Ok so with a little work inside the case, I added a 3rd HDD.

DISK1 
C: OS & Music Apps
D: Various media and non related files (Not used during production)

DISK2
E: Sonar Audio (per project folders)
F: Sample waves (Not used during production as I import them into Sonar Audio drive)

DISK3
G: Softsynth Library data (stream etc)


Happy with this now.  Thanks to everyone for posting.  ;>

I'm going to go against the usual recommendation to always use "separate, one-partition drives" under all circumstances.
Perhaps I'm wrong, in which case, please correct me . . . .
 
I agree, separate drives are always good, because apparently Windows can seek data on each drive simultaneously. I'm just disagreeing with the partitioning part. I don't see the value of always having only one partition. Two examples:
 
1. If I had a disk with two partitions, and there was a lot of empty space on the disk between partitions, the heads would have to move a greater distance to access the data on the different partitions. This would slow performance.
But suppose I have one disk almost full entirely full of streaming sample data. My song needs to access two samples at the same time -- one sample is located toward the outer part of the disk, and the other is located on the inner part of the disk. Why is there any difference in seek time if the samples are located in different partitions as opposed to being on one partition? Don't the heads have to travel the same distance for the seek?
 
2. Supposed I have two 1 T disk. On one disk I put the OS, and on the second steamed Audio data. Then, I created a 2nd partition on the OS disk, and on that 2nd partition I kept storage files such as backups, etc. These files in the 2nd partition would never be accessed during operation of the DAW, so all the head seeks would be in the first OS partition. Why would having the 2nd partition have any impact on audio performance?
 
That being said, bitflipper in a 2009 post said, "When you partition a drive, you're making smaller cylinders. Partitioning makes sense only for higher-level data organization and not for efficiency, which actually suffers. For maximum speed, you should always make the entire drive one partition."
 
I've been trying to research his assertion, but I can't find anywhere that "partitioning a drive makes smaller cylinders".
 
If I understand correctly, a cylinder is made up of  tracks that are lined up vertically underneath each other on the platters. Partitions are created in horizontal concentric circles on all platters, moving from the outside to the inside of the platters. So how would making a partition reduce the size of the cylinders? As far as I can see, it would only reduce the number of cylinders, not the size, so this shouldn't affect seek performance.
 
My conclusion:
1) When a drive is full or almost full of data, partitions should not decrease performance compared to having no partition.
2) Secondary partitions used for storage files should not slow performance (as long as they are created after the first partition, thereby positioning them toward the inside, slower part of the disk).
 
I'd appreciate some opinions on this . . . as I said, correct me if I'm wrong. Thanks.
 
 

raja
1. If I had a disk with two partitions, and there was a lot of empty space on the disk between partitions, the heads would have to move a greater distance to access the data on the different partitions. This would slow performance.
But suppose I have one disk almost full entirely full of streaming sample data. My song needs to access two samples at the same time -- one sample is located toward the outer part of the disk, and the other is located on the inner part of the disk. Why is there any difference in seek time if the samples are located in different partitions as opposed to being on one partition? Don't the heads have to travel the same distance for the seek?
 
2. Supposed I have two 1 T disk. On one disk I put the OS, and on the second steamed Audio data. Then, I created a 2nd partition on the OS disk, and on that 2nd partition I kept storage files such as backups, etc. These files in the 2nd partition would never be accessed during operation of the DAW, so all the head seeks would be in the first OS partition. Why would having the 2nd partition have any impact on audio performance?
 
That being said, bitflipper in a 2009 post said, "When you partition a drive, you're making smaller cylinders. Partitioning makes sense only for higher-level data organization and not for efficiency, which actually suffers. For maximum speed, you should always make the entire drive one partition."

I've been trying to research his assertion, but I can't find anywhere that "partitioning a drive makes smaller cylinders".

If I understand correctly, a cylinder is made up of  tracks that are lined up vertically underneath each other on the platters. Partitions are created in horizontal concentric circles on all platters, moving from the outside to the inside of the platters. So how would making a partition reduce the size of the cylinders? As far as I can see, it would only reduce the number of cylinders, not the size, so this shouldn't affect seek performance.

