I need to upgrade my 2TB drives to 4TB and like Hitachi since that is what I have now and they been great.  I need to get 3-4 drives to start and the two models that are out there are:

• H3IKNAS40003272SN (0S03664) - 64MB - 7200 RPM
   
  
• H3IK40003254SP (0S03359) - 32MB - 5400 RPM (coolspin)
  

 

Price is pretty much the same and are within a few bucks:

• $143 Newegg (7200 RPM)(4 for $600 - $25 AMEX)
  
• $139 B&H Photo (5400 RPM)
  

 

My sever is really just for storing movies and watching them on my HTPC.  It's been a while since I needed new drives and I haven't been able to keep up with all the reviews, so was hoping to get some advise as to which of these drives would be preferred for my unraid server.  Wasn't sure if the faster speed of the 7200 RPM drive was preferred over the lower temps of the 5400 RPM drive.  The newegg deals expires today, so if I go that route then I need to pull the trigger soon.

 

Thanks in advance

The biggest difference will be on writes to your array (since you are not using a cache drive) and any operation that involves the use of the parity drive--- parity checks, disk rebuilds, etc.  Reading speeds across the network will be essentially unchanged.  Remember that times for things like parity checks will approximately double when you make the shift to 4TB drives regardless of which speed drive you chose.  Since you are already using Hitatchi Deskstar 5K3000s which are a slower rotational drive, you already have a reasonable benchmark of what your performance will be with the slower drives.  If you fill the array with 7200 units, you might see some improvements in performance as compared to the slower drives.  I assume that you will be starting out with just two drives (why spend the money on rebuilding the whole array at once.  4TB drives will probably to cheaper six months from now and, perhaps, even less than that a year from now when you need the storage space), you probably won't see much improvement in speed using the faster drives. 

The biggest difference will be on writes to your array (since you are not using a cache drive) and any operation that involves the use of the parity drive--- parity checks, disk rebuilds, etc.  Reading speeds across the network will be essentially unchanged.  Remember that times for things like parity checks will approximately double when you make the shift to 4TB drives regardless of which speed drive you chose.  Since you are already using Hitatchi Deskstar 5K3000s which are a slower rotational drive, you already have a reasonable benchmark of what your performance will be with the slower drives.  If you fill the array with 7200 units, you might see some improvements in performance as compared to the slower drives.

It would be nice if getting the 7200 drives would improve the speed it takes writing the blu-rays to the server (I use makemkv).  However I never know if the limiting speed is the optical drive, my PC, my network, or my server drives.  I guess I could rip a blu-ray directly to my PC, which would eliminate the network and server, and compare that to the time it takes to rip to the server.  When I got my previous drives it was basically whatever Hitachi was on sale at the time and I never cared that much about the speed.

 

I assume that you will be starting out with just two drives (why spend the money on rebuilding the whole array at once.  4TB drives will probably to cheaper six months from now and, perhaps, even less than that a year from now when you need the storage space), you probably won't see much improvement in speed using the faster drives.

 

I probably need to pickup more then 2 drives since my server has been full for a while and I have been using a a 4TB WD My Book for extra storage.  I know drives will get cheaper over time but would like to do something soon because if the My Book fails then I loose all that data.  I finally rebuilt my sever today with a new case, PSU, and added hot-swap cages so I can access all the drives from the front.  So I would need to pickup at least 3 drives for now because that will give me 4 TB of extra storage and I already have 2TB of data on the MY Book.  So the 4 drive deal at Newegg would also work for now and give me some extra storage.  Another thing I have to consider is my old server case (antec 300) had fans blowing directly on the hard drives, where as my new case (antec 900) does not since I used 7 of these:

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16816215323

 

So I was thinking the cool spins might be better since those run cooler and I don't have the air movement across the drives that I used to .

If you are ripping directly from Blu-ray disks to your server, your optical drive is probably the slowest link in the chain.  I know that it takes (at least) twice as long  to rip a Blu-ray using DVDFab to my hard drive than it does to build those files into an ISO that is being stored on my server using ImgBurn.  The average speed of this ISO burn is about 40Mb per second.  (The transfer begins at +80Mbps and slows to <30Mbps after the memory cache fills up.)  I don't do it that often so I am not really that concerned about the actual time required.