Solved Multiple HDD on 2015 System. Slow boot times. any tips?

Hi. I am new to this forum and I apologise that one of my first actions is to seek help for an issue with my Windows 8.1 PC

I have spent time scouring around the forums but I have not been able to find a solution that works.

My question is: What are the optimal settings for a quicker windows boot on a computer with the following HDD:
1x SSD 512GB (Boot, Crash dump, Primary partition), NTFS with 385MB EFI system partitions
3 x WD Black 4TB (all primary partition, one has the page file) These are NTFS with no EFI partitions
3 x WD MyBook Studio 3TB via USB. I have for some reason got EFI partions each 200MB on these

I had to do a complete reinstall owing to an Atheros Killer driver problem which was causing BSOD's every few minutes. Since doing this and updating all my drivers from the official sites I have no more issues with BSOD's but I have been experiencing slower boot times and I thought that this was due to the sheer volume of storage I have. PReviously the system would go to desktop within about 20seconds and now it is just over a minute.

From what I have read I should specify the boot order int the BIOS so that the drive with the boot loads first. I have done this but is has not made any difference.

I have enabled / disabled fast boot with little difference.
I have disconnected the USB drives but again no difference.
I have disabled uneccessary startup services but I wonder if this issue is before Windows begins to start any processes in the first place and I wonder if it is something to do with a hardware conflict upon loading. I also wonder if I have formatted and specified the drives wrong as I am not sure why all the external drives have EFI partions and none of the media drives do.

I wonder if there was a simple solution to this. When I say slow boots, between the MB slashscreen and Windows desktop is about a minute. Not slow perhaps by 1999 standards but here is my system spec:
i7 5930k (not OC)
Gigabyte x99 Gaming 5 onboard sound, onboard ethernet
32GB Corsair Vengeance DDR4
Palit GTX980 4GB (not OC)
Intel USB3.0 PCIe card (I have not devices at the moment using this)
Kingston 512GB SSD
3xWD Black 4TB
USB devices: 3x3TB USB3.0 HDD, 1xWacom nano receiver, 1xLogitech Unifying receiver, 1xAsus Bluetooth 4.0 Receiver, 1xMS Lifecam HD.

I would be most grateful for any help. I have attached the current HDD settings.

I also have 3 USB HDDs attached to my Win7 Computer. One thing that can slow the boot time down is that the BIOS or Windows has to look at each and every attached drive to locate the boot files necessary to start the Operating System.

Another thing I'd look at is the U, V, W, X, Y, and Z drive lettering. By default Windows starts assigning drives letters starting with Z and working back up the alphabet for NAS/Network Attached Storage drives, I have Z as a WDC 1TB NAS drive and X as a WDC 2TB NAS drive, both attached to my Router via Ethernet cable. The bottom end of the alphabet is available to USB drives when needed.

Also involved is the possibility of having a card reader in the computer, I do but the slots don't show in Disk Management but do in Windows Explorer [File Explorer in Win8 and newer]. Or in other words, all the devices attached to the computer have to be enumerated during the boot process.

I'd also wonder if rearranging the drive connections to make the C: drive as Disk 0 instead of Disk 3 wouldn't help.

Thank you for your advice, I will give it a go and see if there is a boost. I hadn't thought there was any consequences for the naming of drives, I did it mainly for aesthetics /) but I'll try that too.
I did find another problem that was slowing the boot however. I had an unspecified device (unknown device) in devices. I went to the ID of it and found it to be related to a DVD conversion software that my PC came with. As I don't use it I have deleted and uninstalled the driver and associate registry entries. I have seen a 30second boost in boot just from doing that!
Thanks again for your help. I'll try what you suggested and post back here.

You're welcome.

JFYI, I didn't see a change in boot time related to the naming convention of the drives. but was interesting to go through the process of rebuilding all my libraries anyway

Ensure all of your secondary disk partitions are Inactive (e.g. using Minitool Partition Wizard). I once had an external HDD with an active partition which slowed down booting.

Hi, thanks for your advice. Just to update -

I eventually tracked the issue to the combination of the Renesus USB Controller and a cheapy [DEL]Tacknet [/DEL] Tecknet USB 3.0 hub from [DEL]Amacon [/DEL] Amazon. it was also causing occasional BSOD on boot when it initialized the external drives connected to it.

I since placed a PCIe USB 3.0 card in the system and now have all USB devices connected either directly to the header on the Mobo or to the PCIe card. The Tecknet USB 3.0 hub is in the bin, there were multiple documented problems on the WWW and non-existent support / reliance on generic drivers which I think were causing issues.

I've learnt my lesson in buying cheap tack and promise not to do it again.

Anyhow I really appreciate your advice. Steve C - I will still check the partitions on the drives, I do apologize for not checking the obvious weak links before troubling you guys.

Needless to say boot times are now much faster and more stable.