Fresh install of Win 7, AHCI

[SpeckledJim]

I'm about to switch to the RTM, since I have 6 days left before the RC starts shutting down every 2 hours. I was going to enable AHCI mode, but reading about it here and elsewhere there seem to be a lot of issues with it. Is it worth enabling, or would I be seeing no real improvement? Hot plugging seems like the most obvious advantage, but other than being a nice extra, I can't see myself actually needing that particular feature.

[caveman-jim]

AHCI is a good idea. It offers more than just hot plugging, such as native command queuing. On most modern drives and controllers you'll see a nice performance boost vs. IDE emulated mode.

For your situation I recommend doing an inplace upgrade of RC to RTM. This is possible by extracting the Windows 7 disk/iso to folder on your system drive, and running setup from there. When you do so you'll be greeted with an error mesage about version not able to be upgraded; you can fix this by editing one text file. Inside of your extracted setup folder, look in the sources folder for cversion.ini and edit using notepad. The line minbuild=7233.0 needs to be altered to read 7000.0, then save and close the file. Rerun setup and it will allow you to select an in-place upgrade, preserving all your applications and data (although you should do a back before you begin!).

Once setup completes, then you can do the AHCI registry trick to Win7 to use the AHCI driver next time it boots:

enable the AHCI driver in the registry before you change the SATA mode of the boot drive. To do this, follow these steps:

1. Exit all Windows-based programs.
2. Click Start, type regedit in the Start Search box, and then press ENTER.
3. If you receive the User Account Control dialog box, click Continue.
4. Locate and then click one of the following registry subkeys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\IastorV
5. In the right pane, right-click Start in the Name column, and then click Modify.
6. In the Value data box, type 0, and then click OK.
7. On the File menu, click Exit to close Registry Editor.

http://support.microsoft.com/kb/922976

Now you can reboot and get into the BIOS and configure AHCI, load the desktop and let windows finish installing new devices, reboot, install the latest AHCI drivers for your system, reboot one more time, and enjoy.

2 Problems solved without reinstalling the OS and all your applications and data!

[SpeckledJim]

This has come up before, but unfortunately it has to be a fresh install, as I'm moving to 64 bit, and it's going on a different drive. I tested the RC on a spare old 36GB raptor, but for the permanent install I want it on a larger, newer drive. I guess I could have cloned the RC install to the larger drive and then done the in-place upgrade, but the move to 64 bit makes that moot.

I'll give AHCI a shot then, given the situation I don't have much to lose. Worst case I fall back to IDE if it gives me trouble.

[Qualitier]

In my system, the Vista MS AHCI driver resulted slow, but the AMD one (my disk is connected to the SB750 SATA controller) works as expected. To do the swap, I removed two Device Manager devices (the ones whose files were msahci.sys or similar names), rebooted, one of the devices appeared again, and I updated its drivers through the Device Manager directing it to the right folder (a subfolder of the motherboard drivers unzipped). I cannot remember more details but better use the controller's own driver (from Intel, AMD or whatever).

Curiously, under XP the migration from IDE to AHCI was simpler. In both OS's, I benefitted two ports that can be set to IDE while the others from the same controller are in AHCI. A great idea! Under XP you install the mobo drivers and get the AHCI drivers installed while the disk is still in IDE, so that you avoid the typical "cannot boot for lack of disk drivers" problem. In Vista I had to fix the problem of the slow stock Vista driver, installed automaticly.

[TriGGlety]

Funny, I noticed IDE, AHCI, RAID in my BIOS settings last night, and wondered what AHCI was/

Can I select AHCI in BIOS (XP Pro SP3 + 1 SATA HD), and be good to go?

[caveman-jim]

As long as you follow the steps in the MS article I linked, then yes.

[monkeydust]

Funny, I noticed IDE, AHCI, RAID in my BIOS settings last night, and wondered what AHCI was/

Can I select AHCI in BIOS (XP Pro SP3 + 1 SATA HD), and be good to go?

As long as you follow the steps in the MS article I linked, then yes.

When I just changed mine without taking any preparatory steps, my OS would no longer boot up properly.

[Mystik]

i've had the opposite happen to me between IDE and AHCI.

my drives were slower in AHCI mode than with IDE (p35 chipset).

[caveman-jim]

i've had the opposite happen to me between IDE and AHCI.

my drives were slower in AHCI mode than with IDE (p35 chipset).

You're doing it wrong.

[Mystik]

You're doing it wrong.

not sure how that was possible with fresh installs.

using hdtach or hdtune, ahci enabled showed decreased str speed on all my
drives and that's what i care about.

ncq has no benefits to me because i'm not running multiple programs that try
to access the any of my hdds at the same time.

hot swapping has no benefits to me because i don't hot-swap my internal
drives.

for me, ahci has had absolutely no benefits.

[FiggyG]

not sure how that was possible with fresh installs.

using hdtach or hdtune, ahci enabled showed decreased str speed on all my
drives and that's what i care about.

ncq has no benefits to me because i'm not running multiple programs that try
to access the any of my hdds at the same time.

hot swapping has no benefits to me because i don't hot-swap my internal
drives.

for me, ahci has had absolutely no benefits.

Out of curiosity... was it the msachi that comes with Windows or did you download the latest from Intel?

[Mystik]

Out of curiosity... was it the msachi that comes with Windows or did you download the latest from Intel?

latest of intel.

[Mystik]

You're doing it wrong.

I'd still like to know how i'm doing it wrong.

[Mystik]

You're doing it wrong.

Good to know that wisdom is being spread after being told that i'm doing it
wrong with no way of saying the proper way.

