Judge584
Silver

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Hi Justin,

Unfortunately it will not solve the problem : write-cache buffer is already deactivated on my xps9360.

By the way I suggest you to also test latest IRST drivers from Intel (v15.8.1.1007), as they provide a little performance improvement over Dell's one and even better : they do reduce coil whine greatly when SSD is under stress with latest 2.4.2 BIOS ;-)

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Moderator
Moderator

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Hi Judge584,

I assumed it wouldn't solve it, just doing my due diligence Smiley Happy

I'm running on 15.7.5.1025 WIN10 with write-cache buffer set to off. I have maintained replication of the performance numbers, as we expected. Below is my latest test:

I will test out 15.8.1.1007 to see what happens.

Justin C

Dell Technical Support L3 | Project Sputnik

Dell Support is also on Twitter! https://twitter.com/DellCaresPRO

 

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brihi7577
Copper

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

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.Chris._
Copper

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Just got a 7577 with 256GB NVME and 1TB Hard Drive. Took out the hard drive and replaced it with my 1TB Samsung 840 evo SSD. The Samsung Magician software wasn't fully functional and saw that the bios was set to raid and not AHCI. Are there any long term performance or reliability reasons that I should switch over to AHCI from the raid? I'll just leave it as is if there shouldn't be any issues.

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Judge584
Silver

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Hi Justin, I have news: please find below latest tests results

Config : XPS 13 9360 i5-8250u 8GB ram and with Toshiba XG5 256GB PCIE-Nvme

Bios: 2.4.2

Bios mode : RAID

IRST Drivers : latest from Intel website : version 15.8.1.1007

First run after windows boot :

Second run 1 second after first one :

Third run 5 minutes after second run:

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Moderator
Moderator

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

@Judge584,

Thank you for your testing and feedback. I did more replication attempts yesterday as well and I've consistently re-produced the behavior, including on 15.8.1.1007. The drive is going to Dell engineering at this point.

My next step is to simply wait for engineering to get back with me on why this drive is performing this way. I will be back to delivered any results I obtain in the future. No ETA right now.

Justin C

Dell Technical Support L3 | Project Sputnik

Dell Support is also on Twitter! https://twitter.com/DellCaresPRO

 

summitless
Copper

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Hello, I have the same problem with my write speeds.
Model: Inspiron 7577
Specs: i5-7300HQ, 8GB DDR4

Drive: 256GB Nvme Toshiba KXG50ZNV256G

Bios: 1.2.0 (Latest)

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pasquale_s
Copper

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

Hello, I have the same problem with my write speeds.

Model: XPS 9560

Specs: i7-7700HQ, 8GB DDR4

Drive: 256GB Nvme Toshiba KXG50ZNV256G

Please help :-(

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pasquale_s
Copper

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

ho eseguito un aggiornamento completo di tutto il sistema operativo ma la situazione non è cambiata, anzi a tratti è peggiorata. Quando si fa click sull'icona della rete Wi-Fi Windows 10 va in Blue screen!!! Rivoglio i miei soldi!!!

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Moderator
Moderator

RE: Dell M.2 FAQ regarding AHCI vs RAID ON, Storage Drivers, M.2 Lanes, Performance and more

@Community,

Regarding the: 256GB Nvme Toshiba KXG50ZNV256G

Dell's engineering team has advised me that the drive's performance behavior is 'working as designed'. The behavior is due to a drive feature called the "SLC buffer". More on that in this wikiIn the case of Toshiba XG5 256GB, the SLC buffer size is maximized at 1/3 the full capacity of the SSD.

Justin C

Dell Technical Support L3 | Project Sputnik

Dell Support is also on Twitter! https://twitter.com/DellCaresPRO