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How fast SSDs slow to a crawl: thermal throttling (2021)

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Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#41

Post by marginalia_nu »

ChuckNorris89 wrote: post #3

I did not see any temperature measurements of the controller though in this article so the test doesn't feel very scientific to me. It's not just thermal throttling of the controller that causes slowdown, it's also the filling of the DRAM/SLC cache. Also, we should talk more about some vendors screwing over customers by replacing controllers or NAND chips with slower parts to cut down cost while keeping the same SSD…

Besides what you've mentioned, overprovisioning/garbage collection may also cause slowdowns after sustained writes.

The more I've worked with SSDs to try to get them to perform well, the more I've come to realize benchmarking SSD performance is virtually impossible to do in any meaningful sense, because they themselves are stateful and your performance is highly dependent not only on what you are doing now, but what you did a few moments ago. There's also a bunch of protocol-level behavior adding to this, as well as os-level behavior that may be difficult to isolate, and even if you succeed, yeah, you're benchmarking the device in an unrealistic fashion unlike any actual real world usecases so congrats I guess.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#42

Post by Robotbeat »

The irony is that flash write endurance for modern flash chips is actually greater if the writes are at higher temperature. Charge mobility is greater, and the writing damages the cells less.

Unpowered persistence is the opposite, however. At 85 Celsius, the data may last only single digit days unpowered by at freezing temperatures could last hundreds of years unpowered. For the same reason, I believe: charge mobility is lower at lower temperatures in semiconductors.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#43

Post by mschuster91 »

k8sToGo wrote: post #9
jagermo wrote: post #6

Earlier quoted context omitted.

Are there any programs that can track temperature for different vendors? I'd love to run a few ssds through a benchmark and have hard data for thermal data.

You can read the temperature from SMART interface.

Only if the interface exposes it. USB ones in my experience outright don't support it or mess it up somewhere in the chain; the only place I got SMART reliably to work was with a direct SATA attachment to a controller.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#44

Post by sandworm101 »

0-_-0 wrote: post #14
ChuckNorris89 wrote: post #3

I did not see any temperature measurements of the controller though in this article so the test doesn't feel very scientific to me. It's not just thermal throttling of the controller that causes slowdown, it's also the filling of the DRAM/SLC cache. Also, we should talk more about some vendors screwing over customers by replacing controllers or NAND chips with slower parts to cut down cost while keeping the same SSD…

The tested SSD indeed has an SLC cache which likely filled and the author misinterpreted the cause of the throttling as thermal.

The only meaningful way to prove thermal throttling (in any part) is to cool it down and see if that corrects the problem. This author did not do that. Correlation is not causation.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#45

Post by Arrath »

kkielhofner wrote: post #30

Glad to see attention brought to this issue. I recently started using these: ASUS Hyper M.2 X16 PCIe 4.0 X4 Expansion Card Supports 4 NVMe M.2 (2242/2260/2280/22110) up to 256Gbps for AMD 3rd Ryzen sTRX40, AM4 Socket and Intel VROC NVMe Raid https://www.amazon.com/dp/B084HMHGSP/ref=cm_sw_r_cp_api_i_ZY... If you have a spare x16 slot I highly recommend. I’ve torture tested the latest and greatest hot screaming NVMe dr…

Having no need for 4 expansion slots, I got this last year:

SilverStone Technology M.2 PCIE Adapter for SATA or PCIE NVMe SSD https://www.amazon.com/gp/product/B075ZNWS9Y/

Its worked like a charm. I've only put a drive into the M.2 slot so far.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#46

Post by kkielhofner »

someotherperson wrote: post #40
kkielhofner wrote: post #30

Glad to see attention brought to this issue. I recently started using these: ASUS Hyper M.2 X16 PCIe 4.0 X4 Expansion Card Supports 4 NVMe M.2 (2242/2260/2280/22110) up to 256Gbps for AMD 3rd Ryzen sTRX40, AM4 Socket and Intel VROC NVMe Raid https://www.amazon.com/dp/B084HMHGSP/ref=cm_sw_r_cp_api_i_ZY... If you have a spare x16 slot I highly recommend. I’ve torture tested the latest and greatest hot screaming NVMe dr…

Is there any real benefit over some thermal pads and heat sinks? I've passively cooled CPUs to idle at 40 degrees and max out at 60 degrees during benchmarking. I imagine $10 worth of pads and heatsinks would achieve the same outcome as this expansion card.

In my use case I needed to support four x4 NVMe drives (actually eight NVMe across two x16 slots). The low temperatures in a very dense chassis by doing nothing other than mounting the drives is a nice bonus!

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#47

Post by opan »

MomoXenosaga wrote: post #26

Isn't thermal throttling good? Without that safety measure you'll break your PC. I don't care if climate change kills millions of people. It impacts my summer gaming sessions. I need AC!

Generally it means something isn't working right, and your performance under the throttling can be quite bad. Sometimes a small undervolt is enough to avoid the issue, increasing overall performance.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#48

Post by kkielhofner »

jeffbee wrote: post #35
kkielhofner wrote: post #30

Glad to see attention brought to this issue. I recently started using these: ASUS Hyper M.2 X16 PCIe 4.0 X4 Expansion Card Supports 4 NVMe M.2 (2242/2260/2280/22110) up to 256Gbps for AMD 3rd Ryzen sTRX40, AM4 Socket and Intel VROC NVMe Raid https://www.amazon.com/dp/B084HMHGSP/ref=cm_sw_r_cp_api_i_ZY... If you have a spare x16 slot I highly recommend. I’ve torture tested the latest and greatest hot screaming NVMe dr…

Most SSDs have temperature thresholds at 85C or higher. Why do you care if yours maintains 40C?

I noted in another comment I needed eight x4 NVMe across two x16 slots in a very dense chassis. I was pleasantly surprised at the temperatures.

The hardware is in a colocation facility and I like to have plenty of buffer with standard operating temperatures in case of a cooling failure, etc. Is maintaining 40C necessary under normal conditions? Nope, but it's definitely a nice to have regardless.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#49

Post by sixothree »

ChuckNorris89 wrote: post #3

I did not see any temperature measurements of the controller though in this article so the test doesn't feel very scientific to me. It's not just thermal throttling of the controller that causes slowdown, it's also the filling of the DRAM/SLC cache. Also, we should talk more about some vendors screwing over customers by replacing controllers or NAND chips with slower parts to cut down cost while keeping the same SSD…

I have observed thermal throttling on a plastic Sandisk SSD poorly located in my case. It has nothing to do with usage and is 100% a thermal issue.

Re: How fast SSDs slow to a crawl: thermal throttling (2021)

#50

Post by klysm »

marginalia_nu wrote: post #41
ChuckNorris89 wrote: post #3

I did not see any temperature measurements of the controller though in this article so the test doesn't feel very scientific to me. It's not just thermal throttling of the controller that causes slowdown, it's also the filling of the DRAM/SLC cache. Also, we should talk more about some vendors screwing over customers by replacing controllers or NAND chips with slower parts to cut down cost while keeping the same SSD…

Besides what you've mentioned, overprovisioning/garbage collection may also cause slowdowns after sustained writes. The more I've worked with SSDs to try to get them to perform well, the more I've come to realize benchmarking SSD performance is virtually impossible to do in any meaningful sense, because they themselves are stateful and your performance is highly dependent not only on what you are doing now, but what…

Typically there are a few primary modes of the state. It’s useful to understand the performance under each mode. Even if you want predict exactly what mixture of modes you’ll be in, you can have a good guess if you’ll be in some pathological behavior based on your workload.
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