Hmm. With 20+ years of active service tech under my belt ... a couple of thoughts.
"I defrag very often". I hope you are NOT defragging the SSD ? Because defrag + SSD = water and fire. SSD's have their own management and not only do not need but utterly hate defragging. The only thing you're doing if you're defragging an SSD is shorten its lifespan. You probably know that, but still i think it wouldn't hurt to mention.
Look what the machine does in Safe mode. Is it fast in Safe mode ? Problem will be 99% software related. Still same slow speed ? Hardware related.
You COULD be looking at a failing piece of hardware, like a defective HDD which your system desperatly tries to correct.
When I observe, mostly the processor runs up to 20%, won't go higher. No idea, I tried every possible thing, that's why I suspect it can be a hardware error.
What brand of HD is in the machine ? Even a badly defective HD can put out a "SMART Status OK" type of message, but the drive is actually dying.
This would explain the slow speed without the cpu being stressed. Your machine would be WAITING on the drive subsystem to get ready, which is currently trying to recover from a hardware error. Ah, and defragging a dying harddrive is probably the last thing you want to do ....
Yeah that sucks. Yeah that should not happed to a 10 month old machine. But I know drives can be dead even brand new so ....
Nearly all brands permit free download of a hard disc diagnostic tool. These days, most brands will belong to either Seagate (stuff like Seagate, Samsung physical drives ... all Seagate these days) or WD. Download the appropriate HDD diagnostic and let it run. I would not be surprised the tool will tell you the drive is on the way out.
RobotChicken :
Rant mode On.
Here's my take on this, with my ACSP certifications under my belt too ...
THAT (the hard drive vulnerability) by the way is the main issue with MAC's : their "health system" depends pure on the SMART system of the drive. And by all means, that is total BS and says totally NOTHING about the state of the drive. I've repaired Mac's which stated "Smart Status OK" only to discover the ******** drives were dead as doorknobs. Which you can NOT test on a Mac as there's no trustworth HD diagnostic software there : and I'm talking about mfg'er diagnostic software from guys like Samsung/Seagate/WD .... as they simply do not MAKE this for anything else but Windows platforms. Yeah sure there are a couple of HD diagnostics on OSX too, but the ONLY software that really does check a HDD or SSD like it MUST be done is made by the mfg'er of the drive and guess what, they do not make that for OSX. NONE of them !
AHT ? Does nothing else but read out the Smart Status. Again, totally worthless.
So yeah I can make a ISO thumbdrive or CD even with the software on it and I can boot from them on a Mac, only to find that on new MACs, the stupid USB ports won't initialize so I get the diagnostics started, but I can't bloody activate or control them.
Nice going Apple ! Or Apples with Micron SSD's : the system would simply revert to an earlier state, erasing EVERTHING you had before "the time machine effect" or leave your with a complete empty drive, without an OS even. I KNEW there was something fishy with them as I had dozens of customers with this problem on the Macbook Pro's, but it took Apple a full year to admit there "was a problem with certain batches of SSD's and they all had to be replaced". Yeah like I didn't know that already, bunch of idiots.
Defective GPU's ? 2 years later Apples tells us "ah yeah that's funny, those things did die, but we can now offer a free repair". Sure, by that time most of the affected machines had been scrapped anyhow as Apple's repair bill was so high nobody repaired those defective Macbooks anyhow. Smart people at Apple !
The times I've cursed Apple for their glued Imac design because of this, you would not believe. I bloody HATE Apple for this, and I've got a 27" 2012 Imac myself and a Macbook Pro. The times I've argued with Apple repair because of a defective drive which they THEMSELVES are not able to detect (Apple Repair simply throws a clean OSX install on the drive and if that works, it's "repaired" and they will ship it back to you as NTF (no trouble found) AND a bill even though the thing is in warranty) as their OWN certified repair points LACK propper software to do something so demanding as a full hardware check of a harddrive with the drive INSIDE the machine.
