Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
M.2 Drives Have An Overheating Problem
Quote:We're not going to sugarcoat it - the SM951 runs really, really hot. This is not at all unique to the SM951, however. Every single M.2 drive we have tested that runs at PCI-E x4 speeds runs as hot or even hotter than this drive.

[Image: pic_disp.php?id=37286&width=650]

As you can see, the SM951 does run cooler than the XP941 by about 5-7 ºC, but it still reached a peak temperature of 110 ºC. This wasn't after hours of benchmarking in a closed box either. The SM951 hit 100 ºC after only about a minute and 110 ºC after only about three minutes on our open air test bench.

If you notice the slight dips in temperature that occur at about the 150, 190, and 220 second mark, each of those occurred right wen the controller hit 111 ºC for a split second. Since hitting that temperature immediately caused the temperature to drop we believe the drop in temperature to indicate when the drive automatically throttles itself to keep from overheating. Anandtech, Legit Reviews, and many other review sites have shown how quickly the SM951 throttles itself due to high temperatures.

If you prefer a video over a chart, we also recorded a video showing exactly how hot both the SM951 and XP941 run when doing a simple file copy:

The high temperature of both these drives really make us consider them to not truly be M.2 drives, but rather PCI-E drives that are missing their mounting hardware. There will be some users who will run one of these drives naked in a M.2 slot, but in our opinion the only way to use these drives is to either combine them with a PCI-E adapter that includes a heatsink (we use this adapter ourselves) or otherwise affix a heatsink to the controller chip to help dissapate the heat. Not only is 110 ºC hot enough to impact the longevity of the drive, the fact that the drive throttles around that temperature also means that you will not get anywhere near peak performance unless you add additional cooling via a heatsink.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
90 c is considered the top end of heat of chips so this is a huge screw up on someone's part.
Wow, thanks for sharing, SC. 111-120 degrees C is insane, and the throttling is unethical to begin with - there should be a warning label all over the retail box that it would throttle even in an open case.

I wonder how bad the throttling really is, in terms of real-world performance?
Ok with science that the big bang theory requires that fundamental scientific laws do not exist for the first few minutes, but not ok for the creator to defy these laws...  Rolleyes
Throttling is the least of the problems. The drive will die prematurely from that heat.
Now the 950 Pro M.2 is overheating, although not quite as bad as the SM951 and XP941.
Quote:To see how hot this drive gets, we did a simply file copy of ~205 GB worth of ISO files. As you can see, the 950 Pro does run cooler than the SM951 by about 5-12 ºC, but it still reached a peak temperature of 98 ºC on the controller chip (the storage RAM itself does not get anywhere near as hot). This isn't doing hours of benchmarking in a closed box either - just a simple file copy on an open test bench. Doing this, the 950 Pro hit 97 ºC after only about a minute and 98 ºC after about 3 minutes compared to the SM951 which hit 100 ºC after about a minute and 110 ºC after only about three minutes.

What is really interesting is that until the 950 Pro hit 97 ºC, both it and the SM951 had nearly identical temperatures. In addition, during this period Windows reported identical file transfer speed of about 700-800 MB/s for both drives. After the 950 Pro hit 97C, however, the transfer speed on the 950 Pro dropped to around 400-500 MB/s which it maintained for the duration of the file copy. The SM951, on the other hand, sustained the 700-800 MB/s transfer speed except for around the 150, 190, and 230 second mark where you can see a slight dip in temperature. At each of those points the controller on the SM951 hit 111 ºC for a split second and the paused the file transfer until the temperature dropped to below 100 ºC.

Due to the fact that the Samsung 950 Pro throttles sooner than the SM951, we actually saw much lower sustained performance on the 950 Pro than we expected. To copy all 205GB worth of ISOs, the 950 Pro took about 365 seconds while the SM951 only took about 274 seconds. This translates to a sustained file copy performance of about 562 MB/s for the 950 Pro and about 748 MB/s for the SM951. In other words, while the Samsung 950 Pro does have lower temperatures than the SM951, it achieves this by being much more aggressive in it's throttling.

