AHCI made hard drive performance much worse...

[Silverec]

I recently realized that my BIOS setting was set to IDE instead of AHCI. My mobo is a Gigabyte ud3r x58a rev 1.0.

I switched it to AHCI and now my drive performance has dropped dramatically.

While set to IDE my numbers were as follows in Crystalmark:

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

And now in 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

Why would AHCI cause such a drastic drop in drive performance and what might fix it?

 

[jimmysmitty]

Well performance is normally not determined by IDE or AHCI, AHCI just happens to have newer protocols that can be used to help in some areas, such as TRIM for SSDs.

What driver are you running for the SATA controller? The standard Microsoft driver or the latest Intel AHCI driver from their RST software?

 

[Silverec]

Well performance is normally not determined by IDE or AHCI, AHCI just happens to have newer protocols that can be used to help in some areas, such as TRIM for SSDs.

What driver are you running for the SATA controller? The standard Microsoft driver or the latest Intel AHCI driver from their RST software?

It looks like the standard MS driver. I tried installing the Intel driver but Windows wouldn't let me...is it only for SSDs?

Everywhere I've looked recommends AHCI and it also allows hotswapping which is useful because I use a removable drive for backups.

I just can't figure out what would cause such a drastic drop. I do have the latest mobo drivers and BIOS installed.

 

[jimmysmitty]

https://downloadcenter.intel.com/download/25165/Intel-Rapid-Storage-Technology-Intel-RST-RAID-Driver

Have you tried this driver?

You want the one called SetupRST.zip on the bottom left.

 

[Silverec]

https://downloadcenter.intel.com/download/25165/Intel-Rapid-Storage-Technology-Intel-RST-RAID-Driver

Have you tried this driver?

You want the one called SetupRST.zip on the bottom left.

I just tried and it gives me the message "This platform is not supported". I'm using Win 8.1 64bit. Maybe my mobo is the issue?

 

[jimmysmitty]

No it should work. Intel is pretty good with drivers.

http://www.gigabyte.com/products/product-page.aspx?pid=3449#dl

Doesn't look like Gigabyte has official 8.1 drivers but try the one listed on Gigabytes website.

 

[Silverec]

No it should work. Intel is pretty good with drivers.

http://www.gigabyte.com/products/product-page.aspx?pid=3449#dl

Doesn't look like Gigabyte has official 8.1 drivers but try the one listed on Gigabytes website.

OK, I finally got the new Intel driver installed. Thanks very much for your help. Unfortunately I'm still seeing the same poor numbers.

Any other suggestions?

 

[Silverec]

Any other ideas?

 

[jimmysmitty]

Nothing to be honest. AHCI and IDE should not provide a performance difference, as said it adds in features like TRIM of hot swap capability but performance should be similar. Every review I saw shows IDE and AHCI performing very similarly in all but a handful of tests.

 

[Silverec]

Nothing to be honest. AHCI and IDE should not provide a performance difference, as said it adds in features like TRIM of hot swap capability but performance should be similar. Every review I saw shows IDE and AHCI performing very similarly in all but a handful of tests.

Ya, in theory this shouldn't be happening...I even tried new SATA cables and different ports on the mobo but the numbers are the same.

Really confusing. I found a few other reports of this online but no solution.