Question Speed difference between modern 2.5 and 3.5 HDD

[Staples]

I do a fair amount of media editing which requires a lot of writing to the disk. Currently I have all SSDs but worry about the wear of the drives. I'd like to purchase a HDD to cut down on temporary writes to the SSD drives. I'd like a 2.5" drive because they would better fit my mITX case but I wonder what the speed difference between the two form factors. If you search for this question, there are sites that claim that 2.5" drives are slower but I am unable to find actual numbers anywhere. If we are talking 10% slower, than I don't care. If we are talking 50% slower, then I will figure out a solution to make a 3.5" drive work.

 

[razel]

The difference will be that 3.5" you'll be interested in will be 7200RPM while 7200RPM is non-existent in 2.5". I would not worry about writes with SSDs. They are not expensive these days. Intel 660p NVME 1TB got as low as $87 earlier this year and it's 5 year warranty for rated daily writes will be beyond your need I'm sure. Even if it isn't, it was only $87.

 

[Staples]

I agree that SSDs are not too expensive unless you are trying to get a high capacity one. I have one of those Intel 660p TB drives you speak of. But when you fill up disks and have 200GB free then repeatedly copy over 128GB SD cards, you put a lot of wear on the drive because you are constantly writing to the same cells. So I do think there is still a case for HDD for second drives in systems. I realize there is a 5 year warranty but I've had SSDs go bad and when they do, nothing works and you lose everything. I guess speed isn't my main concern anymore, reliability is part of the equation. When sectors on HDD go bad, you can usually still recover most of the data.

 

[mxnerd]

With 2.5" 5400rpm HDD, you will need put 2 drives in RAID 0 to achieve over 200MB/s . A single 6TB 7200rpm 3.5" HDD can put the speed at 220MB/s

 

[killster1]

I do a fair amount of media editing which requires a lot of writing to the disk. Currently I have all SSDs but worry about the wear of the drives. I'd like to purchase a HDD to cut down on temporary writes to the SSD drives. I'd like a 2.5" drive because they would better fit my mITX case but I wonder what the speed difference between the two form factors. If you search for this question, there are sites that claim that 2.5" drives are slower but I am unable to find actual numbers anywhere. If we are talking 10% slower, than I don't care. If we are talking 50% slower, then I will figure out a solution to make a 3.5" drive work.

just use a external 2x8tb. the reason for using a hdd is that when it fails it might be recoverable seems funny to me, just copy it over twice to the 2x8tb if its important at all and have it on all 3 drives!

 

[VirtualLarry]

the reason for using a hdd is that when it fails it might be recoverable seems funny to me

Around here, we call that bass-ackwards reasoning.

Backups!

 

[Jeff7181]

So, the problem with your question is that the size of the disk isn't directly related to the speed of the disk. A 5.4k RPM 2.5" HDD will almost certainly be slower than a 7.2k RPM 3.5" HDD. But a 10k RPM 2.5" HDD will almost certainly be faster than a 7.2k RPM 3.5" HDD.

Also, "fast" depends on your workload. I'm guessing your workload will be largely sequential as opposed to random IO so you may not even notice the difference between a 7.2k HDD and a 10k HDD. However, for those times when you have a random IO workload, you'll notice the difference.

However, if you're that worried about it, rather than shuffling your working set around between disk types, and instead of buying spinning disks with the goal of increasing reliability, you'd probably be better serviced by investing in another SSD with higher TBW, such as the Patriot Viper VPR100.

 

[thesmokingman]

I can't imagine that a single user could wear an ssd down in a single lifetime.

 

[mxnerd]

Scheduled backup or files syncing is absolutely necessary if the data is valuable since SSD really can go kaput anytime.

 

[Staples]

I can't imagine that a single user could wear an ssd down in a single lifetime.

Unless I am misunderstanding something, the estimated life of write cycles on this 1TB Samsung EVO 860 drive I have is 600. If you write 600TB to the drive (and that is assuming it is fully emptied before each write which is unrealistic), then the drive has reached the minimum estimated life. 600 write cycles is one of the better numbers you will see. If you buy a 256GB drive with estimated write cycles of 200, then you can burn through the estimated life really quickly. I do not think the number of writes to a HDD equates to wearing down the lifespan of the device.