In our opinion, we actually prefer the earlier throttling on the 950 Pro. 98 °C may still be extremely hot, but it is much better than 111 °C. In fact, while Samsung even mentions throttling on the overview page for the 950 Pro:
Quote:The 950 PRO also features Dynamic Thermal Throttling Protection technology, which controls the temperature of the device to reduce overheating and maintain a high level of sustained performance.
Samsung's overview page for the 950 Pro makes it clear that this drive is designed to throttle when the drive gets hot so the high temperature on the controller shouldn't impact the longevity of the drive. However, even if you are willing to trust that Samsung has addressed the high temperatures appropriately, you still will see a drop in performance if this drive gets too hot. And since that happens after only about a minute of sustained file transfer, it is likely that most users will run into this throttling at some point.

If you want a high performance drive that is able to achieve the advertised performance over prolonged periods of time, we would highly recommend using this drive in combination with a PCI-E adapter that includes a heatsink (we use this adapter ourselves) or otherwise affix a heatsink to the controller chip to help dissapate the heat.

The biggest issue we have with the 950 Pro is one that seems to come up often with high performance NVME drives - temperature. The 950 Pro does run cooler than older NVME drives, but the controller still easily hits 98 °C at which point the drive throttles. We were hoping that the move to V-NAND would improve the controller temperature, but it appears that this is not the case. All this really means is that if you want to be able to maintain the full speed this drive is possible of at all times you will need to use a M.2 to PCI-E adapter with a heatsink. On the other hand, Samsung publicly advertises the throttling capability of this drive so if you are willing to see some performance throttling it should be completely safe to use it without a heatsink if you wish.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
Throttle my ass, no circuit should be allowed to go to production with the chips going over 90C
wholly crap!

This is really surprising!!!
(11-02-2015, 11:22 AM)dmcowen674 Wrote: Throttle my ass, no circuit should be allowed to go to production with the chips going over 90C


perhaps you never heard of AMDs 290x
Quote:When introducing the 950 Pro, Samsung assurred us that it could manage its heat output. They were right: the 950 Pro achieves a delicate balance where it will almost never overheat from a typical consumer workload, but almost any stress test can trigger sometimes severe thermal throttling. That isn't to say that the heatsink will never help in the real world; those situations are just rare, and even with the thermal throttling it would only take a few minutes to read or write the entire drive. For example, with a heatsink the 512GB 950 Pro is capable of saving an uncompressed 4k 60Hz video stream in realtime, but it'll fill up in six minutes. Other bulk data manipulation like file system or virtual machine snapshotting could be sped up some with a heatsink (provided the task consists of more than just random reads), but in general for consumer hardware and workloads the only source or destination for data that can keep up with the 950 Pro is RAM or another SSD.
The dramatic sustained performance improvements enabled by the Wings PX1's heatsink also highlight how modern power efficiency and thermal management design tradeoffs have caught up to the M.2 form factor. With M.2 being designed first and foremost for laptops, it's not very surprising to see that many of the same performance tradeoffs that we already see with laptop CPUs and GPUs have come into play for SSDs as well. In the mobile space we essentially take it as a given that these devices have sustained performance that's going to be lower than their peak performance, a consequence of balancing between performance needs and device size & noise. As current reasoning goes, most client workloads are very bursty and only need peak performance for a short period of time; and while we can certainly dig up counterpoints to this when it comes to CPUs and GPUs, this is admittedly harder with SSDs, especially when the time to completely fill a drive is only a couple of minutes longer than the time it takes to heat up a drive to begin with. In other words, right now PCIe SSDs are a great example of client burst workload optimization in action.
As for the the Samsung 950 Pro, it attains great performance on client workloads, but without extra cooling its performance on the heaviest of workloads is being held back. If the 950 Pro's successor is to offer increased real-world performance, it will have to also be significantly more efficient in order to keep thermal throttling out of consumer usage scenarios. In the meantime we are probably approaching a plateau for the sustained performance that a bare M.2 drive can offer.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
Quote:In an ideal situation, every component in the system is idle and producing a minimal amount of heat. In this situation, we are showing what should be the longest the Samsung 950 Pro can go without throttling due to drive temperature.

