Seagate Barracuda Pro, however, is 7200 rpm). Of course, reliability would be less (than a single HDD or SSHD) and the desktop machine also needs a chipset supporting RAID.

 

[Ancalagon44]

When you look at the pricing, SSHDs make no sense at all. For the price of one SSHD, you could get a larger SSD and the same sized HDD.

Yes, they are integrated and that is pretty cool, but way too expensive for the amount of SSD cache they have. They would need to have far more SSD cache while costing exactly the same, which we all know won't happen. If they added extra SSD space, they would increase the cost dramatically.

 

[cbn]

Yes, they are integrated and that is pretty cool, but way too expensive for the amount of SSD cache they have. They would need to have far more SSD cache while costing exactly the same, which we all know won't happen. If they added extra SSD space, they would increase the cost dramatically.

When you wrote "extra SSD space" do you mean extra room on the PCB for NAND?

If that is what you meant.....I don't think they would do that. Instead, they would just increase the number of NAND dies in the package and/or use die(s) with a larger capacity.

 

[Ancalagon44]

When you wrote "extra SSD space" do you mean extra room on the PCB for NAND?

If that is what you meant.....I don't think they would do that. Instead, they would just increase the number of NAND dies in the package and/or use die(s) with a larger capacity.

How they implement it is up to them - larger dies or an increased number of die, the choice is up to them. However, for cost reasons, I doubt it will happen. If there was a cost effective way of having a 64GB SSD storage area combined with a 1TB HDD, they would have already done so.

As it is, for whatever reason, they are so expensive that I imagine most consumers would rather just buy a HDD or an SSD, not a hybrid. Hybrids offer the worst of both worlds - the high cost per GB of an SSD coupled with the relatively slow access speed of an HDD.

They should rather look at alternative ways of speeding up HDDs. Something like a much larger DRAM cache coupled with enough capacitors to protect against sudden power loss. Something like 1GB of DRAM, so that writes will be fast (unless you write over 1GB at a time). Not really that much that they can do about seek times or read speed.

 

[cbn]

Something like 1GB of DRAM, so that writes will be fast (unless you write over 1GB at a time).

More DRAM would be nice.

Also, what about on a 3DXpoint SSHD using a portion of it for buffering writes to the platter? In contrast to NAND, 3DXpoint is a lot tougher and has lower latency. With this mentioned, I do wonder how a 64GB NAND SSHD would work with ~750MB pseudo SLC as a cache for writes to the platter*? Normally the NAND on a SSHD is only used for reads as described below:

http://www.anandtech.com/show/3734/seagates-momentus-xt-review-finally-a-good-hybrid-hdd

The size of the NAND was a shocker to me when I first heard it. I honestly expected something much larger. In the Momentus XT however, the SLC NAND acts exclusively as a read cache - writes never touch the NAND. The drive looks at access patterns over time (most likely via a history table of LBAs and their frequency of access) and pulls some data into the NAND. If a read request comes in for an LBA that is present in the NAND, it's serviced out of the 4GB chip. If the LBA isn't present in the NAND, the data comes from the platters.

*One concern I would have would be write consistency as I would expect all the NAND to be completely filled with DATA on a SSHD. Greater over provisioning (thus smaller than 64GB capacity for Read cache) + use pseudo SLC cache (for writes to platter) vs. using the all 64GB NAND as a Read cache only?

 

[cbn]

When you look at the pricing, SSHDs make no sense at all. For the price of one SSHD, you could get a larger SSD and the same sized HDD.

Here is the Current Pricing for 3.5" 2TB Barracuda and 3.5" 2TB Firecuda:

https://www.newegg.com/Product/Prod...0446076&PID=3821802&SID=j8g9e304fp01045l00053 ($66.99 FS)

https://www.newegg.com/Product/Prod...2178996&cm_re=firecuda-_-22-178-996-_-Product ($99.99 FS)

So yes, a $32 difference.....but I did notice the Firecuda has a 5 year warranty vs. a 2 year warranty on the Barracuda.

P.S. The older model (ST1000LX001) 2.5" 1 TB SSHD with 32GB NAND also had 5 year warranty---> https://www.cnet.com/products/seagate-laptop-sshd-st1000lx001-hybrid-hard-drive-1-tb-sata-6gb-s/specs (Interesting to see Non-Recoverable Errors @1 per 10^15, this is enterprise level. Normally I see Non-Recoverable Errors @1 per 10^14 for consumer HDD and SSHD. Example:The 1TB and 2TB 3.5" Firecuda lists Non-Recoverable Errors @1 per 10^14.....and so do the 2.5" Firecuda SSHDs)

EDIT: I noticed the Barracuda Pro 3.5" HDD has Non-Recoverable Errors @1 per 10^15, even the 2TB model.

 

[Elixer]

I wouldn't bother with SSHDs at all. If that NAND dies out, can you still use the HD?
I also wonder about GC on such a small amount of NAND.

 

[cbn]

Here are prices on the 2TB 2.5" Firecuda on Newegg and Amazon:

https://www.newegg.com/Product/Product.aspx?Item=N82E16822179110 ($89.99 plus $4.99 shipping)

https://www.amazon.com/gp/product/B01M1NHCZT ($89.99 free shipping)

......compared to the 2TB 2.5" Barracuda (which is the same SMR platter drive, but without the NAND and longer warranty of the Firecuda) on Newegg and Amazon.

https://www.newegg.com/Product/Product.aspx?Item=N82E16822179107&ignorebbr=1 ($84.99 free shipping)

https://www.amazon.com/Seagate-BarraCuda-2-5-Inch-Internal-ST2000LM015/dp/B01LX13P71 ($84.99 free shipping)

So in 2.5" there is only $5 or $10 increase in price for the extra 8GB NAND and 3 year longer warranty (5 year for Firecuda vs. 2 year warranty for Barracuda).

P.S. These are only 7mm thick, but laptops and PS4/PS4 Pro can take 9.5mm thick 2.5" drives.

 

[cbn]

They should rather look at alternative ways of speeding up HDDs. Something like a much larger DRAM cache coupled with enough capacitors to protect against sudden power loss.

Or how about bundling some cache software? (I'm thinking about software that could use part of the system RAM as a write cache. This particularly for laptops which suffer from slower writes due to the 2.5" platters....but benefit from having a battery which acts as a UPS.)

P.S. Looking at post #9, the 2.5" 2TB Firecuda at Amazon is now $79.99 FS. (Interesting that is now cheaper than the equivalent drive without NAND and a shorter warranty)

 

[Ancalagon44]

Or how about bundling some cache software? (I'm thinking about software that could use part of the system RAM as a write cache. This particularly for laptops which suffer from slower writes due to the 2.5" platters....but benefit from having a battery which acts as a UPS.)

P.S. Looking at post #9, the 2.5" 2TB Firecuda at Amazon is now $79.99 FS. (Interesting that is now cheaper than the equivalent drive without NAND and a shorter warranty)

I personally would never go for a software cache solution like that. Most people, including myself, don't like to install software that hardware manufacturers provide with the exception of drivers. I don't want Western Digital's bloatware on my computer for example.

Right now I'm actually wondering what the point is of SSHDs. If you think about it, the problem with them is that the user does not necessarily know how much of his data is in the fast read section. It doesn't give you determinism. I mean, with a separate SSD and HDD, I know what to expect performance wise. With an SSHD? Who knows? Could I be guaranteed that all of the files for my favourite game are on the SSD portion? What if most of the levels load quickly and then suddenly one of them bombs?

The downside of course is that separate drives must be administered manually and that means a user who knows what he is doing.