AHCI vs IDE - Page 3

Since this thread was found via google, ...
just here to report some differences between AHCI vs IDE on win 7 64bit (using MS drivers which means TRIM is on)
Using Intel x25-m 80GB (G2),
on AHCI, Intel Toolbox doesn't allow you to run Intel SSD Optimizer (but it's ok, since OS does TRIM, you won't need to - I'd say; after a month or more I switched back to IDE so I could run it and it finished in a second as always - if there was a need to run it(meaning TRIM didn't work?), it would've prolly taken minutes)


On IDE, this is HDTune results with Intel X25-m 80G (G2):

as you can see above, the fourth core is 100% used (25% cpu usage reported since it's 4 core cpu), and ssd speed depends on the CPU speed, ie. lower CPU speed (ie. by limiting it via Power Options) means lower ssd transfer speeds(if you don't believe me ask and I'll post some screenies). The fourth core is actually used 100% due to Interrupts (as reported in Process Explorer).



Now, on AHCI, this is HDTune results with Intel X25-m 80G (G2):

as you see here, higher transfer speed and lower cpu usage(5% vs 26%) with AHCI


So, for me, AHCI for the win.

EDIT: intel x25-m 80g Postville 34nm 2.5" (INTEL SSDSA2M080G2GC) revision: 2CV102HD on sata2; Controller TypeIntel PC29AS21BA0
and switching between IDE and AHCI (while windows was installed when ssd was on IDE - because due to a bios bug AHCI bios would freeze, so I had to update bios later to be able to use AHCI at all) was possible by only reboot and changing the bios setting: from IDE to AHCI and reverse (no need to reinstall anything; in my case anyways)
MOBO: Gigabyte GA-MA790FXT-UD5P
CPU: Phenom II X4 965 rev.RB-C2
OS: Win 7 64bit
mem: 4x2GB DDR3 Unganged, Dual Ch.
Edited by joojooo - 8/21/11 at 11:25pm

hmm... interesting topic, i was just debating to stay on IDE or go AHCI, having to re-install the whole OS again

it seems the results indicates it's worth the trouble of doing a clean install to use AHCI

You don't have to reinstall.

http://www.neowin.net/news/neowin-guide-how-to-change-from-ide-to-ahci-without-reinstalling-windows

Done it before a long time ago, works perfectly.

Thanks, but no, i was not thinking about the Windows driver issues

Rather, I've already tried booting it off AHCI, and it wouldn't detect the SSD (OCZ Vertex 4 256MB), and it only sees them as boot-able if i set them as IDE in the BIOS
which is rather weird.

if i set the BIOS to AHCI and try to boot from the SSD, it just completely ignores there's a drive there, it's as if the SATA3 controller X79 doesn't even see it

still trying to figure out why.

When you want to install your OS, take out all other drives. Leave the SSD plugged, Secure Erase it if it has data. Set AHCI in the bios and install Windows, easy.

If you can't do the above, then your drive is faulty (or something is clearly malfunctioning) and you should head to OCZ forums and bug them about it. Not much you can do that I can think of besides updating BIOS or SSD Firmware.

Getting a last gen to be detected in AHCI should be a basic thing...

update.

so in the end it was neither the drive, or IDE / AHCI setting

it was the BIOS being stupid and did not see the proper boot order of the HDDs in the rig

2x OCZ Vertex 4 256MB
5x Seagate Barracuda 3TB

so instead of following what was indicated and set in the BIOS to only boot from any of the 2 SSD
the BIOS still tried to read from the 3TB Barracudas that were formatted using GPT and of course those are not bootable

didn't help at all to reset the settings in the BIOS

the solution that worked, but doesn't make any sense is, by hot-swap un-pluging / re-pluging the SATA drives in the order you want them to boot

then the dumb BIOS keeps those undocumented "settings" for some odd logic

so, now even after i power off the machine, and power the rig back up, it keeps the order how i manually plugged in the SATA drives, even if they are out of sequence according to the ports number in the BIOS list or physical MB sata plugs.

Window usually do this auto.if ms was to ask each time this or that you might get infuriated afteer 48 hour

So let me get this straight :you go in bios hdd section?then plug the hd in the order you want them to start?could be wrong here but my guess is you just happened to be in the proper order needed.bios are flexible yes but they arent dynamic.bios is like a 2 year old kid lol

that's exactly why i said, it didn't make any logical sense.

normally you configure within the BIOS which HDD drive to boot from, in this case it was completely ignoring that
instead it picked up the proper order after i unplugged them and plug the boot drive back in first, then it kept the setting

i noticed the last 2 ASUS ROG MB are doing that for some strange reason

when you hit F8 to choose the drive to boot from it shows the TRUE list of drives how the BIOS will boot from
which is always different than the list that you have configured inside the BIOS in the HDD boot order screen.