I have V-NAND driver for SSDs and M.2 drive and Marvel driver- it is a card- I wish I did not install it but I did- it is PCIe Card with Extra SATA ports and it has driver I had to download from Startech web site- Marvel. I see Marvel under device mamager but when I disable it, nothing changes. The storport.sys is related to RAID and SCSI adopters which I dont have, unless it is Marvel. I have Samsung SSDs. The Seagate and Western Digital hard drives dont require driver. Is there a way to disable storport.sys? Thank you.  

Pull the Marvel SATA controller card (completely out)... and see if it has any affect.

vladasyn
What you mean by "Try SATA only"? I have 1TB Samsung Evo 960 M.2 drive, this is high performance drive that cost $450 just for the drive. It has
Max Sequential ReadUp to 3200 MBps
Max Sequential Write Up to 1900 MBpsM.2 has something like 10GB/sec as opposite to 6Gb/sec of regular SATA SSD. Also it can run in PCIE and SATA mode, I am not sure what is for what perpose. But I know that if ran in SATA mode, it disables some SATA drives and I have all 6 drives taken. "When the M.2_1 Socket 3 is operating in SATA mode, SATA port 1 will be disabled.". I have drive in port one this means it runs in PCIEx4 mode. I have no idea. I also have Marvel controller card in PCIeX4 and this is actually the port I supposed to put Thunderbolt in. 

What I meant was can you exclude the PCIe drive connection and run your system with only drives attached on the native SATA 3.0 ports on the motherboard?
 
I wasn't saying the M.2 drive was your problem, only to entertain the thought that it might be when using the high speed PCIe mode.  It won't matter if you have the fastest CPU and drives on the planet, if the storage drivers involved are making excessive demands on your CPU (DPC latency), it will drop audio buffers on your interface ...pops ...clicks ...etc.

vladasyn
I have V-NAND driver for SSDs and M.2 drive and Marvel driver- it is a card- I wish I did not install it but I did- it is PCIe Card with Extra SATA ports and it has driver I had to download from Startech web site- Marvel. I see Marvel under device mamager but when I disable it, nothing changes. The storport.sys is related to RAID and SCSI adopters which I dont have, unless it is Marvel. I have Samsung SSDs. The Seagate and Western Digital hard drives dont require driver. Is there a way to disable storport.sys? Thank you. 

So, do you have Samsung driver and if yes which version? Mentioned by me thread has the report 2.1 was problematic (with storport.sys showing in LatencyMon). From the changelog, 2.2 can also be not good.


Your conclusions about storport.sys probably comes from the description on MS site... Even I periodically have hard time to interpret these "short descriptions" correctly
 

abacab
 
What I meant was can you exclude the PCIe drive connection and run your system with only drives attached on the native SATA 3.0 ports on the motherboard?
 
I wasn't saying the M.2 drive was your problem, only to entertain the thought that it might be when using the high speed PCIe mode.  It won't matter if you have the fastest CPU and drives on the planet, if the storage drivers involved are making excessive demands on your CPU (DPC latency), it will drop audio buffers on your interface ...pops ...clicks ...etc.

I can take the Marvel controller card and see what happens. Currently I need it for DVD frive- I dont have any more ports left to connect it. Running all Kontakt libraries from SSDs is almost impossible. 

azslow3

vladasyn
I have V-NAND driver for SSDs and M.2 drive and Marvel driver- it is a card- I wish I did not install it but I did- it is PCIe Card with Extra SATA ports and it has driver I had to download from Startech web site- Marvel. I see Marvel under device mamager but when I disable it, nothing changes. The storport.sys is related to RAID and SCSI adopters which I dont have, unless it is Marvel. I have Samsung SSDs. The Seagate and Western Digital hard drives dont require driver. Is there a way to disable storport.sys? Thank you. 

So, do you have Samsung driver and if yes which version? Mentioned by me thread has the report 2.1 was problematic (with storport.sys showing in LatencyMon). From the changelog, 2.2 can also be not good.


Your conclusions about storport.sys probably comes from the description on MS site... Even I periodically have hard time to interpret these "short descriptions" correctly
 

I dont know how to see the version for VNAND driver. I downloaded it in January 2017. Somebody else had to help me find the link because on Samsung web site it is very hard (for me) to find the drivers link- everything is consumer oriented and has washers, driers, TVs, phones and so on. If you could (please) help me find it again, I can look at the file name and see if it was updated or not. 

Are you using the M.2 Socket 3 on the X270 for the M.2 drive in SATA mode or PCIe mode?
 