My conclusion:
1) When a drive is full or almost full of data, partitions should not decrease performance compared to having no partition.
2) Secondary partitions used for storage files should not slow performance (as long as they are created after the first partition, thereby positioning them toward the inside, slower part of the disk).
 
I'd appreciate some opinions on this . . . as I said, correct me if I'm wrong. Thanks.

I used to do design and manufacturing of HDDs for Seagate years ago, so will confirm that Bitflipper's comment (and your understanding) is correct. Partitions are cylinders so 1) size can be precise, and 2) all heads are active for each partition made.
 
As far as performance, a little forethought needs to go into how partitions will be used. If a drive is partitioned where they are used for different/isolated purposes, then the heads will stay closer to "one data" set, rather than have to jump partitions (which does reduce performance). In fact, for HDD only (never on an SSD) doing a full optimizational defrag will group files (especially those used often and read-only) on adjacent tracks so that access times are reduced. For this reason, I do not endorse partitioning unless OS restrictions require you to do so (i.e. I have a 3TB drive partitioned because I can only see 2TB of it if I did not).
 
This relates directly to other points made about the OP... the OS drive gets a lot of read/write activity, and is crucial to the performance of the system. If files on a another partition (on that same drive) are used at the same time (project audio, etc.), the Head Stack Assembly (HSA) is being forced to swing across the platters more often than it would ever need to if it was simply one drive and properly defragged and optimized.

One small point:
 
A lot of people here are recommending no partitions, seemingly for fear that it will hurt performance or cause problems with a DAW.
 
They are right, but only in theory, which has no significant bearing in practice.  Oh sure, multiple partitions on a given physical hard drive will not enable the drive heads to work any more efficiently than having one big partition.  Some efficiency may even be lost because the heads (one for each platter surface that holds data) can be in only X places at any point in time (where X is number of heads).  But heads move pretty damned fast.  It's not an issue!
 
Having multiple partitions on a spinning hard drive does not hurt performance in practice.  If your hard drive has four platter surfaces, your drive heads are positioned over four different places at once already.  One of those might be one partition and three others might be a different partition. The drive is going to get the data just fine and in plenty of time to meet the real-time input and output requirements of the DAW.
 
So partitions don't "really" hurt.  And may help with your organization and administration.  By putting your VST libraries on their own partition (on a separate HDD or on the same one) , you can strategize your maintenance tasks.  For example, static read-only VST libraries don't need to be backed up as often as your recording partition or your OS partition.  Easier to manage if you keep "like with like".
 
For my VST library partitions, which are mostly read-only, I take one full backup monthly and one incremental halfway between full backups.  This is plenty to cover me for any updates I might apply from EastWest, Arturia, or Native Instruments.  Meanwhile, data partitions are backed up once per day and OS/Apps are backed up 2 or 3 times per day (more on weekends when I'm using the system more often).
 
Overall, it's a good plan because I probably have about 1.5 terabytes in use by VST libraries; what a hassle to defrag and back them up daily or weekly!
 
On SSDs, you can partition if you like, it has no impact on performance because there is no spinning disk or moving head armature.
 
In short:  Partitioning or not partitioning will have little impact on your performance, so don't do it for performance.  Do do it for organization.
 
 

In the end, partitioning is more personal preference, for sure. Where I have seen people get burned is making an OS/Programs partition and then filling it up.
 
As to defragmenting... that is not required as often as you are implying. I probably do a defrag with an optimization once a quarter. The best use of optimization is after loading a drive with large programs or data sets. After that point there are not "great changes" in locations unless adding more or modifying those files. As for backups I use batch files with XCOPY targeted to specific directories and to copy newer files only. After the initial run, subsequent runs are quick. The one I am specifically religious with is the one that gets data off my SSD and onto the HDD.
 

Positively Charged
Meanwhile, data partitions are backed up once per day and OS/Apps are backed up 2 or 3 times per day (more on weekends when I'm using the system more often).

 
I am confused with a comment in your post about "backing up OS/Apps" 2-3 times per day... both of those are relatively static, or does that mean the OS/Apps partition of your drive (I am assuming the latter)?

Sorry Bob, that was directed at the post above yours, let me edit mine quick.

mettelus
Sorry Bob, that was directed at the post above yours, let me edit mine quick.

Oh - I knew you were not directing that at me - I just thought I would explain further for others.  :)
 
Bob Bone