I imagine the drives could last far longer than their estimated life cycle but as I've stated before, I've managed to kill two in my lifetime so far.

 

[mikeymikec]

I don't think I've ever seen a 2.5" HDD get past 100MB/sec. A decent modern 3.5" HDD tends to do 150-200MB/sec at best.

Also bear in mind that a HDD won't give you uniform performance right across its entire capacity. Some areas of the drive platters can be interacted with faster than others. So you might see a decent 3.5" HDD sometimes do 100MB/sec, just as you might see a 2.5" HDD do say 50-60MB/sec.

Scheduled backup or files syncing is absolutely necessary if the data is valuable since SSD really can go kaput anytime.

And in my experience, when an SSD goes faulty, you're lucky if it doesn't go completely titsup at a moment's notice.

 

[mxnerd]

I don't think I've ever seen a 2.5" HDD get past 100MB/sec.

All the numbers are sequential, not random.

==

My Transcend 2TB 5400RPM USB 3.1 drive. So if you put 2 of them in RAID 0, then you get over 200MB/s




==

My 2 x 500GB Seagate 7200RPM in RAID 0

As @razel has said, you can't find 7200rpm 2.5" drives anymore.



==

6TB 3.5" 7200RPM drive

Seagate Ironwolf 6TB NAS Hard Drive Review

Today we're reviewing an item that has gotten very little love on the site, something we all have and use but frankly take for granted all the time. The hard drive has been somewhat forgotten as most people mention how its an out of date technology and that NAND is the future, well that still...

wccftech.com

 

[Insert_Nickname]

I do a fair amount of media editing which requires a lot of writing to the disk. Currently I have all SSDs but worry about the wear of the drives. I'd like to purchase a HDD to cut down on temporary writes to the SSD drives. I'd like a 2.5" drive because they would better fit my mITX case but I wonder what the speed difference between the two form factors. If you search for this question, there are sites that claim that 2.5" drives are slower but I am unable to find actual numbers anywhere. If we are talking 10% slower, than I don't care. If we are talking 50% slower, then I will figure out a solution to make a 3.5" drive work.

The difference will be that 3.5" you'll be interested in will be 7200RPM while 7200RPM is non-existent in 2.5".

There should still be 2.5" WD Black 7200RPM around. Just make sure to get the non-SMR version (WD10JPLX).

You won't find a better 2.5" HDD with better performance. They can do upwards of 140MB/s on the outer cylinders, and since they're 7200RPM with 2.5" platters, they're quite quick to access too.

I guess speed isn't my main concern anymore, reliability is part of the equation. When sectors on HDD go bad, you can usually still recover most of the data.

Scheduled backup or files syncing is absolutely necessary if the data is valuable since SSD really can go kaput anytime.

And in my experience, when an SSD goes faulty, you're lucky if it doesn't go completely titsup at a moment's notice.

This cannot be emphasised enough. Always backup.

Unless I am misunderstanding something, the estimated life of write cycles on this 1TB Samsung EVO 860 drive I have is 600. If you write 600TB to the drive (and that is assuming it is fully emptied before each write which is unrealistic), then the drive has reached the minimum estimated life. 600 write cycles is one of the better numbers you will see. If you buy a 256GB drive with estimated write cycles of 200, then you can burn through the estimated life really quickly. I do not think the number of writes to a HDD equates to wearing down the lifespan of the device.

I imagine the drives could last far longer than their estimated life cycle but as I've stated before, I've managed to kill two in my lifetime so far.

If you do a lot of writes, keep an eye on drive temperatures. That's usually what kill them.

 

[piokos]

If we are talking 10% slower, than I don't care. If we are talking 50% slower, then I will figure out a solution to make a 3.5" drive work.

Definitely a larger gap and you should care.

The good part is: since you're focusing on large file editing, you're basically in the best-case scenario for HDDs.

More or less:
3.5", 7200RPM: ~200MB/s
3.5", 5400RPM: ~150MB/s
2.5", 7200RPM: ~120MB/s
2.5", 5400RPM: ~90MB/s

Of course this will be affected by load and how much capacity you use. These numbers are for scaling expectations, not forecasting actual performance.