I ran across this info:  https://www.lifewire.com/what-is-m2-833453
 
Faster Speeds
 
"While size is of course a factor in developing the new interface, speed of the drives is just as critical. The SATA 3.0 specifications restricted real world bandwidth of a SSD on the drive interface to around 600MB/s, something that many drives have now reached. The SATA 3.2 specifications introduced a new mixed approach for the M.2 interface just like it did with SATA Express. In essence, a new M.2 card can use either the existing SATA 3.0 specifications and be restricted to the 600MB/s or it could instead elect to use PCI-Express that provides a bandwidth of 1GB/s under the current PCI-Express 3.0 standards.
 
Now that 1GB/s speed is for a single PCI-Express lane. It is possible to use multiple lanes and under the M.2 specifications, up to four lanes can be used. Using two lanes would provide 2.0GB/s while four lanes can provide up to 4.0GB/s. With the eventual release of PCI-Express 4.0, these speeds would double.
 
Now not all systems are going to achieve these speeds. The M.2 drive and interface on the computer have to be setup in the same mode. The M.2 interface is designed to use either legacy SATA mode or the newer PCI-Express modes but the drive will pick which one to use. For instance, a M.2 drive designed with SATA legacy mode will be restricted to that 600MB/s speed. Now, the M.2 drive can be compatible with PCI-Express up to 4 lanes (x4) but the computer only uses a two lanes (x2). This would result in maximum speeds of just 2.0GB/s. So to get the most speed possible, you will need to check both what the drive and the computer or motherboard support."
 
But this is what jumped out at me ...
 
Command Modes
 
"For more than a decade, SATA has made storage for computers plug and play. This is thanks to the very simple to use interface but also because of the AHCI (Advanced Host Controller Interface) command structure. This is a way that the computer can communicate instructions with the storage devices. It is built into all of the modern operating systems and thus not require any additional drivers be installed into the operating system when we add new drives. It has worked great but it was developed in the era of hard drives that have a limited ability to process instructions because of the physical nature of the drive heads and platters. A single command queue with 32 commands was sufficient. The problem is that solid state drives can do so much more but are restricted by the AHCI drivers.
To help eliminate this bottleneck and improve performance, the NVMe (Non-Volatile Memory Express) command structure and drivers were developed as a means to eliminate this problem for solid state drives. Rather than using a single command queue, it provides up to 65,536 command queues with up the 65,536 commands per queue. This allows for more parallel processing of the storage read and write requests which will help boost performance over the AHCI command structure.
While this is great, there is a bit of a problem. AHCI is built into all modern operating systems but NVMe is not. In order to get the most potential out of the drives, drivers must be installed on top of the existing operating systems to use this new command mode. That is a problem for many people on older operating systems. Thankfully the M.2 specification allows either of the two modes to be used. This makes adoption of the new interface easier with existing computers and technologies by using the AHCI command structure. Then as this the support for the NVMe command structure gets improved into the software, the same drives can be used with this new command mode. Just be warned that switching between the two modes will require that the drives be reformatted."
 
So I wonder if these additional drivers can be causing the DPC load to increase?

vladasyn
I dont know how to see the version for VNAND driver. I downloaded it in January 2017. Somebody else had to help me find the link because on Samsung web site it is very hard (for me) to find the drivers link- everything is consumer oriented and has washers, driers, TVs, phones and so on. If you could (please) help me find it again, I can look at the file name and see if it was updated or not.

http://www.samsung.com/semiconductor/minisite/ssd/download/tools.html
 
But as suggested in the thread, may be you will have to uninstall it (in installed applications or in the device manager if you see nothing in applications). At least for latency test.

Wow! We are Green!
I updated the Samsung NVME driver- I was on 2.1, there was 2.2, and I have significant improvement in the reading! I did not expect much- in versions history it said- the update improved Virtual Machine integration- I thought- this does not apply to me, but I installed it any way and Storport.sys is not on the list any more. There is now Samsung NVME driver showing up occasionally. Thank you for suggesting to update this driver. I suspected it but did not think to update. 
 
And we are Red again. Like really red. This time it is ndis.sys- Network Driver Identification System and DirectX Graphic Kernel. And NVIDIA Windows Kernel Mode. I updated NVIDIA driver yesterday. Can it be related to the number of monitors connected or use of Display Port? I have 4 monitors, 2 are currently on- I have 2 4K monitors connected (one is off) and 2K is on. It looks like Display port occasionally refreshes and my open tabs jump from one monitor to another. I had the 2k monitor off but had to turn it on because everything jumped there for some reason. Not very crazy about the Display Ports- they have issues. I also have DP KVM switch, but that should not affect the latency, unless it some how triggers system to refresh...
 
Thank you.  
 

I am setting Power Plan to High Performance through "Change Advanced Power Options". When I click on that link, it usually set to Balanced (active). I change it to High Performance. The "Apply" button stays grayed out unless I go and change other setting. So I would change Monitor to 19 minutes. Hit Apply, and Ok. Come back- it is back to Balanced, not High Performance and CPU minimum state is 5%. Why? Is there a way to make it stay at High Performance? Thank you again.