4 ms·

> The hard drive shows better write throughput and latency as compared to most of the tested SSDs. Yes, except for the initial few minutes where the cheap SSDs

> The hard drive shows better write throughput and latency as compared to most of the tested SSDs. Yes, except for the initial few minutes where the cheap SSDs tend to be faster (except for the Kingston & Crucial SSDs) but how much does that matter? I love the idea of this article, but it lost me here. “Except for the initial few minutes” is a weird thing to dismiss, since the majority of desktop operations will be done in less than a few minutes. Most are in the span of seconds. The only time someone will typically go past a few minutes of sustained writes is during very large file copy operations. It’s weird to put an emphasis on this relative edge case while downplaying the importance of burst performance. Anyone who has switched from even a fast hard drive to a cheap SSD can see the difference an SSD makes. It’s true that my NAS can sustain higher throughput for longer than a cheap SSD, but it’s much slower at doing directory listings and scanning random files than even the cheap SSDs.

glofish 4y ago
In a realistic use cases (unlike the ones in the test) the hard drives are accessed very often. For anything by very light use, I would expect the drives to be written just about at all times.
louwrentius 4y ago
It's quite clearly phrased in the article: Although cheap SSDs do perform fine regarding reads, sustained write performance can be really atrocious. Notice the sustained write performance. So you consider copying large files a fringe / or edge case, but personally, I'm not so sure. Especially for people who buy cheap 1TB or 2TB+ SSDs, they may be unpleasantly surprised when they copy some media files or start downloading a game from steam. Don't forget that it will take quite a while - due to the slow flash - to empy the SLC cache before you can benefit from it again. > Anyone who has switched from even a fast hard drive to a cheap SSD can see the difference an SSD makes. This article is not about the merrits of SSDs, that's a done deal, a good SSD beats an HDD by every conceivable metric. My point is that people should watch out for cheap SSDs, as their sustained write performance is so slow.
- wtallis 4y ago
  > Especially for people who buy cheap 1TB or 2TB+ SSDs, they may be unpleasantly surprised when they copy some media files or start downloading a game from steam. That would be an entirely different experiment. This one has highlighted the most important pitfall of using critically undersized SSDs, so its conclusions say next to nothing about multi-TB drives.
  - louwrentius 4y ago
    I'm not so sure given that the Crucial MX500 1TB already performed at the edge of bad, although it could sustain a gigabit download.
    - patshead 4y ago
      The Crucial MX500 is a rather old piece of hardware now. Tom's Hardware NVMe benchmarks include a "Sustained Write Performance and Cache Recovery" component. Whenever there's a good sale price on an NVMe, that is just about the only metric I hunt down now. Most of the worst drives they test will always beat a mechanical disk, but the worst drives Tom's Hardware ever tests are still decent drives. I grabbed one of the cheapest SATA SSDs last week to replacing a failing lvmcache drive. It is a NETAC 1 TB that might still be on sale on eBay for $34. I expected the worst, and I did want to test its sustained write performance, but I wasn't as nearly scientific as you! I just ran dd for a while and watched it stay between 420 and 470 megabytes per second for about 120 gigabytes straight before I stopped the test. The meanest I am to this cache is dropping 50 GB of video on two different days each month, so that was all the data I needed. Had I known that I would be reading your blog four days later I would have let the dd finish so I could take better notes! Thank you for taking the time to do the science for us!
      - wtallis 4y ago
        > The Crucial MX500 is a rather old piece of hardware now. Depends on when you bought it. Crucial/Micron decided to stop introducing new branding when they updated their SATA SSDs, but the hardware inside has changed several times to incorporate new generations of NAND flash memory, and probably at least one update to the SSD controller by now. None of that matters to the top-line specifications they advertise, but such changes can be relevant for more stressful, more thorough or less realistic benchmarks.
wtallis 4y ago
For tiny SSDs, it's also important to consider how the volume of data written compares to the total capacity of the drive. Having the horizontal axis of the graph be time kinda implies the test could keep going indefinitely. But if the data were recast in terms of % of the drive, it would be easier to see how quickly it runs beyond any realistic use case: re-writing more than half the drive in one operation is simply not how people use their drives except on rare occasions (eg. restoring from backup).
- joshspankit 4y ago
  I’d be interested to see some numbers that specifically keep that in mind. I suspect that flash drives suffer when they start to get full.
otterpro 4y ago
Copying big file is not a fringe case. I often find myself copying files that take more than a minute because I work with videos that I took on my phone and camera and for video editing. I also have lots of data, which need to be transferred frequently and it is frustrating when the SSD cache is exhausted during copy and as a result, it becomes even slower than my old spinning hard drive (HDD).
- wtallis 4y ago
  Copying big files onto a 120GB SSD is a fringe use case, unless it's an external SSD you're using to transport those files. Editing and organizing large videos is usually done on drives large enough to hold more than two of them (plus the OS and applications).
withinboredom 4y ago
Says everyone until they have a power loss event…

glofish 4y ago

In a realistic use cases (unlike the ones in the test) the hard drives are accessed very often. For anything by very light use, I would expect the drives to be written just about at all times.