You have to rethink the general workflow.
Can you afford a small drive in the PC and larger storage externally?
Large, fast 2.5" HDDs are quite expensive actually: a 1TB models (say: WD Black) cost roughly as much as 500GB SSDs.
Miss 2 fancy lunches and you have a 1TB SSD.
And it's a single drive, so either way a small part of the PC cost.

The real HDD value kicks in when you need a lot of storage and you go for high-capacity 3.5" models.

So, the problem with your question is that the size of the disk isn't directly related to the speed of the disk.

I feel like there's a bit of confusion in this topic (even before it derailed to backups and SSD endurance ).

Yes, disk size (actually: platter size) affects transfers.

Essentially, longer (outer) cylinders mean more data can be accessed in a single rotation.
This has a significant impact on sequential r/w and - to less extent - also on random access.

For the similar fundamental reason, more dense (i.e. larger capacity per platter) drives have better sequential transfers as well. That's the main reason why HDDs are getting faster over time.

A 5.4k RPM 2.5" HDD will almost certainly be slower than a 7.2k RPM 3.5" HDD.

Yes.

But a 10k RPM 2.5" HDD will almost certainly be faster than a 7.2k RPM 3.5" HDD.

"It depends".

I don't think I've ever seen a 2.5" HDD get past 100MB/sec. A decent modern 3.5" HDD tends to do 150-200MB/sec at best.

Well, actually there are WD Black 2.5" 7200RPM models that will, easily.

Also, some of the high-speed drives from the past, like WD VelociRaptor (10kRPM) or Seagate Cheetah (15kRPM) also used small 2.5"-like platters - they're just easier to spin that fast.
And whereas Cheetah was a normal 3.5" form factor, VelociRaptor was actually a proper 2.5" HDD sold with a detachable 3.5" radiator.

And in my experience, when an SSD goes faulty, you're lucky if it doesn't go completely titsup at a moment's notice.

That's something I agree with, though. Because of the mechanical nature, you usually get some signs that a disk may die soon (noise, heat, bad sectors etc).
SSDs basically look perfectly fine up to the moment they die instantly.

But this shouldn't be seen as an SSD disadvantage.
In the end - they work better near the end. It is a plus.

And you should never postpone backups until a HDD "shows signs".

 

[coercitiv]

I agree that SSDs are not too expensive unless you are trying to get a high capacity one. I have one of those Intel 660p TB drives you speak of. But when you fill up disks and have 200GB free then repeatedly copy over 128GB SD cards, you put a lot of wear on the drive because you are constantly writing to the same cells.

You're not writing on the same cells, the SSD actually ends up moving data around to keep the same cells pilling up way more writes than the rest. That helps to even out the write cycles but also leads to "write amplification", where writing 1X data will result in more than 1X effective writtes as the SSD also moves data around. (ex: 1TB of files copied, 1.4TB written to NAND)

Considering your setup I would increase storage both ways: a couple of 2.5" HDDs to help expand your storage capacity, while also adding one more SSD drive for fast writes. In your case I would strongly consider designating one of the SSDs as "trash" drive that takes most of the writes during work sessions, while other drives are used for less writes for "final" work. (if possible ofc)

• Make sure the SSDs which see high amounts of writes have extra over provisioning. Nowadays this may no longer be required on normal consumer loads, but yours is... atypical. Over provisioning will help keep write amplification down and performance up.
• Make sure the HDDs you buy are not using SMR, or if they do make sure you understand what that means for the usage pattern they will be good for. (more like backups, archiving, light/medium activity, not time sensitive data transfers)

Last but not least - buy SSDs with high endurance ratings, such as the consumer 3D MLC drives from Samsung or better yet data center products from either Samsung or Intel. Data Center SSDs will be more expensive than consumer stuff, but will also come with far higher endurance and better circuitry. The consumer 850/860 Pro may still be a great value option if you can find them at a good price.

So, to sum things up:
1. Buy 2.5" HDDs for archiving, backup, or generally offloading data from SSDs to keep up free space.
2. Get a high endurance SSD drive as "trash" drive to protect your other disks.
3. As time goes by naturally replace all of your drives with high endurance models.