When using SSD, how to turn HDD off when not used?

Hi, I'm going to have a Dell E7440 soon and I plan to put an 840 EVO msata on it when it came out. The laptop came with a 2.5'' 5mm 500G HDD, however, I remember its HDD takes about 0.3w+ while idle. The battery only has ~33WH, so 0.3w is actually impactful here. Is there a way to turn HDD off until I use it? (Like taking a mobile hard drive with the machine.

Besides HDD+mSATA:
If I use msata SSD as a main drive, will it ever get overheated and throttled? 500 HDD+240G 840 EVO msata vs 2.5'' 240G 840 EVO, any recommendation?

I actually got a 840 EVO on BF for $150, haven't even opened yet. I'm wondering if I should use it directly when my machine comes or wait until the 840 EVO msata, is it going to be much more expensive? Seems the MSRP is only $10 more expensive than the 840 EVO 2.5 version, but the MSRP is around $1/G

Thanks!

 

The OS should be able to spin down the drive when not in use, so so long as you don't try to access/save data on it (either you or the OS/Programs), you should be fine.

If you want to make sure nothing on the computer can use it until you want it to, I suppose you could dismount the HDD until you need it.

 

Hard Drive - Turn Off Hard Disk After Idle or Never - Windows 7 Help Forums

The setting wont affect SSD.

 

Depends how the HDD is setup, or even the last file that was used on the drive; it may never go idle and therefore it will never sleep as suggested above.


As for the 0.3W being 'impactful' vs. the batteries stated capacity - doubt it. Unless you think you use your computer less than a minute every 110 hours or so... it won't make a significant difference in battery run times (less than 10 minutes in my estimation).


And that is just not enough to worry about. (The SSD will be making a bigger difference).


Take care.

 

Depends on the hard drive and APM setting in it's firmware.

My HGST 7K1000 never spins down even with Windows settings to turn it off and hard drive utilities can't change the APM either which I like since spinning down and up mechanical hard drives to many causes wear to motor and in time will kill the disk a lot faster.

Aggressive APM settings are only found on laptop hard drives to get more battery run time similar to SSD's DIPM/HIMP settings which are built into the SATA controllers driver and can be set in Windows Power Options also if enabled in the registry but unlike mechanical drives SSD have no moving parts so having DIPM/HIPM on only slightly affects the SSD's performance while significantly reducing idle power consumption and battery run time.

 

As far as I can see, the method you mentioned enables to turn off HDD when the laptop is not in use, while OP wants to turn off the HDD when still using the laptop.