Dell RAID/IRST vs. AHCI

I need some documentation or advice on when imaging en mass with MECM on whether or not to change the factory RAID/IRST setting to AHCI before the imaging process begins. Dell ships all of it's corp line (Optiplex, Latitude and Precision) with RAID/IRST as the default BIOS setting. The technicians in my group say that in the past RAID configurations with single drives tend to blue screen after about 3 months use. This is coming from their former job a few years ago.

I manage the actual unboxing and imaging process and our engineers insist on us manually changing the BIOS before imaging from the factory IRST to AHCI before we initiate the PXE process. They are insisting on this manual change because they are trying to write a powershell script to make this change on first boot so we don't have to do it manually. As you can imagine if we have large numbers to install, a manual change before imaging can take a considerable amount of time.

What I don't seem to understand is why make this change at all? If Dell ships computers to the world this way, why would we even bother to make our lives more complicated with more scripts that change it to AHCI. I understand there was issues in the past but that was the past and from what I read, IRST is optimal and doesn't cause a blue screen after 3 months now.

It appears to me we are making this more complicated than we need to and I can't find information anywhere on anyone else having to do this nor can I find any current industry documentation that speaks to this.

Can anyone provide me with more information I can use to help move my engineers to understand that this switch is now totally unnecessary (or maybe it is?) so they don't have to write extra scripts and we can expedite getting boxes out the door?

Many thanks!

My group manages several thousand corporate model Dells. We don't change to AHCI on any of them.

Your corporation surely has their reasons so I can only give you a hypothetical answer and what is my personal opinion..

Jeffrow said:

The technicians in my group say that in the past RAID configurations with single drives tend to blue screen after about 3 months use......

Click to expand...

I would disagree on that. Sure, ANY driver can cause an issue but I do not believe it's a blanket truth of IRST. From my experience, using the IRST driver (as long as it's the appropriate one for the hardware) has not proven to be any more unstable than any other driver.

Jeffrow said:

t appears to me we are making this more complicated than we need to and I can't find information anywhere on anyone else having to do this nor can I find any current industry documentation that speaks to this.

Can anyone provide me with more information I can use to help move my engineers to understand that this switch is now totally unnecessary (or maybe it is?) so they don't have to write extra scripts and we can expedite getting boxes out the door?

Click to expand...

You probably won't find any definitive "documentation". It's nothing more than what the corporate IT department chooses to do dependent on the needs of the organization as well as what they feel will make ongoing management of their systems easier. Maybe they feel from a maintenance standpoint going forward, that it's easier not having to deal with IRST, especially in an environment where mixed systems use different irst drivers. In that case, from a maintenance perspective, AHCI does make more sense.

Maybe they have looked beyond Intel's CLAIMS that even on single drive systems IRST helps with power-saving and performance and have run their own tests.

In tests across the web (and my own) this claim about performance does not hold true.
Tests on my newest Optiplex with a gen 3 mobo shows using the MS nvme driver has a slight performance edge over IRST though not enough to make a difference in real life use. I did not run any power consumption tests so can not attest to that claim. I ran similar tests on my secondary storage drives with no benefit one way or the other.
I chose to change to AHCI so I would not have the hassle of installing IRST during a windows install. It is not only enterprise systems Dell defaults to RAID. They do it on their consumer systems too. For any Dell I clean install Windows on, I change to AHCI.

Possibly your corporation has run their own power consumption and performance tests, and found no substantial benefit of IRST. Why add something to a system that provides no added benefit, could cause an issue at some point in the future, and would require additional measures when deploying to different systems. KISS sometimes makes sense.

There are known problems mixing some RST driver versions on the same system, because Windows can "outrank" one driver set ahead of another. The expedient answer is to disable RAID mode, and go AHCI to bypass the mess. But are you going to audit every system that gets serviced (different mobo after HW swap)? That starts to increase the cost of ownership.

IMO it's better off finding a stable RST driver set, and disabling driver updates from any Dell management tools or WU. Some NVME devices may not work without having the RST driver.

Meh, just have the headache and have a defined driver set per model. No conflicts, no confusion.

What is going on with the randoms on your solidigm ?




This corsair mp510 is a much older nvme

SIW2 said:

What is going on with the randoms on your solidigm ?

Click to expand...

Don't know. I'm not sure exactly what I should do. Here's why.

This system came new with an SK Hynix 256 gb drive using IRST. Here's what the reading looked like on that drive. Notice the randoms.

.
I replaced that drive with the 1tb Solidigm, . At the time I wasn't sure how to uninstall IRST on a working system so left the new drive running IRST. That's the first screenshot above. I became ill and never got around to dealing with it until recently, I figured out how to uninstall IRST and default back to MS storage controller driver without a clean install. That's when I took the second screenshot. Randoms were still off.

I found a Solidigm controller driver but haven't installed it. Whether it would improve the randoms I do not know but I don't think so since the original SK Hynix readings were similar.
I really wante to get aways from having to deal with f6 drivers at all and use the MS driver, but I will if that's what it takes to improve these numbers.
@SIW2 If you have any suggestions I would love to hear them. If you do, PM me so we won't interfere further with this thread..

I cannot change option on my laptop. Intel IRST drive always works fine.