SSHD RAID 0 write and read speeds

[CryWolf]

Hello all,

 

I just realized in the last 3 days that my SSHD RAID 0 reads and writes might not be as fast as it should. I'm using 2 SSHD from Seagate (model ST2000DX001) in RAID 0 with write-back cache. Around the internet, and from the manufactor manual, you can find that its read and write average are 156MB/s but mine, even in RAID 0, are not getting these speeds.

 

Seagate Product Manual: https://www.seagate.com/files/www-content/product-content/sshd-fam/desktop-sshd/en-us/docs/100726566m.pdf

 

My motherboard is an ASUS ROG STRIX x99 GAMING with 8 SATA 6Gb/s ports. 

https://www.asus.com/Motherboards/ROG-STRIX-X99-GAMING/specifications/

 

I don't understand much about SSHD and RAID 0 performance but my felling is that my SSHDs are not working as they should. I will attach some benchmarks from my RAID 0 so you guys can tell me if everything is working fine or I should ask for Seagate warranty to replace them.

 

Thank you

 

[Braegnok]

SSHD RAID-0 is limited to the spindle speed & density of the platters, so no impressive speed will be found vs a "pure" SSD RAID-0,.. if you are pulling large data files off the SSHD's the cache is moot as a new write going to the cache also goes to the HDD, and when the HDD gets bottlenecked with writes, the SSD will set and wait for HDD to finnish. 

[Fight Game]

should still be better than that.  make sure there is absolutely nothing else going on while the test is going

[Fight Game]

try a benchmark that shows cpu% during the test

[CryWolf]

SSHD RAID-0 is limited to the spindle speed & density of the platters, so no impressive speed will be found vs a "pure" SSD RAID-0,.. if you are pulling large data files off the SSHD's the cache is moot as a new write going to the cache also goes to the HDD, and when the HDD gets bottlenecked with writes, the SSD will set and wait for HDD to finnish. 

I understand but shouldn't the RAID 0 from 2 SSHDs that should have, by itself, 150MB/s read and writes speeds, perform around 300mb/s read and write?

 

should still be better than that.  make sure there is absolutely nothing else going on while the test is going

I have some programs and page files on it, but nothing is running.

 

try a benchmark that shows cpu% during the test

Here are 2 more benchmarks I could find >>>  https://www.imageupload.co.uk/image/4Z0V

Please let me know of others that I could try.

 

Look at the first image on the first post. The benchmarks show different results. DiskMark v1.0.0.8 shows great read and writes, around 300mb/s but AS SSD Benchmark v2.0.6694 and ATTO Disk Benchmark v4.00.0f2 shows around the same result, 280 for write speed and 170 for read speed. But the Crystal Disk Mark v6.0.1 shows very low speed. Why is that? Wich one is right?

 

On the new benchmarks we see this happening again. Anvil Benchmark v1.1.0 shows lower speeds and HD Tach v3.0.4.0 shows a great read.

 

I'm confused.

 

Sorry for the long time to reply, I can only post one time a day.

Edited June 27, 2018 by CryWolf

[Braegnok]

The Seagate SSHD use Adaptive Memory Technology where it effectively identifies the most frequently-used data and stores it in the NAND flash. This means that if you are using as an OS drive, or storage for your games and applications, you will definitely benefit from RAID-0 but you will not likely see double read and write speeds. As a result, you should be able to see improvements in terms of loading time vs single SSHD. However, there is an exemption. If you plan to use them to edit high definition videos or computer aided designs that use large and rapidly changing data sets, you will not see any significant benefits using SSHD in RAID-0.

 

This is why some of the benchmark tests showed promising results, as read/write speed almost doubled. However, they didn't perform well with Anvils Benchmark test, or Crystal Disk Mark test. This is due to the fact that its learning technology wasn't able to learn the pattern in time to speed things up. Nevertheless, those are still good numbers considering that your basically using HDDs with 8GB NAND, I would not worry about the benchmark results. 

 

If your looking for performance boost, just add a 120GB SSD for primary drive, and use the SSHD's for your storage. 

 

My daily driver PC is a Dell OptiPlex 7050 Micro mounted on the back of a 32" 4K Dell monitor, with Dell keyboard & mouse. It's a vary basic OEM PC with 3.0x2 M.2 interface. I upgraded to the new Intel Optane 800P 118GB M.2, & Intel 545s 512GB SSD for storage,.. with Windows 10 Pro 64-bit OS, and all my Applications, Microsoft Office loaded on C drive I barely use 40GB disk space, so 118GB works fine as my primary drive. 

