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AHCI mode

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My old PC uses IDE mode by default, but supports AHCI, but it is not enough to just switch mode in the BIOS.

I can install in AHCI mode and then switch back to IDE... the problem is when I then switch back to AHCI... I can't boot.
 
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same problem when switching from ahci to raid but can do the reverse even if you install the driver sadly
 
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OK, I stay on IDE

Hopefully the SSD will TRIM itself.
 

bug

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I don't understand your problem. Switch to AHCI, install, never look back. No problem.
 
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The default is IDE, so if the CMOS battery runs down, I'm back in IDE mode.
 
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Since I had my own desktop computers from 2006 till now, I never replaced 1 CMOS battery...
 
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And therein lies my problem... I would be in IDE mode and can't easily get back to AHCI
 

bug

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And therein lies my problem... I would be in IDE mode and can't easily get back to AHCI
Get a new CMOS battery if you're worried about that. It will last you longer than the rest of that system will.

Also, when you're back to IDE, Windows won't boot, but it will not corrupt your install. Just go back to BIOS, select AHCI again, reboot.
I know you said in your first post it won't boot after you got back into AHCI mode, but I've never seen that. Are you sure you didn't do/change anything else in the process?
 
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This whole thread is confusing. You say you changed to AHCI, successfully installed, and then switched back to IDE… Why would you switch to IDE after all of that trouble.

And, as others have said, CMOS batteries last forever (I have also never replaced one in 25+ years of pc building) and cost less than $1. If that’s the issue then it’s an easy fix.
 
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It does boot in the move back to IDE, BUT a move back to AHCI has it not booting.

I don't move it back to IDE, the CMOS battery does...

I thought the batteries lasted about 5 years.
 
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Maybe we posted simultaneously but I still don’t understand why you switched back to IDE after installing in AHCI
 
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I mean you can't just manual boot the AHCI drive if still in IDE Mode in BIOS. That's not how it works. Either one way or the other. Depends on the storage but I'd just use IDE as storage. Heck I have a laptop IDE HDD on my 775 build here with WIN7 lol but use it for kicks/giggles. I have WIN11 and WINLTSC on separate drives "M.2 Sata to SSD Enclosure"
 
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Mine is indeed a 775; I put it in AHCI mode in the BIOS and then installed Windows

I am preping for a solid state drive that gets here tomorrow and wanted to know what mode to use; I'll be sticking with IDE

This is my main machine at home, so I take it seriously (I'm doing the experiments on another 775 machine).
 
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Strange, am running two old PC Including the one i'm posting with & I can switch between both modes & it will still boot. Maybe it's important when OS is first installed to be in AHCI mode, because after that it boots in both modes here. ..939 & 938 platform.

Maybe you need to check your on the latest BIOS, because here during boot-up if it's in IDE mode a message will pop-up stating im in IDE mode & it will say do I want to switch to AHCI mode.
 
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Hmm ha I'll double check... :slap:

It is in IDE mode lol but I don't think it'll make a difference really
 
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Much appreciated

Maybe you need to check your on the latest BIOS, because here during boot-up if it's in IDE mode a message will pop-up stating im in IDE mode & it will say do I want to switch to AHCI mode.

Latest BIOS (2015)

I think one has to go ahead with the IDE boot for Windows to redo its drivers.

I'm on Windows 10, in case that makes a difference.
 
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Much appreciated



Latest BIOS (2015)

I think one has to go ahead with the IDE boot for Windows to redo its drivers.

Like I said, I think during OS install including all important updates it must be in AHCI mode. After that it should boot in both modes because battery do die at some point which will reset the BIOS back to default.
 

bug

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Strange, am running two old PC Including the one i'm posting with & I can switch between both modes & it will still boot. Maybe it's important when OS is first installed to be in AHCI mode, because after that it boots in both modes here. ..939 & 938 platform.

Maybe you need to check your on the latest BIOS, because here during boot-up if it's in IDE mode a message will pop-up stating im in IDE mode & it will say do I want to switch to AHCI mode.
That's how I remember it, too: install in IDE mode, you'll always have to boot in IDE mode; install in AHCI mode, you'll always have to boot in AHCI mode.
What I don't remember is accidentally switching modes breaking anything. I was always able to go back to the right mode and boot again.

Keep in mind, in IDE mode, you're limited to 133MB/s. You still get the fast seek times of an SSD, but your transfers will be slow.
 
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  • I moved to AHCI mode (in BIOS) and installed Windows 10: boots
  • I moved back to IDE (in BIOS): boots
  • I moved back to AHCI (in BIOS): no boot

My machine is SATA 2 and I get more than 150 MB/s on my hard drives (IDE mode)
 
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ir_cow

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Since I had my own desktop computers from 2006 till now, I never replaced 1 CMOS battery...
Never had to replace a battery either. I personal know of 1 person who has so far.
 
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  • I moved to AHCI mode (in BIOS) and installed Windows 10: all good
  • I moved back to IDE (in BIOS): all good
  • I moved back to AHCI (in BIOS): no boot

My machine is SATA 2 and I get more than 150 MB/s on my hard drives (IDE mode)

You may have to do a couple of soft reset. It should switch back & boot to AHCI. ..Also make sure time & date are correct & not back to i's default.
 
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It does boot in the move back to IDE, BUT a move back to AHCI has it not booting.

I don't move it back to IDE, the CMOS battery does...

I thought the batteries lasted about 5 years.
Nah they last way longer than 5 years. More like 15 years or more. Among the PCs I still own, I've only had to replace the one on a 20 year old Socket 478 board.

They're like....Game Boy carts.
 
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