WD6400AACS vs WD6400AAKS

l0calh05t

Limp Gawd
Joined
Aug 12, 2008
Messages
128
Except for the lower power consumption (and very slightly higher price) of the AACS, what are the differences between these two?

This is the information my usual shop gives on these two:
WD6400AACS
Transfer rate: up to 98 MB/s
5400 rpm
8.9 ms access time
27 dB(A)

WD6400AAKS
Transfer rate: up to 93.5 MB/s
7200 rpm
8.9 ms access time
33 dB(A)

It seems a bit odd that despite the lower rpm, the AACS allegedly achieves the same access times and *higher* transfer rate...
 
Actually the WD6400AACS is also 7200 rpm. But the difference is that the WD6400AACS is from the "Green" line and uses ~6 watts. The WD6400AAKS from the WD "Blue" line uses ~9 watts.
 
so they should be about the same speed? in that case i'll probably go for the AACS as its also quieter (according to specs)... and it wastes less power.
 
the shop lists them as in stock. anyways, I won't be ordering until october, so... let's just hope that doesn't change.
 
Sorry for bumping the thread, but has anyone else noticed that the WD6400AACS can't actually be found on the WD site??
 
Ditto. Also, are you sure the AACS is 7200RPM? Local sources here in India tell us it's 5400..
 
Green series is variable RPM so min. 5400.. that's all I know

I want to order 2 AACS for my fileserver because this shop in particular doesnt have AAKS (I already have one 6400AAKS which is fast & quiet as well)

'Western Digital uses spindle motors that can be dynamically adjusted to a certain spindle speed. This feature is called IntelliPower, and WD specifies the rotation speed at > 5,400 RPM, but also says that it dynamically allocates parts of the 16 MB drive cache memory.

There are also other features named with the "Intelli" prefix: IntelliSeek determines the optimum seek speed to meet acceptable performance while maintaining low power consumption (more power is required if the arms have to be accelerated and slowed down fiercely). IntelliPark moves the heads away from the surface of the platters to reduce aerodynamic drag. This feature can be compared to closing your windows when driving at 45 mph: it does make a difference in your gas mileage, though the difference is certainly small.'

http://www.tomshardware.com/reviews/wd-caviar-gp,1703-2.html

The question remains does this make them less reliable? Adding extra features such as IntelliPark.. which you don't really need..
 
I'm pretty sure variable is BS. The 750 and 1TB version of the GP's are 5400RPM, and it shows in performance. Not a big deal for storage, but something to consider if you're using them as boot drives though.
 
The RE3 and AAKS are very fast and more suitable for a boot disk.

I dont know why you should want to have 640GB for OS+apps/games..
 
Because WD, in their infinite wisdom, refused to make a new model number for the single platter 320GB HDD. The 640 guarantees raptor speed at the market low cost per GB - whats to argue there?

I partitioned my friends drive with ~96 GB for the OS/games/apps and the rest (500GB) for storage. Perfect.
 
Well, I have three of those WD6400AACS HDD's

One of them is death, so it's gonna be a RMA anyway.

The drive speed appears to be locked somewhere between 5400 and 7200 rpm, so it's not adjusted to use (like I though). This sucks bigtime offcourse. Anyway, they are silent and use verry little juice, what is good.

I'm gonna ask WD to trade my death WD6400AACS for a WD6400AAKS and I'll sell the other two to my brother for his 24/7 computer.

What next? > A few more WD6400AAKS discs from the shop.

Just like a lot of people I bought into the idea of adjustable rpm, what appears to be all BS and misleading marketing.
 
Well, nothing works. The WD tool crashes on it. HD Tune can't finish it's test. HD Tune's gives one red block in the Error Scan. Windows install can't copy files and partitioning the discs also doesn't work, etc.

Here is a HD Tune screenshot from one of the other two:

HDTune_Benchmark_WDC_WD6400AACS-00G.png


Tested on a E6600 / 4 GB RAM. OS running from three Seagate 7200.10 250 GB discs.

The normal WD6400AAKS scores around 89-90 MB/s average with 7200 rpm. If you devide this 67MB/s by that 89-90 and multiply with 7200 you get 5400 rpm.
 
I also want a fairly quiet PC.
What's wrong with 640GB? Too big? Too small?
Not wrong.. but I think it's too big just for OS/apps/games for most. Like said, partitioned as boot + storage it's ok I guess.I think it's very quiet too, but I cant notice any difference with 500AAKS or 320JS

AACS is also lesser available and even more expensive here.. will that outweigh the increased energy used by AAKS :confused:
 
So pretty much the verdict is is that the WD6400AACS is simply a 5400RPM drive version of the ever popular WD6400AAKS?

Is this marketed as a "Green Power" drive, by any chance?
 
Yes, it has the green sticker.

Yes, the higher price is worth the difference in case of 24/7 use in a small room, where heat matters, silence is important and every Watt saves you € 2 a year.
 
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