Samsung evo 970 write speeds low

zniff

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Jun 10, 2020
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i switched out an ssd from my gp72vr 6rf an MSI laptop with a Samsung evo 970
for some reason im getting low write speeds when running samsung magician benchmarks below 1000MB/s in write speed. i dont remember the earlier ssd name but it was an M.2 SATA ssd

Operating System
Windows 10 Home 64-bit
CPU
Intel Core i7 6700HQ @ 2.60GHz 88 °C
Skylake 14nm Technology
RAM
16.0GB Dual-Channel Unknown @ 1066MHz (15-15-15-35)
Motherboard
Micro-Star International Co. Ltd. MS-179B (U3E1)
Graphics
Generic PnP Monitor (1920x1080@60Hz)
Intel HD Graphics 530 (MSI)
3071MB NVIDIA GeForce GTX 1060 (MSI) 71 °C
SLI Disabled
Storage
931GB Hitachi HGST HTS721010A9E630 (SATA ) 52 °C
931GB Samsung SSD 970 EVO 1TB (Unknown (SSD))
Optical Drives
HL-DT-ST DVDRAM GUD0N
Audio
Realtek High Definition Audio
 
Can you post a screenshot of the drive from CrystalDiskInfo please!

Those numbers seem low for sure.
 
The problem is that Skylake mobile chipsets do not support the full PCI-E 3.0 x4 bandwidth on their m.2 sockets. Your laptop is one of those that cripple their m.2 sockets. Officially, your laptop's m.2 socket only supports PCI-E 2.0 x2 bandwidth at most on that m.2 socket. Thus, the sub-1000 MB/s read and write speeds are perfectly normal with your particular laptop.

If that laptop supported only SATA in its m.2 socket, then that 970 EVO would not have fit at all in that socket.
 
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Interesting. OP lists gp72vr 6rf as the model, which touts PCIe Gen3 on the M.2 slot. The conclusion drawn by E4g1e or Maxx lines up with what you are receiving performance wise. You definitely don't have an HM86 chipset though - that chipset only supports Haswell CPUs and not the Skylake one you have. Combined with the claimed support for PCIe Gen3, even on an x2 slot you should get more than >1000 MB/s.

Now then, it's possible that MSI's spec page is simply wrong, and the included M.2 slot does not in fact run at Gen3 speeds, in which case you are running 2.0 x2 and are right in line with what you should expect performance wise. That'd be pretty shitty of MSI though, since the HM170 chipset definitely supports PCIe 3.0 and should have enough lanes to go around to support a decent M.2 slot.

CrystalDiskMark will show you your PCIe link speed on your SSD. If you are running at 2.0 x2, then your performance is right where it is supposed to be and there is nothing to worry about. If you are linked at Gen3 x2, then you might have cause for concern because your drive is underperforming.
 
when i bought the laptop it told about giving 2300 write speed on that socket. weirdly read is maxed out at 3500MB/s
 
The problem is that Skylake mobile chipsets do not support the full PCI-E 3.0 x4 bandwidth on their m.2 sockets.

Incorrect
The Skylake and 100 series chipsets is when the 3.0 spec and DMI 3.0 where implemented. The only exception was with the H110 chipset: https://en.wikipedia.org/wiki/LGA_1151#Skylake_chipsets_(100_series) and https://ark.intel.com/content/www/us/en/ark/products/series/98456/intel-100-series-chipsets.html. To note, although can be incorrect themselves due to chipset not being listed and other "technicalities, " the specification for the laptop are noted: 1x M.2 SSD Combo (NVMe PCIe Gen3 / SATA ). By "technicalities" we do not know how the PCIe routing is done (caveat emptor!), and there may be limited routing and support for the interface. Just to mention, Magician will also inform if the driver is Windows or Samsung's, and the PCIe allocation and interface type.



As for the issue, you cannot expect that since you have the 970 and its write speed is capable of XGB/s that it will equal the performance, or better. Now, the main considering aspect of your performance is due to you having a laptop with many thermal and power saving features implemented (enabled). With desktops this is very moot and also usually an issue because of motherboard EFI configuration code implemented-which many Linux users know about; and why many times it [LSPM / ASPM] is disabled to those that know via Power Configuration.

I would consider your power profiles and PCIe configuration settings with Window's Power Configuration, and also check the driver because it can be a generic and not the provided driver from Samsung. However, if the device is OEM then there will only be the driver provided by Windows NVMe. There was a known issue, possibly resolved, when a power feature cause lesser performance back in the 960 days using the generic NVMe.

Also, toggle to disable the Windows write buffer cache flushing in Device Manager. This always should be toggled to prevent flushing of the buffer.

One last thing is the mitigation updates did affect the performance of I/O with this generation, and should also be considered in the overall performance. There personally was a difference with my 6700K/Z170 with SATA and NVMe.
 
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Incorrect
The Skylake and 100 series chipsets is when the 3.0 spec and DMI 3.0 where implemented. The only exception was with the H110 chipset: https://en.wikipedia.org/wiki/LGA_1151#Skylake_chipsets_(100_series) and https://ark.intel.com/content/www/us/en/ark/products/series/98456/intel-100-series-chipsets.html. To note, although can be incorrect themselves due to chipset not being listed and other "technicalities, " the specification for the laptop are noted: 1x M.2 SSD Combo (NVMe PCIe Gen3 / SATA ). By "technicalities" we do not know how the PCIe routing is done (caveat emptor!), and there may be limited routing and support for the interface. Just to mention, Magician will also inform if the driver is Windows or Samsung's, and the PCIe allocation and interface type.



As for the issue, you cannot expect that since you have the 970 and its write speed is capable of XGB/s that it will equal the performance, or better. Now, the main considering aspect of your performance is due to you having a laptop with many thermal and power saving features implemented (enabled). With desktops this is very moot and also usually an issue because of motherboard EFI configuration code implemented-which many Linux users know about; and why many times it [LSPM / ASPM] is disabled to those that know via Power Configuration.

I would consider your power profiles and PCIe configuration settings with Window's Power Configuration, and also check the driver because it can be a generic and not the provided driver from Samsung. However, if the device is OEM then there will only be the driver provided by Windows NVMe. There was a known issue, possibly resolved, when a power feature cause lesser performance back in the 960 days using the generic NVMe.

Also, toggle to disable the Windows write buffer cache flushing in Device Manager. This always should be toggled to prevent flushing of the buffer.

One last thing is the mitigation updates did affect the performance of I/O with this generation, and should also be considered in the overall performance. There personally was a difference with my 6700K/Z170 with SATA and NVMe.
Sorry. I have not kept up with the mobile chipsets, especially since I never owned a laptop that's newer than Haswell.

It boils down to the thermal performance itself. It is very likely that the low write speeds are due to the SSD running too hot. And once the m.2 PCI-E SSD reaches its maximum temperature limit, the interface will slow down - perhaps to as little as PCI-E 1.0 x1.

Thus, it is highly likely, though not certain, that the OP's SSD is overheating.
 
Dunno, NVMe controller thermals can have a factor. But I think it has more to do with a few particular factors. Such being, NVMe thermals, thermals settings, LSPM, ASPM, and a combo of driver and other settings. That is the issues with laptops-they like wireless are convenient. Not actually performance capable of a desktop. There are a few variables....
 
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