Wrong, is has to split that data onto all of the disks, and reverse for reeding no? So there is at least a bit of work…
I am not sure, but bifurcation do not work on all slots, and maybe just on one? And you have several cards…
I agree that there is definitely some overhead for splitting the data for writing and reading, but I don’t think it would be significant, but I could certainly be wrong.
My motherboard has 4 slots with dedicated 8x PCIe lanes directly to the CPU, for a total of 32 lanes. 2 slots share one 16 channel port, and the other 2 slots share the 2nd 16 channel port. Bifurcation has been enabled on both 16 channel ports, feeding the 4 slots. The remaining 8 lanes are split between 2 more slots and various other I/O functions of the mobo.
I posted up more details over on another forum. Not sure if I’m allowed to link to it, but here goes:
https://hardforum.com/threads/pcie-bifur…post-1044652089
It shows the Crystal benchmarks I’m getting for the various combinations, the block diagram of my mobo, bifurcation settings, etc.
This one really got me stumped…
I stand corrected. I side graded from a E5-2683 v3 (14 cores @ 2Ghz) to a E5-2680 v3 (12 cores @ 2.5GHz) and I’m now seeing 10GB/s writes and just shy of 7GB/s on writes. Still odd that CPU utilization during benchmarks barely registered anything. Anyway, sorry for going off topic since this clearly is not driver related.
Told you, it is CPU bound when software RAID…
And it is normal for low utilization, that is not the issue here; but explaining would be quite long a heavily off-topic 
One final note I’ll make is that when I’m running the benchmarks (be it ATTO or Crystal) those are single threaded apps and on my 12 core/24 thread CPU, only a single thread is maxed out with the remaining 23 threads are idle. So that explains why I was only seeing 4% utilization when looking at the overall load. I suspect the crux of the issue is that synthetic benchmarks like these are single threaded in nature and are not able to utilize multiple threads. The good news is that these servers, as nodes in a storage spaces direct cluster, will not exhibit this single threaded restriction VMs are accessing the data store that will live on the NVMe storage.
@Fernando
With the help of Microsoft Technical Support level2 we have investigate the root cause of reproductible and sytematic BSODs observed after each shutdown PC, or restart PC when W10 20H1 is booted of Intel NVMe SSD i750 device.
Clearly it has proved when analysis of BSODs dumps that Intel NVMe drivers are NOT working properly when shutting down or restarting PC.
The problem does occur with Intel NVMe drivers whatever the vesrion used (v3.2.0.1002 or v4.4.0.1003 or v5.5.0.1360 or v6.3.0.1022).
The only workaround is to use native W10 NVMe driver.
Anyone know of any generic AHCI drivers for Vista x64? I’m having issues that might be related to the storage driver on my system
@asdf23451 :
If you are searching for an alternative AHCI driver, you should let us know the manufacturer and the model/DeviceID of your on- board SATA AHCI Controller.
@Fernando :
The reason I’m looking for AHCI drivers, is that the generic Vista AHCI drivers might be somewhat incompatible with my system. I get random 0x0000007B startup errors sometimes, I get random crashes Bad_Pool_Header, Bad_Pool_Caller, IRQL_Not_Less_Or_Equal, and a couple of times I’ve had Vista freeze up like I just unplugged the SSD it’s installed on.
The hardware ID is PCI\VEN_1022&DEV_7901&CC_010601 (Also PCI\VEN_1022&DEV_7901&SUBSYS_7B781462&REV_51). I’ve found some Windows 7 SATA drivers from 29/3/2015 with the versioning 1.2.1.402 specifically for this SATA controller. (They were already installed on my Windows 7 install) I tried installing it onto Vista after modding it, and everything seemed fine, until I had two System_Service_Exception 0x0000003B bluescreens, and now Vista doesn’t boot, after selecting it in Windows boot manager, it goes to a black screen. I have OS boot information enabled, so I should see it start to load some files, but I don’t see it loading anything
I’ll try installing Vista again, as that install was a modded install I made. I misplaced the disks, so i installed the modded copy by accident.
I have some minidumps, and I’ve already done some troubleshooting, the links below will give you more info.
https://msfn.org/board/topic/177576-comp…comment-1184551
https://msfn.org/board/topic/181709-vist…often-on-2700x/
I’ll be installing Vista on as stable of a system I can make, meaning I’ll reduce my RAM to 16GB, running at 2133MHz auto, underclock my CPU, and disable 1 CCX, install the SATA drivers from the Vista setup, and use a different SSD plugged into a different SATA port.
If this doesn’t work, I’ll have to see if you have any other SATA drivers I could try
There’s a delay in my plans, Windows is being Windows, and is causing issues when I’m trying to clear out my other SSD to make a 64GB partition for Vista
@asdf23451 :
If you want to do a fresh install of Vista x64, but avoid the usage of the in-box MS AHCI driver, I recommend to load at the beginning of the OS installation the "64bit AMD AHCI Driver v1.2.1.402 WHQL for Win7 x64", which I am offering within the start post of this thread. AFAIK it supports the OS Vista x64 as well and your on-board AMD SATA AHCI Controller DEV_7901.
A compatible 3rd party generic AHCI driver is neither available nor usable while doing a fresh install of the OS.
You should better use one of the available 3rd party Partition Tools.
Messaged me right as I was about to finally begin installation, I will get those drivers, and see why my PC isn’t detecting either of my SATA SSDs
@Fernando :
I found you made a 1.2.1.321 driver that supports my controller, and is pre-modded to work on Vista. Should I use that instead, or go with the 402 driver?
I also got my SATA working again. I reconfigured it, but got confused and plugged one SATA port on my board into another
@asdf23451 :
Try the attached driver. It may work with Vista x64.
64bit AMD AHCI driver v1.3.1.276.rar (135 KB)
Was about to try installing Vista over USB, I was at the drive selection screen when you replied
I’ll try that driver, then if it doesn’t work, I’ll try USB
Doesn’t show up in setup either
@asdf23451 :
What doesn’t show up? Since Vista has a generic MS AHCI driver in-the-box, all HDDs/SSDs, which are connected with any AMD SATA port, should be detected by the Setup.
You should unzip the driver files onto an USB stick and navigate to it while trying to install the OS.
@Fernando :
Will have to try that, can’t install though USB according to Windows setup
When I point to the driver, Windows scans for it, and I believe it detects it, but it doesn’t show up in the list of drivers to install. I believe it detects it, because I don’t get a driver not found message when pointing to the folder the driver is in