There is a lot of data crammed into the charts above, but the main thing to look at is how quickly the different slots start to throttle and what speeds they throttle to. The charts above can largely be summarized into the following:

It is clear that the "Upright M.2 Slot" takes the longest to start throttling and runs at consistently higher speeds than the other slots. In general, this slot took between ten and thirty seconds longer to start throttling and after throttling was up to 500 MB/s faster than some of the other slots! One thing we will point out is that the Random Read performance of this slot looks poor, but that is actually due to the X99 chipset and not due to the drive throttling.

For the other locations, the top and bottom slots were pretty similar. The bottom slot was better with only a single GPU but the top slot was actually slightly better with dual GPUs. However, both locations were better than the underside slot which ended up throttling to about half the performance the Samsung 950 Pro is capable of.

Worst case (heavy system load) results

While the previous section is a good indication of how soon a Samsung 950 M.2 drive might throttle in ideal situations, it is often the case that the system will be under a load when you need to access the drive. To simulate these situations, we loaded the GPU(s) with Furmark to increase the ambient temperature within the chassis. Note that we did not put a heavy load on the CPU because we wanted to avoid creating a CPU bottleneck that might cause lower results from our benchmark.

Compared to the ideal situation in the last section, loading up the video card(s) to increase the ambient temperature caused the M.2 drive to throttle much sooner. In the worst case, the drive was throttling after only 6 seconds and ended up slower than a standard SATA SSD! Once again, if we primarily look at the sequential read and write performance, the charts above can largely be summarized into the following:

Once again, the upright M.2 slot was by far the best slot position. This slot took significantly longer to start throttling than the other slots and especially with two GPUs it throttled much less aggressively. The performance of the Samsung 950 Pro was still cut roughly in half, but that is actually much better than what we saw with the other slot locations.

For the other locations, the bottom M.2 slot was the next best performer - taking roughly twice as long to start throttling than the top slot. It ended up at about the same speed as the top slot with a single GPU, but with two GPUs it ended up noticeably faster.


A lot of our test results really surprised us. We knew that M.2 drives would throttle if they got too hot, but we didn't know that we could cause it to happen so quickly or quite to the extent we measured. There are really three main conclusions that we came to:
  1. The temperature reported by utilities such as AIDA 64 is not useful to gauge whether the drive is close to throttling or not. As we discussed in the test setup section, this is due to the fact that the Samsung 950 Pro actually has two thermal sensors, but only the sensor near the storage chips (not the control sensor) is being read. As far as we could find, it is not possible to read from the sensor that controls the drive throttling - but if anyone knows of a program that will read this sensor data, we are very interested to hear about it.
  2. The ambient temperature within the system has a massive effect on when the drive throttles. It makes sense that a drive will throttle sooner in a hotter environment, but in the worst case we were seeing throttling in as soon as six or seven seconds!
  3. The more exposed the M.2 drive, the longer it takes to throttle. Once again, this seems like a common sense point, but it ended up making a bigger difference than we thought. Especially when the system was put under a load, the upright M.2 slot (with the most open space around the drive) resulted in significantly less throttling than any of the other slots.
One thing we want to point out is that it is pretty uncommon to fully utilize a drive this fast to the same extent we did in this article. Very few programs will actually be able to read from a Samsung 950 Pro at full speed for more than a very short period of time - often the drive will have to regularly wait on the CPU or some other component to actually process the data. In truth, the most common situation you might run throttling is going to be if you have two M.2 drives and you are copying large amounts of data from one drive to the other.

