Avoid AMD AHCI driver at all costs

perdomot · 06-16-2010, 11:38 AM

I had thought my AMD rig was moving slower than before even with my new SSD in place so I did some testing and found out that the AMD driver for my 785G mobos AHCI mode was killing performance, especially my WD HDD. I changed back to the MS AHCI driver and the numbers are much better. Curious if the Intel AHCI drivers can be used on an AMD rig and would they result in even better results. I posted the two before and two after ATTO benchies on Flicker for review:
http://www.flickr.com/photos/logan66...7624288866056/

shortylickens · 06-16-2010, 11:44 AM

I thought AHCI was something I just selected in my BIOS and that was it.
Will I also have to download special drivers in Win7? Or will it be found and retrieved automatically with Windows Update?

perdomot · 06-16-2010, 02:32 PM

Win 7 has its AHCI drivers that install automatically and they are better at performance but don't allow for hotswapping.

lopri · 06-16-2010, 02:40 PM

Quote:

Originally Posted by perdomot

Win 7 has its AHCI drivers that install automatically and they are better at performance but don't allow for hotswapping.

?

lopri · 06-16-2010, 02:46 PM

I remember somewhere that hotswap icon disappears when Win7 is installed on an SSD, though.

mfenn · 06-16-2010, 03:43 PM

Quote:

Originally Posted by lopri

I remember somewhere that hotswap icon disappears when Win7 is installed on an SSD, though.

Nope

coolVariable · 06-16-2010, 04:42 PM

Quote:

Originally Posted by perdomot

I had thought my AMD rig was moving slower than before even with my new SSD in place so I did some testing and found out that the AMD driver for my 785G mobos AHCI mode was killing performance, especially my WD HDD. I changed back to the MS AHCI driver and the numbers are much better. Curious if the Intel AHCI drivers can be used on an AMD rig and would they result in even better results. I posted the two before and two after ATTO benchies on Flicker for review:
http://www.flickr.com/photos/logan66...7624288866056/

Yes - there used to be a thread on the AMD/ATI forums though nothing ever came out of it.
The MS AHCI drivers CAN (don't have to) result in stuttering performance though (e.g. Win7MC Live TV will stutter)

Auric · 06-16-2010, 05:27 PM

MS driver shows eject but does not automatically detect a new drive. Intel driver does not show that eject (perhaps through RST for H57/Q57 though) but does automatically detect a new drive. Third-party HotSwap! utility works around both boners.

ElFenix · 06-16-2010, 05:38 PM

Quote:

Originally Posted by Auric

MS driver shows eject but does not automatically detect a new drive. Intel driver does not show that eject (perhaps through RST for H57/Q57 though) but does automatically detect a new drive. Third-party HotSwap! utility works around both boners.

so that's why i have trouble trying to use my eSATA box

coolVariable · 06-16-2010, 08:53 PM

would be nice if the bad performance got some more attention (e.g. an Anandtech article).
This is a known issue for at least 1 1/2 years now with no fix in sight.

perdomot · 06-17-2010, 12:13 AM

Yeah, I was reading this article when the write speeds of the HDD caught my eye:
http://www.techreport.com/articles.x/18539/8
My write speeds were about 30MB/s off from what they were supposed to be and when I changed my driver from the AMD one to MS, everything jumped back to normal. I wonder if the newer 8XX series ahci driver is any better and can even be used by 785G mobos.

perdomot · 06-17-2010, 12:16 AM

To lopri and mfenn,
How do you get those eject lists to come up? Where are they at in Windows?

thescreensavers · 06-17-2010, 12:27 AM

Ok cool, going to put together a rig this week with the 785g mobo thanks for the heads up.

sub.mesa · 06-17-2010, 01:15 AM

Don't you guys just get slower speeds because with AMD driver you do not have TRIM capability? It's not like AHCI should influence sequential speeds anyway.

perdomot · 06-17-2010, 11:05 AM

Well in my case, my mechanical hdd noticed a more than 30MB/s increase in write speeds just like in the above article where the H55 chipset beat the AMD solution on sata write speeds. With my ssd, the read speeds increased, most significantly starting with the 16.0 test and throughout the rest of the test. The system also feels more responsive but that is a subjective opinion. The most important thing I see is that if you are using a mechanical hdd as most people are and are going to make a Win 7/AMD rig, only use the MS drivers that come with Win 7.

RebateMonger · 06-17-2010, 11:15 AM

Quote:

Originally Posted by coolVariable

The MS AHCI drivers CAN (don't have to) result in stuttering performance though (e.g. Win7MC Live TV will stutter)

My brand-new Win7 install, using a full Intel chipset (P45) and ICH10R disk controller and a 320 GB WD SATA drive, was useless with the default MS AHCI driver. I'd click on an icon and it'd take 30 seconds before I could do anything else. As soon as I "updated" the driver to the Intel AHCI, it worked perfectly.

tcsenter · 06-17-2010, 11:39 AM

Intel's storage driver performance doesn't suck. AMD's does, as has been documented pretty well. Even its RAID performance, though better than its AHCI, lags behind Intel.

coolVariable · 06-17-2010, 01:38 PM

So the verdict is: don't buy AMD?

lopri · 06-17-2010, 08:14 PM

Quote:

Originally Posted by perdomot

To lopri and mfenn,
How do you get those eject lists to come up? Where are they at in Windows?

They just show up after the OS installation in AHCI mode. Bottom-right corner of the task bar (notification area).

perdomot · 06-18-2010, 12:36 AM

Quote:

Originally Posted by coolVariable

So the verdict is: don't buy AMD?

On the contrary, AMD is excellent except their ahci driver. As long as you are using the Win 7 default ahci driver, you're fine.

perdomot · 06-18-2010, 12:38 AM

Quote:

Originally Posted by lopri

They just show up after the OS installation in AHCI mode. Bottom-right corner of the task bar (notification area).

Damn, I can't find mine and there is no icon in the notification area for that. What could be wrong?

coolVariable · 06-18-2010, 02:39 AM

Quote:

Originally Posted by perdomot

On the contrary, AMD is excellent except their ahci driver. As long as you are using the Win 7 default ahci driver, you're fine.

THAT is not true! The stuttering in Windows Media Center with the MS AHCI driver is evidence enough that there is some issue!!
I would have loved to know this 1 year ago when I upgraded my media center/server/desktop - I would have NOT bought an AMD.

DON'T BUY AMD UNTIL THEY FIX THIS!

tcsenter · 06-18-2010, 02:43 AM

You can use RAID mode with the RAID driver, just don't create a RAID volume (i.e. non-RAID disk). I prefer this to AHCI on AMD because it works, performance is better (though still not up to Intel), and you get all the enhanced features such as NCQ. Only caveat is, if you are using an SSD, you don't get TRIM support on Windows 7 in RAID mode.

I would like to see an Anandtech write-up article on AMD's piss-poor AHCI driver implementation? Maybe that would go a longer way towards getting AMD to take notice and do something. Its been an issue now for well over a year, going back to the first SB750 boards.

Marlin1975 · 06-18-2010, 07:47 AM

Which one are you using. AMD has a new AHCI and Southbridge driver (Version 10.6) that came out June 16 (couple days ago)

http://game.amd.com/us-en/drivers_ca...ista32-chipset

taltamir · 06-18-2010, 11:34 AM

Quote:

Originally Posted by coolVariable

DON'T BUY AMD UNTIL THEY FIX THIS!

Or run AMD drives in legacy mode (called IDE stupidly enough by mobos... even though its not IDE, its just legacy ATA)

Keep in mind that AMD is a budget oriented company, for people who can't afford the quality of intel. Having things not work right is expected.