Multiple HDD (IDE and SATA) numbering

I recently added a new HDD SATA to my computer.
Before I had only one IDE HDD.
I converted the SATA one to dynamic disk.
In "disk management" it shows: Disk 0 - IDE HDD(old one), Disk 1 SATA HDD(the new one).
After converting the SATA HDD from dynamic disk back to normal disk(using Partition Wizard application), the numbering has changed. Now, the SATA one is Disk 0.

Is this important? Could it cause some performance issue? Or it's just an identifier used by Windows 8.1?
Thank you in advance.

Also, I have to mention
The old HDD: WD - 320 GB (IDE)
The new one(added 2 days ago): WD 1TB (SATA) connected on SATA port 2.
SATA PORT 1-> DVD-RAM.

windows will assign the Disk ID and it does not matter