louwrentius 4y ago

It's quite clearly phrased in the article: Although cheap SSDs do perform fine regarding reads, sustained write performance can be really atrocious. Notice the sustained write performance. So you consider copying large files a fringe / or edge case, but personally, I'm not so sure. Especially for people who buy cheap 1TB or 2TB+ SSDs, they may be unpleasantly surprised when they copy some media files or start downloading a game from steam. Don't forget that it will take quite a while - due to the slow flash - to empy the SLC cache before you can benefit from it again. > Anyone who has switched from even a fast hard drive to a cheap SSD can see the difference an SSD makes. This article is not about the merrits of SSDs, that's a done deal, a good SSD beats an HDD by every conceivable metric. My point is that people should watch out for cheap SSDs, as their sustained write performance is so slow.

wtallis 4y ago
> Especially for people who buy cheap 1TB or 2TB+ SSDs, they may be unpleasantly surprised when they copy some media files or start downloading a game from steam. That would be an entirely different experiment. This one has highlighted the most important pitfall of using critically undersized SSDs, so its conclusions say next to nothing about multi-TB drives.
- louwrentius 4y ago
  I'm not so sure given that the Crucial MX500 1TB already performed at the edge of bad, although it could sustain a gigabit download.
  - patshead 4y ago
    The Crucial MX500 is a rather old piece of hardware now. Tom's Hardware NVMe benchmarks include a "Sustained Write Performance and Cache Recovery" component. Whenever there's a good sale price on an NVMe, that is just about the only metric I hunt down now. Most of the worst drives they test will always beat a mechanical disk, but the worst drives Tom's Hardware ever tests are still decent drives. I grabbed one of the cheapest SATA SSDs last week to replacing a failing lvmcache drive. It is a NETAC 1 TB that might still be on sale on eBay for $34. I expected the worst, and I did want to test its sustained write performance, but I wasn't as nearly scientific as you! I just ran dd for a while and watched it stay between 420 and 470 megabytes per second for about 120 gigabytes straight before I stopped the test. The meanest I am to this cache is dropping 50 GB of video on two different days each month, so that was all the data I needed. Had I known that I would be reading your blog four days later I would have let the dd finish so I could take better notes! Thank you for taking the time to do the science for us!
    - wtallis 4y ago
      > The Crucial MX500 is a rather old piece of hardware now. Depends on when you bought it. Crucial/Micron decided to stop introducing new branding when they updated their SATA SSDs, but the hardware inside has changed several times to incorporate new generations of NAND flash memory, and probably at least one update to the SSD controller by now. None of that matters to the top-line specifications they advertise, but such changes can be relevant for more stressful, more thorough or less realistic benchmarks.

wtallis 4y ago

For tiny SSDs, it's also important to consider how the volume of data written compares to the total capacity of the drive. Having the horizontal axis of the graph be time kinda implies the test could keep going indefinitely. But if the data were recast in terms of % of the drive, it would be easier to see how quickly it runs beyond any realistic use case: re-writing more than half the drive in one operation is simply not how people use their drives except on rare occasions (eg. restoring from backup).

joshspankit 4y ago
I’d be interested to see some numbers that specifically keep that in mind. I suspect that flash drives suffer when they start to get full.

otterpro 4y ago

Copying big file is not a fringe case. I often find myself copying files that take more than a minute because I work with videos that I took on my phone and camera and for video editing. I also have lots of data, which need to be transferred frequently and it is frustrating when the SSD cache is exhausted during copy and as a result, it becomes even slower than my old spinning hard drive (HDD).

wtallis 4y ago
Copying big files onto a 120GB SSD is a fringe use case, unless it's an external SSD you're using to transport those files. Editing and organizing large videos is usually done on drives large enough to hold more than two of them (plus the OS and applications).

withinboredom 4y ago

Says everyone until they have a power loss event…