I/O prioritization

When you use adobe photoshop, and you have multiple disks, photoshop starts by telling you to specify a scratch disk other than the C drive, this is because hard disks are ubnlike memory "slow" and are a bottleneck when you are saving your work directly to disk, Also when you run out of memory, windows makes a swap file and uses it as if it was memory (not exactly as the least used go to disk but in simplification here), So, we know magnetic hard disks are slow, Flash memory is comming to the rescue in the memory case, but it still will not do the trick,

Now although slow, was also never optimized, If you were copying large files to disk, your computer tended to become slow, this is because the disks are not responding and too busy with the task at hand (you know your disks are busy by the flashing lid on your computer's chasis).

So, now Microsoft claims to have organised this a bit, Not only optimizing the use of Serial ATA (SATA), and the ATA (the thick ribbons), but the process of Input Output to the disks all togerther.