Z790 Apex Encore & Crucial T700 M.2 Strange Write speed issues (check my troubleshooting)

[Rodine]

Good evening, 

@Silent_Scone 

@optiman 

My wife and I Have been struggling with a very strange M.2 NVME issue. I have seen on here another member have a similar issue, but did not see posted what the resolution was. 

My Wife's T700 gets very poor write speeds in Crystal Disk Mark.  Around 500mb/s Writes but she gets about 10,500 mb/s Read's 

I removed the t700 from her Rig, and removed the T700 out of our spare Dark Hero Rig. Installed her T700 in the Dark Hero and we get the correct reads and writes both. 12000+ reads and 11000+ writes. 

I installed the T700 from the Dark Hero into my wife's Rig. Same results 10,000 Reads / 500-600 Writes. 

Troubleshooting steps taken:

• Flashed most up to date bios in all Rigs 1503 
• Flashed backup Bios in Wife's Rig to 1503 as well and tried running on the backup bios, no change. 
• Verified the ALT PCIE Switch is in the Auto Position on all RIGS - Check 
• Purchased Third 14900KS - Installed in wife's machine, wondering if there was an issue with the PCIE lanes on her chip. No Change. 
• Verified Both T700's that we own work as advertised speeds in the Dark Hero motherboard back up system - Check
• Ghosted Wife's T700 onto the Dark Hero T700 and the Dark Hero T700 onto Her T700 (Essentially swapped M.2's including all data) No change 

At this point I am leaning towards a faulty motherboard, however before we start the RMA process with Asus and out of concern that there may not be sufficient Z790 Apex Encore stock available to send to us.. (Tried to RMA a spare 14900K and received an email from intel that they want to send me a 13900K instead.... )  I wanted to post our journey here to discuss. 

mine: 

• Z790 Apex Encore
• i9 14900KS
• Corsair HX1200i PSU 
• Corsair Titanium DDR5 @ 8200 
• Crucial T705 Gen5 2TB 
• Samsung 990 Pro 4TB (spare drive) 
• Asus Strix RTX4090 
• Corsair ICUE Link 420mm AIO  w/ Pump VRM fan (LCD as spare) 
• Thermal right CPU Contact Frame
• Acer Predator X38S  
• Corsair 7000D Airflow RGB 

Wife's: 

• Z790 Apex Encore
• i9 14900KS 
• Corsair HX1000i PSU 
• Crucial T700 2TB Gen5 
• Asus Tuff RTX4090 
• Corsair ICUE Link 360mm AIO - Pump LCD 
• Corsair Titanium DDR5 @ 8200 
• Corsair 5000D Airflow RGB 
• Alienware 38" AW3821DW

Backup System:

• Z790 Dark Hero 
• i9 14900K 
• Corsair Titanium DDR5 @ 7200 
• Crucial T700 2TB Gen5 
• MSI MEG1300 PSU 
• Corsair H150i Elite LCD XT 360mm 
• Antec F1  Case 

[optiman]

The only thing I do not see to try is to force that M2.1 slot to run at GEN5 in the bios and not leave it on AUTO.  That being said, you shouldn't have to do this.

I would rma the motherboard, as you have already swapped memory, cpu, confirmed bios, confirmed the switch at the bottom of the Apex mb is in auto and yet your T700 NVME is only running at GEN4 speeds.  You and me have the same hardware and my T700 is running at GEN5 and speeds prove that.

[Rodine]

My bad, 

PCIE BIFURCATION: M.2 with GPU 

M2.2_1 PCIE : manually selected gen 5 - same results as AUTO 

[JohnAb]

Have you checked that write caching is enabled for the drive on your wife's machine? I got an external Thunderbolt SSD with terrible write speeds until I enabled that. I know your drive is internal, so probably already enabled on both machines, but worth checking.   

[Rodine]

Thanks for the suggestion 

yes, Verified when installing the newest Micron Nvme Storage Controller driver 

[achugh]

Hi @Rodine where did you get this Storage Controller Driver? I am using Corsair CSSD-F2000GBMP700PNH M.2 2 TB drive in my M.2_1 slot on Z790 Dark Hero. When installing Windows 11 Pro fresh I did not install any software for this drive as none is available on the product page at https://www.corsair.com/us/en/p/data-storage/cssd-f2000gbmp700pnh/mp700-pro-2tb-pcie-gen5-x4-nvme-2-... so I am curious what drive software are you talking about here?

I always read and thought that the default Windows drivers are best for NVMe drives over anything else for consumer boards with consumer usage.

[Rodine]

https://www.crucial.com/support/ssd-support/t700-support

[achugh]

Hi @Rodine thank you for sharing this link.

I see the following information on this page that aligns with what I shared here, you DO NOT need this software.

---

The NVMe drivers included with Windows are sufficient for most desktop users. Installation of this optional driver is primarily useful for troubleshooting SSD performance, or for certain Storage Executive functions.

---

Have you tried a fresh Windows 11 installation without installing this driver?

You may also benefit by giving the PCI Express Power Option configuration a try i.e. see if https://www.crucial.com/support/articles-faq-ssd/ssd-used-to-be-faster-but-has-slowed-down helps resolves your issue.

[Rodine]

I installed the newer Micron NVME driver as a troubleshooting step in an attempt to resolve the issue. 

Yes, High Performance Power plan was selected upon windows installation. I always select High Performance on all my builds. 

[Silent_Scone]

@Rodine 

Can you confirm the transfer speeds when the drive is in M.2_2 @ Gen 4.0, please?