Set mobo to AHCI and now drives are much slower...

[Staple]

I just realized that my mobo was set to IDE instead of AHCI. I switched it over and made the required Windows changes and my drive speeds are much slower now...why would this happen?

IDE mode:

Sequential Read (Q= 32,T= 1) : 174.517 MB/s
Sequential Write (Q= 32,T= 1) : 173.800 MB/s
Random Read 4KiB (Q= 32,T= 1) : 0.751 MB/s
Random Write 4KiB (Q= 32,T= 1) : 1.953 MB/s
Sequential Read (T= 1) : 164.210 MB/s
Sequential Write (T= 1) : 161.377 MB/s
Random Read 4KiB (Q= 1,T= 1) : 0.729 MB/s
Random Write 4KiB (Q= 1,T= 1) : 2.076 MB/s

AHCI:

Sequential Read (Q= 32,T= 1) : 103.256 MB/s
Sequential Write (Q= 32,T= 1) : 98.435 MB/s
Random Read 4KiB (Q= 32,T= 1) : 1.944 MB/s
Random Write 4KiB (Q= 32,T= 1) : 1.755 MB/s
Sequential Read (T= 1) : 97.107 MB/s
Sequential Write (T= 1) : 97.938 MB/s
Random Read 4KiB (Q= 1,T= 1) : 0.679 MB/s
Random Write 4KiB (Q= 1,T= 1) : 1.871 MB/s

 

[Coup27]

PC specs, drive specs, OS specs..

I have never personally switched from IDE to AHCI without formatting so I have never experienced this. Is a clean format in AHCI an option for you?

 

[Staple]

PC specs, drive specs, OS specs..

I have never personally switched from IDE to AHCI without formatting so I have never experienced this. Is a clean format in AHCI an option for you?

Gigabyte X58-ud3r with a Core i7 920 overclocked to 3.3GHz. Win 8.1, drive is a WD Blue 1TB.

All my drivers and BIOS are up to date.

 

[bradly1101]

Are you using the Intel-provided driver or the Windows one?

 

[Staple]

Are you using the Intel-provided driver or the Windows one?

I originally used the Windows one and then updated to the latest Intel driver. The Intel driver did increase speeds by maybe 10% but still nowhere near my original IDE speeds.

 

[bradly1101]

Hmmm. I looked around the 'net to find others with this problem and couldn't find any, just the Registry change, etc. The benches I saw showed the opposite. Hmmm.

 

[Staple]

Hmmm. I looked around the 'net to find others with this problem and couldn't find any, just the Registry change, etc. The benches I saw showed the opposite. Hmmm.

I know that's what I've found too.

I can't figure it out. IDE gives me a boost of about 50% as you can see from my numbers and nothing seems to change that.

I did see a couple of mentions of similar issues but no one seemed to solve it.

 

[Ketchup]

For a hard drive, I don't really see the need to stay with (what is in your case) the slower setting. Run faster in IDE mode? Let's leave it there!

SSDs are the ones that get the most benefit from AHCI, and there are several discussions as to whether THEY even see a significant speed benefit from using AHCI.

 

[VirtualLarry]

Could it be some sort of interface power-management setting that's native to AHCI mode but not IDE? That could slow things down.

 

[Staple]

For a hard drive, I don't really see the need to stay with (what is in your case) the slower setting. Run faster in IDE mode? Let's leave it there!

SSDs are the ones that get the most benefit from AHCI, and there are several discussions as to whether THEY even see a significant speed benefit from using AHCI.

AHCI allows hot swapping of drives which is why I wanted to keep it...very convenient for removable storage bay/backups. Otherwise I'd probably just go back to IDE. Although it is puzzling regardless.

 

[Staple]

Could it be some sort of interface power-management setting that's native to AHCI mode but not IDE? That could slow things down.

Any idea where I'd find such a thing? I've searched the BIOS settings along with the device manager etc. but nothing seems to make any difference.

 

[Engineer]

Which SATA port do you have the drive attached to?

(Note: There are two SATA systems on your board - one via Intel and another (not sure which brand))

 

[Staple]

Which SATA port do you have the drive attached to?

(Note: There are two SATA systems on your board - one via Intel and another (not sure which brand))

It's the Intel one...I've also tried others without change. It worked fine just minutes before switching to AHCI so I doubt that's it but I did give it a try.

 

[Staple]

Well, I've about given up on figuring this one out...I've not been able to make any progress as to why AHCI would cause such a drastic drop in performance.

 

[john3850]

How much free space is left on your hd.
After my two year old Adata ssd died I replaced it with a M-4 128GB on 05/14/2013 on a i7-930.
SATA2 using a msahci controller with 93GB of free space.

ASSSD Bench
------------------------------
Sequential:
Read: 269.38 MB/s
Write: 181.40 MB/s

------------------------------
4K:
Read: 25.26 MB/s
Write: 54.08 MB/s

 

[Staple]

How much free space is left on your hd.
After my two year old Adata ssd died I replaced it with a M-4 128GB on 05/14/2013 on a i7-930.
SATA2 using a msahci controller with 93GB of free space.

ASSSD Bench
------------------------------
Sequential:
Read: 269.38 MB/s
Write: 181.40 MB/s

------------------------------
4K:
Read: 25.26 MB/s
Write: 54.08 MB/s

About 40% free space so about 400Gb.

 

[blankslate]

If I recall correctly an SSD guide recommended making sure the bios is set to AHCI before installing your OS as having it in the legacy or IDE mode and installing the OS then setting it to AHCI later could cause issues with some system configurations.


____________________

 

[tcsenter]

I just realized that my mobo was set to IDE instead of AHCI. I switched it over and made the required Windows changes and my drive speeds are much slower now...why would this happen?

Using what benchmark utility?