I thought it meant hard drive read/write capacity, but i took this screen shot of a drive at 100% but nothing happening.
Often times it will go to 100% when reading a few hundred kb/s and the drive can do a lot more then that.
Not sure why yours is doing that, mine doesn’t do it at all.
A quick google gave me these possible diagnosis’:
File Indexing
By default Windows regularly looks for new or removed files on your file system and writes the results to a database. This is called file indexing and is used for the Windows search which you use to find a file or an application.
If you don’t want or maybe also don’t need Windows updating the database every now and then, disable it in your control panel.
Power Plan
If your power plan is set to Balanced try to change it to High performance and observe your system. Maybe you see the result after a reboot.
Automatic Defragmentation
Yes, Windows 8 still has the same fragmentation flaws as older versions. This is based on the file system NTFS by its nature. Other operating systems such as Linux also have fragmentation but their well-designed file systems, e.g. ext3 or ext4, have a way better algorithm to avoid fragmentation as much as possible.
Automatic Windows Updates
In some cases the system got unresponsible when it got updated automatically. If you are having performance problems while it’s preparing or installing an update turn the automatic update off. It’s recommended anyway to update your system yourself as not every automatic update improves your system. A recent Windows update was faulty and could lead to a non-bootable computer. If you update manually you need to be disciplined, you have to read the update news and what changes are being applied.
That has nothing to do with the drive performance. There is some process accessing the drive continuously. Could be an AntiVirus.
Check with ProcessMonitor or Ressource Monitor. This will show which process it is.
This, also your built in Windows Defender might be active as well. Personally I think if you practice good internet etiquette anti-virus and malware software are relics. If anything they just eat up resources and slow your computer down. I've stopped using background programs for almost 8 years now and just run a battery of tests if something seems fishy.
Resource monitor will tell you exactly what's using your disk.
Calvin you sure have a lot of hard drives there… or is it just 3 or 4 big ones formatted into multiple smaller ones? Never seen a 559gb hard drive before…
It’s a 600GB SSD by Intel. 
Ah right, that makes sense Ryan.
I know its not indexing (first thing i turn off when i install windows), and i don’t think its updating, but that is an extreme case, often i see 80-100% when a drive is accessing but nowhere near its capacity, say 5-20mb/s.
But i will check resource monitor and see if i can figure it out.
I wouldn’t over think this. There doesn’t seem to be any problem with your computer besides you suspecting that what you’re seeing is unusual. I don’t think it is at all. Even if the read or write speed showing is not “near its capacity” that is not unusual. You’re only going to see its capacity when you are transferring large files. During other normal idle time or standard computer usage the disk isn’t going to be doing much work.
I can read at 200 words per minute when I’m focusing on speed reading through a text, but when I’m reading the newspaper or the back of a label my speed will only be 100. This doesn’t mean there’s anything wrong with my eyes! My reading speed will also be decreased significantly if I have to read text that is separated my numbers, images, and having to turn the page. Your read and write speed is slower when accessing smaller chunks of data. That’s why hard disk testing tests 4K, 512K, and full sequential speeds.
Your task manager is not a dedicated disk monitoring tool and the values are only indicative. If you doubt its performance try a tool like http://www.hdtune.com/ or Crystal Mark.
Bort and overthinking go hand in hand, i noticed my SSD also can go to 100% and only be accessing 10-20mb/s, so that cancels the non sequential small files all over the drive theory, but i will keep searching for the answer.
Not over thinking or make a complex blue print out of it ;-).
This is not related to the Disk I/O, write speed or whatnot.
“Active Time” just means the drive is active 100%, in a word: online. A process is continiously accessing this drive. Even if it’s only 1 MB/Sec (or even lower).
If it has a break, the percentage goes down.
That makes sense but sometimes i am waiting for data to be read and its only going at a low percentage of the drive’s capacity and they are long sequential files but the active time is at or near 100, for example my 2TB drive reads at 110mb/s at the beginning and 40mb/s at the end (slowest) part of the drive, yet sometimes it can be at 100 reading at 5mb/s and can’t go any faster (sequential single large file copying) so thats why i am thinking its not just in use time, and the destination can receive data much faster as well. Also the CPU load is not high unless the antivirus or other process is designed to only use a percent of a single or multiple cpus.
I've gone through a couple of builds now and I usually start from scratch so my old OS drives end up becoming storage in my new builds. I was also given random drives by friends that just end up being added to my system. No formatting, yes that's an Intel SSD as Ryan noted.