Also, keep in mind that if you absolutely need a super fast drive to perform at full performance for longer periods of time, there are a number of alternatives you might consider. The first would be to use a U.2 drive instead like the Intel 750 series. As we showed in the control section, the Intel 750 did not throttle at all yet is very close in performance to the Samsung 950 Pro. Not many motherboards have U.2 support quite yet and the Intel 750 is a bit more expensive, but it should give you maximum performance all the time. Another solution would be to attempt to cool a M.2 drive with additional airflow or a heatsink in order to increase the time it takes to begin throttling. If you are interested in that option we performed further testing in our M.2 Drive Additional Cooling Testing article investigating a range of cooling methods.

We corresponded with Geoff Gasior from Asus throughout our testing and they were even kind enough to provide the motherboards we used for our testing. If you would like to view their take on the results, head over to their article:
M.2 SSD throttling tests vindicate ASUS motherboard designs
Quote:In a recent article, we investigated how long it takes for a Samsung 950 Pro M.2 drive to throttle in a number of different M.2 slot locations and some of the results surprised us. In fact, in one instance we measured a 75% drop in performance after only 7 seconds!

If you are purchasing a M.2 drive because you need high transfer speeds, seeing our results probably threw up a big red flag for you. Having a high speed drive is great, but not so much if the speed only lasts a couple of seconds. Luckily, in most situations the Samsung 950 Pro drive actually lasts a good amount of time under full load before it begins to throttle. For those that need a M.2 drive to run at full speed for longer periods of time, however, we decided to run some quick tests to compare a number of different M.2 drive cooling methods.

If you prefer to skip all our testing and simply view our conclusions, feel free to jump ahead to the conclusion section.
Compared to just a stock Samsung 950 Pro M.2 drive without any additional cooling, every single method we tested did extremely well. Even in the worst case with the simple aluminum bar heatsink, the drive took 2.5 times longer before it started to throttle compared to the stock M.2 drive with no additional cooling. If we were to rate the different methods from most to least effective, they would be:
  1. Tie between PCI-E Adapter w/ Heatsink, 120mm 12V Quiet Side Fan, 92mm 12V High Flow Side Fan. All three of these methods completely prevented the Samsung 950 Pro drive from throttling during our testing. If you fully load the drive for longer than we did (which would mean you need to read more than 875GB worth of data from a 512GB drive), the high flow side fan should perform better than the quiet side fan, but in a practical sense all three of these methods should effectively be able to prevent a Samsung 950 Pro drive from ever throttling
  2. 120mm 5V Quiet Side Fan. While this cooling method was not able to completely prevent the drive from throttling when the system was under load, it allowed the drive to take 3-5 times longer to throttle and after throttling was 50% faster than a stock Samsung 950 Pro. For such a small amount of airflow, this is a much bigger difference than we expected and means you could read 455GB of data (nearly the entire drive) or write 172GB of data continuously before you saw any drop in performance.
  3. Aluminum Bar Heatsink. Technically, this was the worst cooling method we tested but it was still a massive improvement over the stock drive without any cooling. The main downside to a simple heatsink like this is that the hotter the system gets, the less effective a heatsink can be. We only tested with a single GPU, but if you had two or more video cards under full load, it is very possible that a heatsink may be no better than a bare drive or in some situations may cause the drive to throttle even sooner.

The different methods we tested really boil down to two types of cooling: passive cooling with a heatsink and active cooling with a fan. Both can make a big difference, but one thing that was clear in our testing is that even a small amount of airflow over the drive can be extremely beneficial. While we did not specifically test it, even better would be to combine the two methods by having a heatsink on the drive along with a fan providing some airflow over the heatsink.

