WD AAJS & AAKS different DMA modes ?

[NoobyDoo]

I was using a 640GB AAKS and just got a 320GB AAJS.

With Win7 U 64bit AHCI I noticed that the DMA mode for the AAKS drive was "Multi-Word DMA Mode 2" while that for the AAJS drive was "Ultra DMA Mode 6". Is this right or do I need to do something ?

Device Manager -> IDE ATA/ATAPI Controllers -> ATA Channel 1 -> Properties -> Advanced Settings.

btw : AAM is set to 128 for the AAJS by default.

 

[NoobyDoo]

OK, moved the AAKS from SATAII1 to SATAII4. DMA mode changed to "Ultra DMA Mode 6".

Looks like with Gigabyte P35-DS3L : SATAII0 and SATAII1 will give you "Multi-Word DMA Mode 2" (Bus mastering DMA) while SATAII4 and SATAII5 will give you "Ultra DMA Mode 6".

HDTach transfer rates & random access times remained approx the same, but big diff in CPU utilization :
Ultra DMA Mode 6
Multi-Word DMA Mode 2

Does this sound right ? I'm still a bit confused.

 

[NoobyDoo]

With AHCI disabled, on Win7 U 64bit & WinXP Pro SP3 DMA mode is set to "Ultra DMA Mode 5" on SATAII0.

So what should I settle for ?

 

[Nomgle]

Wow, have a look at this thread - http://forums.anandtech.com/showthread.php?t=2030891 - I have exactly the same crazy issue with my GA-P35C-DS3R !

Can anyone else shed any light on this ?

 

[Voo]

HDTach transfer rates & random access times remained approx the same, but big diff in CPU utilization :

The +-2% for that score, more or less mean you can't say anything if you don't run it several times and get consistent results

 

[Nomgle]

HDTach transfer rates & random access times remained approx the same, but big diff in CPU utilization :
Ultra DMA Mode 6
Multi-Word DMA Mode 2.

As above, both those CPU utilization figures are actually the same - both are within the margin of error.

On the other thread, we've come to the conclusion that it's simply a reporting issue - even though Device Manager is telling you it's Mode 2, it's actually running in Mode 6 as it should be. Your performance figures illustrate this perfectly - if it really was running Mode 2, it would be significantly slower !

 

[Strife21]

I just wanted to say I am having the same exact issue and have the WD AAJS 320gb SATA HDD as well. I am using a EVGA P55 SLI motherboard. If I plug into SATA Port 0 on the motherboard and use ACHI I get Multi-Word DMA Mode 2 listed in Device Manager. If I then switch it to SATA Port 2 I get Ultra DMA Mode 6.

If I switch from ACHI to IDE both ports show as Ultra DMA Mode 5.

I end up with the same hard drive score for the windows performance index (5.9) and similar scores in HD Tach, ATTO and HD Tune in one mode vs. the other. Although I did notice a slight increase in maximum read speed when not on port 0.