 

 

Edited July 3, 2018 by Braegnok

[CryWolf]

The Seagate SSHD use Adaptive Memory Technology where it effectively identifies the most frequently-used data and stores it in the NAND flash. This means that if you are using as an OS drive, or storage for your games and applications, you will definitely benefit from RAID-0 but you will not likely see double read and write speeds. As a result, you should be able to see improvements in terms of loading time vs single SSHD. However, there is an exemption. If you plan to use them to edit high definition videos or computer aided designs that use large and rapidly changing data sets, you will not see any significant benefits using SSHD in RAID-0.

 

This is why some of the benchmark tests showed promising results, as read/write speed almost doubled. However, they didn't perform well with Anvils Benchmark test, or Crystal Disk Mark test. This is due to the fact that its learning technology wasn't able to learn the pattern in time to speed things up. Nevertheless, those are still good numbers considering that your basically using HDDs with 8GB NAND, I would not worry about the benchmark results. 

 

If your looking for performance boost, just add a 120GB SSD for primary drive, and use the SSHD's for your storage. 

 

My daily driver PC is a Dell OptiPlex 7060 Micro mounted on the back of a 32" 4K Dell monitor, with Dell keyboard & mouse. It's a vary basic OEM PC except for the drives. I upgraded to the new Intel Optane 800P 118GB M.2, & Intel 545s 512GB SSD for storage,.. with Windows 10 64-bit OS and all my Applications, Microsoft Office loaded on C drive I barely use 40GB disk space, so 118GB works fine as my primary drive. 

 

2018-06-29 (1).png

Wow, nice speeds you have there.

 

Just teach me one thing. Shouldn't RAID 0 improve 70% to 100% speeds from a single SSHD? Would it be better to use 2 normal HDD in RAID 0 than 2 SSHD em RAID 0? Wich one should have better performance?

 

I just bought a M.2 Samsung 970 EVO 2TB, it's gonna take some days to arrive but it will solve my problems. It was very expensive too so I wish it last some years lol.

 

Thank you for the help

[Braegnok]

Your not going to increase the spindle speed & density of the platters on a HDD by running RAID-0. The SSHD will show a slight performance boost loading what ever is stored in the 8GB NAND, but you will not see 70 to 100% increase. In RAID-0 you have 1/2 your data on one drive and 1/2 your data on the other, when transferring the data together each drive is only sending 1/2 the size of data compared to a single drive,.. sending a 50GB file, the RAID-0 drives are both sending 25GB each, so odds are the two drives together sending 25GB will complete the transfer quicker than a single drive sending 50GB data. 

 

I would strongly advise to not RAID-0 your SSHD's, but would use them as two separate storage drives, and use the new Samsung 970 as your primary,.. due to the high risk of loosing all your data if one drive fails, the risk out weighs slight performance gain with HDD's in RAID-0.

 

Enjoy your new drive, performance is nice but it's not cheep.        

[CryWolf]

Your not going to increase the spindle speed & density of the platters on a HDD by running RAID-0. The SSHD will show a slight performance boost loading what ever is stored in the 8GB NAND, but you will not see 70 to 100% increase. In RAID-0 you have 1/2 your data on one drive and 1/2 your data on the other, when transferring the data together each drive is only sending 1/2 the size of data compared to a single drive,.. sending a 50GB file, the RAID-0 drives are both sending 25GB each, so odds are the two drives together sending 25GB will complete the transfer quicker than a single drive sending 50GB data. 

 

I would strongly advise to not RAID-0 your SSHD's, but would use them as two separate storage drives, and use the new Samsung 970 as your primary,.. due to the high risk of loosing all your data if one drive fails, the risk out weighs slight performance gain with HDD's in RAID-0.

 

Enjoy your new drive, performance is nice but it's not cheep.        

Hummm. I thought that the speeds would double because of you just said "n RAID-0 you have 1/2 your data on one drive and 1/2 your data on the other, when transferring the data together each drive is only sending 1/2 the size of data compared to a single drive,.. sending a 50GB file, the RAID-0 drives are both sending 25GB each, so odds are the two drives together sending 25GB will complete the transfer quicker than a single drive sending 50GB data.". But got it. I will do as you say.

 

Thank you a lot for everything. I really appreciate your help

[ir_cow]

Does the NAND even work when Raided? Since the drive are stripped per block, no single file is on one drive. The NAND sees the most used "blocks" and places them in the NAND for quick access, but with it stripped in Raid-0 I wonder if the NANDs actually cause more problems since each drive has to determine what is used the most. Say one block in on a NAND while the other drive has it on the 3rd platter. Your computer is still waiting for the complete file and defeats the purpose of those 8GB NANDs and the extra cost.

[Braegnok]

There is a lot of waiting and fetching going on.   

Edited July 2, 2018 by Braegnok