Three PC issues I'm dealing with

I’ve already subscribed to this subforum 🙂
I’m dumping all three of my headaches into this one thread because, honestly, it feels like they might all be part of the same messy knot. Let's take them one by one:

1. My old drive finally kicked the bucket, so I swapped in a new one. I did everything by the book—SATA cable, power connection, initialized it, the whole nine yards—and it seems to be running perfectly fine. But here’s the kicker: for some reason, macOS (7) keeps treating it like an external hard drive. It’s a 3 TB drive with two partitions (1 + 1.72 TB), just a standard basic disk.
2. My CPU usage is through the roof. Task Manager shows that "System" is constantly hammering away, writing god-knows-what to the disk (my SSD, not the one I just mentioned).
It eventually settles down after a while, but when it starts acting up, it drags on for at least a solid half hour. It might not sound like a total catastrophe to some people, but when there's no obvious cause, it smells fishy to me.

Those first two issues are brand new.
The third one has been haunting me for a while now.

3. Sometimes, when I boot up or restart, right after that initial BIOS splash screen, macOS just gives up on loading. Everything just freezes mid-way, and nothing happens. If I force it off and then turn it back on, or just hit restart, it works perfectly fine. And it does this constantly—like, every other time I try to boot. For a while, I was naive enough to think it had something to do with some weird glitches with the DisplayPort 🤦 😁 (since it seemed to happen mostly when I'd restart after hooking it up to my TV), but that's probably just wishful thinking.

EDIT - adding a fourth one to the pile:
- Windows Update is sitting there offering me 92 (!) updates, which it tries to start downloading and then just sits at 0%. And stays there. And stays... This has never happened to me before.

I would appreciate any diagnosis or even just a shred of useful advice from the heavens! 😉

I honestly think all four of these issues stem from the OS itself...
Just wipe it and reinstall. That’ll probably clear everything up.
If you've got a backup or another PC handy, try formatting the Hard Drive and see if it actually shows up then...

There are a ton of potential issues here that might be linked, or they might not be, so I'm not sure which ones need direct fixing and which ones will just sort themselves out once you fix the root cause.

First off, there's the OS. It can cause all sorts of headaches with a Hard Drive. When you install a Hard Drive, you really should have switched the drive mode to SATA in the UEFI (some people swear by it, others say it doesn't matter). If you want to know why, just Google "Hard Drive, SATA, TRIM."

But before even touching that, you should have updated your UEFI to the latest version because probably the UEFI isn't recognizing that 3TB drive. It’s a known issue—these types of problems happen constantly with 3TB drives. If the UEFI actually recognizes it properly, then you just have to hope the OS picks it up and formats it as an NTFS drive—assuming you've installed all the necessary updates.

Antivirus software can also mess with a Hard Drive. For instance, there are plenty of reports that McAfee causes similar issues with constant Hard Drive activity and high CPU usage. I won't guess about other software, but once you deal with the UEFI, try disabling your antivirus for a bit to see if things improve.

Also, the power plan can be a culprit. For some reason, it might have defaulted to a power-saving mode that's screwing you over. Check that and set it to "High Performance."

And grab Device Manager (like CPU-Z), a little utility that shows you (among other things) what speed your CPU is currently running at. Open it up, and if the CPU is working right, you'll see the multiplier changing and the frequency ramping up whenever you actually put a load on the computer. Sometimes the CPU (whether due to UEFI settings, power plans, or whatever) just gets "stuck" at a low frequency and acts like an idiot, making it look like it's hitting 100% usage when it's actually just crawling.

I'm also assuming you installed all the drivers and system utilities from the motherboard manufacturer's website, because that's non-negotiable for everything to run correctly.

It wouldn't hurt to open Activity Monitor and check the Threads too—you should be able to easily spot which Thread is eating up all your CPU cycles, which will tell you exactly what's causing the trouble...

That's it for now. Try some of this and let me know how it goes...

Edit:

Issues 3 and 4 will probably resolve themselves; they're likely just a side effect of the UEFI failing to recognize the drive.

Thanks a ton for the deep dive response! 🙂
I’ve gotta weigh in on a few things here.

darkowl72 said:First off, you've got to look at the SATA settings. Those can seriously mess with a Hard Drive. When you're setting up a Hard Drive, you really ought to—some swear by it, others say you can skip it—switch the drive mode to SATA in the UEFI. If you want the lowdown on why, just go grab a coffee and Google "Hard Drive, SATA, TRIM."

I didn't actually install it myself—the folks over at the big-box retailer where I picked up the PC handled all that. Plus, this whole headache (the restarts, specifically the fourth one) didn't even show up right away; it wasn't happening when it was brand new.

But before all that, you should probably flash your UEFI to the latest version because it's likely that your current UEFI isn't even recognizing that 3TB drive. It's a total known issue—like, everyone knows those massive 3TB drives cause these exact headaches.

You hit the nail on the head there: the UEFI isn't seeing it either, and honestly, I haven't touched the firmware since day one. I'll get around to fixing that once I figure out how to actually pull it off without breaking everything. 😬

Antivirus software can be a real pain with Hard Drives too. For example, there are tons of reports about McAfee causing similar issues with constant Hard Drive activity and spiking the CPU usage. I won't guess, but once you deal with the UEFI stuff, maybe try disabling the antivirus for a bit just to see if things settle down.

This whole mess only started recently, and it seems to line up perfectly with the problems I'm having with my old drive. It might be a total coincidence, but this wasn't happening until about a month ago (right when the old drive started acting like it was dying). Who knows, maybe the Hard Drive is kicking the bucket too.
I haven't noticed anything weird coming from the antivirus side of things.

Is it possible I'm just working the drive too hard? I've had this setup running for about two years now. In those two years, I rarely ever shut it down, so maybe I just ran it into the ground and it's simply reached the end of its life. I mean, it hasn't been under heavy load constantly—it sits idle most of the night and a good chunk of the day—but yeah, the power stayed on. Now, whether that's actually relevant...

Sometimes the CPU just gets "stuck" due to UEFI settings, power plans, or whatever else, and it stays pinned at a super low frequency, making it act totally stupid and look like it's hitting 100% utilization.

The CPU isn't actually hitting 100%, but it's definitely pulling way more weight than what I'm used to (even with nothing open). Since it's a 4-core setup, two cores are working overtime while the other two are idling, which brings the total idle usage to about 25%. That doesn't sound like much on paper, but it sure does to me, because usually, it's sitting pretty at around 5-6%.

Look, it isn't exactly rocket science to just pop open your Activity Monitor and take a peek at the Threads—you really ought to be able to spot which specific little culprit is hogging all your CPU cycles, and then you'll finally know exactly what's causing all this headache...

The real problem is totally invisible; everything looks perfectly fine on the surface. If you check the Threads, everyone is sitting pretty at 0% usage.

Updating the UEFI actually knocked out two birds with one stone: my hard drive is finally being recognized, and Windows Update isn't acting up anymore. As for those other two headaches, I can't really give you a definitive verdict just yet—I need some more soak time to see how things shake out. On the bright side, a restart works perfectly fine now without any of those annoying freezes, and regarding the CPU usage... well, it’s hard to say for sure since I’m only glancing at the Activity Monitor every once in a while, but things definitely feel a bit smoother overall.

Honestly, I might just bite the bullet and do a clean reinstall of the OS down the road to wipe the slate clean and hopefully kill off whatever lingering issues are left.

Anyway, thanks a ton for the assist, your suggestions actually worked!😉