[FiggyG]

On my AMD SB600, msahci performs much better than the AMD driver.

[traitoR]

I'd still like to know how i'm doing it wrong.

Here's an interesting post i came across recently. I don't know if it is 100 % accurate but it sounds like he knows what he's talking about and might explain your situation.

http://forums.ncix.com/forums/index.php?mode=showthread&msg_id=2151205&threadid=2151205&forum=103&product_id=50540&msgcount=2&overclockid=0#msg2151205

What those graphs primarily show is that this new TRIM version, while designed to outperform the original series, no longer supports NCQ. This makes these benchmarks look bad, but it's basically irrelevant to workstation use. NCQ generally slows workstation performance (more processing overhead as the controller constantly looks to reorder commands) and should be disabled in a non-server environment. Firmware (and in this case hardware architectures) are tuned for specific target markets, and this is the reason why the 10k Raptor series outperforms (in desktop environments) 15k SCSI/SAS drives which are optimized for server loads and CQ-intense load conditions. SCSI has supported CQ for nearly two decades. NCQ is useful in situations of severe overload, but those types of queue overload on a workstation generally means you need more RAM (or you're defragging your hard drive--which you should never be doing on an SSD device anyway), not a storage device optimized for server use. Application performance, boot times and file scanning etc are the kind of performance benchmarks that are relevant for average users--which NCQ actually degrades. As interesting as benchmark scores are (and I've been collecting tons of results and done this type of testing for > 20 years) the results need to be taken in context.

When I used the first version of this drive, I swapped it into my biz workstation in which I ran a current gen Fujitsu 15k SCSI drive, and the real world performance was basically a wash. I've since moved on to faster and more advanced SSD products like the Crucial M225, but this product is perfect for the consumer and professional market it was intended for. If people are worried about server-style benchmark performance, spend 50% more and get the Indilinx-based products or even more for the Intel ones. These Kingston products have great warranties, nice bundle kits, faster performance than normal users will have ever experienced, and have been designed with the intention of requiring less maintenance (they tend to choose chipsets which do more automatic internal garbage collection vs Indilinx / Intel etc). If you don't want to run command line cleanup utilities, flash your drives firmware (and risk potential device failure if you do it wrong), or use your SSD in a server environment, these are an easy and solid choice.

[Mystik]

Here's an interesting post i came across recently. I don't know if it is 100 % accurate but it sounds like he knows what he's talking about and might explain your situation.

http://forums.ncix.com/forums/index....d=0#msg2151205

Essentially, he's saying what I said previously.

I get no benefits from AHCI or it's "benefits" (NCQ, hotplugging, etc.) because
my system is not a server, does not suffer from "queue overload" and I'm not
running any SSDs.

He says that, in a workstation environment, this can actually be bad because
of overhead.

I've known this already.

I was basically asking that ("what am i doing wrong") because he just hit and
run with a "You're doing it wrong" with no explanation. His post says that, if
I run with AHCI, I should be getting BETTER PERFORMANCE no matter what,
otherwise I'm "doing it wrong."

I just kind of hate it when people do that.

[traitoR]

Essentially, he's saying what I said previously.

I get no benefits from AHCI or it's "benefits" (NCQ, hotplugging, etc.) because
my system is not a server, does not suffer from "queue overload" and I'm not
running any SSDs.

He says that, in a workstation environment, this can actually be bad because
of overhead.

I've known this already.

I was basically asking that ("what am i doing wrong") because he just hit and
run with a "You're doing it wrong" with no explanation. His post says that, if
I run with AHCI, I should be getting BETTER PERFORMANCE no matter what,
otherwise I'm "doing it wrong."

I just kind of hate it when people do that.

Yeah i guess you pretty much said that in so many words, i was just corroberating what you posted, BTW i agree AHCI and the general attitude towards it is off base, people seem to think this is going to do something special for them in a desktop environment. His post just summarized it well i thought.

[FiggyG]

Hm... I'm going to use IDE mode and see what happens

[traitoR]

Hm... I'm going to use IDE mode and see what happens

If you are using an SSD.

Make sure TRIM is working which you want, if your SSD supports it and you use Windows 7, not entirely sure whether or not it works with IDE.

[Mystik]

If you are using an SSD.

Make sure TRIM is working which you want, if your SSD supports it and you use Windows 7, not entirely sure whether or not it works with IDE.

i don't see why an SSD wouldn't work in IDE mode. i think about those
SATA CF (compact flash) adapters and the like.

unless you're talking about TRIM, then i've read that it works both in
IDE mode and in AHCI -- as long as the AHCI drivers you're using
support it (and hardware, of course).

for SSDs, I have seen people gain performance with enabling AHCI.

for me, in my mind:
rotational disk, IDE mode.
SSD, ahci.

but since i probably won't ever go to SSD anytime soon, my system is always
in IDE mode.

[FiggyG]

If you are using an SSD.

Make sure TRIM is working which you want, if your SSD supports it and you use Windows 7, not entirely sure whether or not it works with IDE.

Unfortunately, I do not have an SSD. However, I did notice that when booting into Vista x64, the period of hard disk inactivity is gone and the time to took to reach the log in screen was reduced by about 5 seconds. I'll run HD Tune later with and without AHCI and see if anything else crops up. edit: not noticing much of a difference, turned AHCI back on.

[Road_Runner]

FWIW using mechanical drives upto 100MB/s I found AHCI or IDE gave about the same performance. Maybe if my drives were heavily fragmented NCQ might make a difference, I don't know. In either case drivers can make a big difference especially with IDE.