Keep in mind that in the real world, it is very uncommon to fully utilize a drive this fast to the same extent we did in our testing. Very few programs will actually be able to read from a Samsung 950 Pro at full speed for more than a very short period of time, but if you do have a situation where you need a M.2 drive to perform at full speed for longer periods of time this should give you an idea of what you may need to do to achieve this.
Quote:Puget Systems did most of its testing on our Z170-WS, which has M.2 slots below the primary PCIe x16 mid-way up the board and below the secondary slot toward the bottom. They also tested the vertical M.2 slot on our X99 Deluxe, a unique configuration mirrored in the new X99-Deluxe II, and the underside slot on our H170I-Plus D3, a typical location for Mini-ITX motherboards with insufficient space topside.

The big news is that 950 Pro was unable to sustain its peak sequential speed in all four locations, regardless of whether the system was idling or occupied with a heavy graphics load. Throttling kicked in after as little as seven seconds of sustained testing or as much as 70. The declines were significant, too: from 40-70% with a single graphics card and 55-76% with two. Matt Bach, who conducted the testing and has previously demonstrated throttling on the 950 Pro and other Samsung M.2 SSDs, was particularly surprised by how quickly the new drive throttled in thermally challenging environments.
The underside slot has less airflow than any of the other positions. Predictably, the 950 Pro exhibited the most severe throttling in this location—and the biggest performance hit with a single graphics card under load. This is especially problematic because Mini-ITX motherboards typically don’t have room to put their M.2 slots anywhere else. The only other option is the PCI Express x16 slot, which is usually reserved for a graphics card

When designing our Maximus VIII Impact, we had to choose between an underside M.2 slot and a native U.2 port. Offering both would have required extra layers, inflating not only the cost of the board, but also the development time required to bring it to market. Since the Impact is all about bringing the best performance to Mini-ITX, we went with U.2 to avoid throttling issues that had been documented with other M.2 drives at the time. We caught some flak from people who wanted to build Mini-ITX rigs with M.2 drives, but Puget’s results support our decision. The 750 Series U.2 SSD showed no signs of temperature-induced throttling in any of the tests.

Frankly, we shouldn’t be surprised. The U.2 interface has four PCIe Gen3 lanes, just like current M.2 slots, but it uses a cabled connection that lets drives reside in standard cages, where they can benefit from natural chassis airflow. The larger form factor also leaves plenty of room for a heatsink to further aid cooling, and the 750 Series takes full advantage by integrating one into its shell.

We’ve long been aware of the benefits of U.2 storage, which is why native ports are integrated on several of our high-end motherboards, including the Maximus VIII Hero Alpha, Formula, and Extreme. The Z170-WS used in Puget’s testing has U.2 onboard, too, as do our latest X99-A II, X99-Deluxe II, Strix X99 Gaming, and Rampage V Edition 10. With the exception of the Maximus VIII Impact, all these boards also have M.2 slots.

If you still want to run an M.2 drive, the Puget’s companion post shows that a dedicated cooling fan or full-sized adapter card with heatsink can minimize throttling on the 950 Pro, if not eliminate it entirely. The company even sells the adapter, but Bach told us it tends to favor the 750 Series in desktop builds instead. The 950 Pro is used in notebooks, where there’s usually more ventilation—and no hot components in the immediate vicinity.

Serial ATA SSDs still outsell their PCIe counterparts by a huge margin—about 12:1 at Puget Systems—so it’s important to keep things in perspective. The fact is that SATA SSDs are fast enough for the vast majority of desktop applications. The one Puget System tested for throttling didn’t exhibit any, either.

Speaking of perspective, we should also reiterate that throttling was only evident under sustained loads. The 950 Pro takes some time to heat up, and outside of targeted benchmarks, most everyday storage loads are too short to trigger throttling. But we’d be critical of a CPU or GPU that behaved the same way, so it’s hard to give this story a positive spin. The best we can offer is a range of motherboards that situate their M.2 slots clear of potential hot spots, plus plenty of options with U.2 ports that let you avoid the problem entirely.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
And cue the downplaying:
Quote:The Samsung 950 Pro 512GB flagship SSD would enter the thermal throttle state after 63 seconds of reading data and 65 seconds of writing data. The drive would read 158GB of data and write 93GB of data during that time. You would need to transfer more than three Blu-Ray ISO files from the drive to another high-speed storage product to reach the throttle threshold. Going the other way, you would need to write two full-size Blu-Ray ISO files to the drive to kick into the thermal protection mode.

Samsung increased the thermal performance with the 960 Pro, which can now read for 95 seconds and write for 147 seconds before throttling. Samsung's new Dynamic Thermal Guard technology employs a combination of an improved management algorithm and a novel sticker to combat any thermal throttling issues. The new sticker has a copper film embedded in between the layers, so it acts as a heatsink for the entire drive. The sticker reduces the SSDs temperature, and it even works in restricted airflow environments, like laptops.

If you ever find yourself in "Limp Mode" and need to solve the troubling condition, then the 960 Pro is the answer. The new series doubles the amount of data you can read and triples the amount of data you can write before thermal throttling slows the transfer down. The new limit kicks in after transferring the equivalent of six full Blu-Ray ISO files to the drive (or reading seven ISOs). The nitpickers can now rejoice.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
Quote:Overall, the Samsung 960 Pro is an excellent improvement over the 950 Pro. Not only is the raw performance of the drive better, but Samsung has greatly improved how long the drive can handle heavy loads before throttling. It is still certainly possible to cause the drive to throttle eventually, but it takes long enough to do so that the vast majority of users would never encounter it.

We already listed the advertised performance of both the 960 and 950 Pro earlier in this article (and there was nothing in our testing to indicate they are incorrect), but we did want to give a summary chart for how quickly these drive will throttle:

While the fact that the 960 Pro takes much longer to throttle (2-4 times longer in fact) is terrific, what is really impressive is how much more data you can actually read or write before the throttling occurs. Since the 960 Pro is a faster overall drive, you can actually read or write between three and six times more data before the throttling kicks in. While that is great in and of itself, it also means that throttling in general is much less likely to happen. Sequentially writing 72 GB of data is hard enough to do at the 1.5 GB/s speed of the Samsung 950 Pro, and doing so for 336 GB of data at over 2 GB/s is going to be even more rare.

We don't quite want to say that thermal throttling is something you never need to worry about with the 960 Pro, but what we are willing to say is that unless you have a piece of software that is capable of reading or writing hundreds of GB of data at 2-3.5 GB/s, you are very unlikely to ever encounter throttling. And even if you do, when the 960 Pro throttles it tends to still be faster than the 950 Pro at it's best, so you probably would not notice the drop in performance.

Keep in mind that the throttling we saw was largely due to the controller on the M.2 drive overheating. Our testing was done with the system at idle, so if your system has a number of hot components and poor ventilation around the M.2 drive, a 960 Pro (or any M.2 NVMe drive for that matter) will likely throttle faster than what we recorded. If you are concerned about this and want to ensure your drive will never throttle, we recommend using a PCI-E adapter card with a built-in heatsink (we use the Bplus M2P4A here at Puget Systems) to help improve the cooling.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
Quote:It’s not all smooth sailing, though, because even the Samsung 960 Pro runs hot when faced with certain workloads; the inevitable side-effect of dissipating lots of heat into the small, M.2 footprint. If the 960 is anything to go by, thermal management is going to be an issue we need to deal with for the foreseeable future. That’s why we reassessed location of M.2 slots on the ASUS Z270 series motherboards. Unlike their Z170 counterparts that featured a single M.2 slot, the Z270 boards have two. Where possible, we’ve repositioned the slots to avoid hot zones, and, where necessary, we’ve developed solutions to help keep drives cool, such as heatsinks, and 3D-printable fan mounts. Together, these enhancements enable drives to deliver consistent performance and aid their longevity.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.

Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
The debate rages in the comments.
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.
SilverStone has released M.2 drive thermal pads:
Valve hater, Nintendo hater, Microsoft defender, AMD hater, Google Fiber hater, 4K lover, net neutrality lover.

Forum Jump:

Users browsing this thread: 1 Guest(s)