On older Mac's, I could disassemble them leaving little to no trace, take the drive and test it on a PC which -using the correct software- would clearly show "drive is defective and has to be replaced". These days with the glued shut Macs, doing that will void warranty. On the latest Macbooks, the SSD's are even fully integrated on the mainboard. SSD fails ? Data byebye, SSD byebye, Mainboard byebye. Oh yes, that's progress according to Cupertino.
So no, this is my LAST Mac. ***** them. I'm going back to PC for sure. Pieces of overpriced, obsolete-from-the-moment-they-are-designed crap. And I'm not saying this lightly and I as an ACSP, I do know a _little_ about Apple Macs and what can go wrong with them, as I am the guy who's got to repair them when they break down -and they do break down, not more often, but also not less often than any comparable quality Windows-based device. The difference is : with non-Apple based devices, you can actually have access to free and working diagnostic stuff that helps you to make a case against the mfger when need be.
Ah, and in terms of TCO (total cost of ownership) which is something Applefans like to wave with : my 2012 Imac has a 680GTX VGA part. The bloody machine costed 2500€ and is 3 years old. My son's PC is now hitting 7 years, running on a first gen I7 950 cpu. We both play Doom4. His machine runs circles around mine, because I could upgrade his machine for 100€ with a new VGA part that is about 3x faster than the overpriced, non-upgradable VGA part in my Imac which was top-of-the-line according to Apple back then. So basically, the 7 year old PC which costed half of my expensive Mac copes BETTER with today's software than my Imac does.
Around the same time, I bought a no-name I7 gaming laptop for my wife (generic Clevo design).
Came with a R290 which was totally NOT top of the line back then when Apple sold their customers the 680part as "nec plus ultra".
Result ? That laptop too runs Doom (for example) about 3 times faster than my Imac is capable of. And although "just" a laptop, it is actually much more configurable and upgradable than the Imac. The VGA part can be upgraded (MXM slot), the thing has 4 (!) SATA3 ports internally accessable by the user, so I can put in 4 SSD/HDD drives just by using a screwdriver.
And that machine costed 1/3th of the Imac with a warranty periode twice as long.
And before Applefans start yelling "ah but that's in games, in real world applications the Mac is so much faster and better" .... no actually they are not. Not even close.
My Imac came with the utterly crap "fusion drive" system which doesn't even allow SSD operation when running Bootcamp due to Bootcamps "can't install over 4th partition" limitation. Hence, any Bootcamp on a Fusion equipped Mac can NOT access the Fusion part, so of course the PC part will be slow as hell. Apple fails to mention that little detail in their sales pitch, and I actually know Apple fans using this effect to show "how fast OSX is compared to Windows on the same hardware". Morons.
And yes, you can prevent this by decoupling the Fusion drive. Which leaves me with 2 SSD partitions of 64gig each. That's a joke and unusable, not to mention that according to official Apple guidelines, this ACTUALLY VOIDS YOUR WARRANTY. So let me get this straight : changing my SOFTWARE setup can void my warranty ? Yep, only Apple makes it possible. Or you can use some ******* awefull version of a virtual machine like Parallels (the utter piece of ***** if there ever was one) which does allow you to use the speed of the Fusion drive system, at the penalty of falling back to 1/3 of the speed of the graphics system not to mention the loss of real compatibility in terms of such high tech cutting edge hardware as your USB ports as the emulation of those ports sucks monkey balls -being the most polite way to put it-.
Had to solve that by running the PC part from an external SSD over Thunderbolt (really elegant ! like NOT). Upgrading the internal drive ? Good luck. You have to tear up the complete Mac and after that, you'll still have issues as the temperature sensor of the Imac will fail afterwards, leaving your fans running at 6000rpm or so making the user bat****crazy as a result. Oh yes I can solve this, but those issues should NOT exist on a "superior machine"
.
On my sons old I7, upgrading is a question of opening the machine, swapping the drive. Ready.
Yes I could have bought a Mac Pro. Which would have costed me double of the Imac, and NOT be any better than my sons old I7.
Fact.
It's like Luckey Palmer (Oculus Rift) said : "we'll support Mac when they stop making crap machines".
Rant mode Off.
It bugs me, especially that I'm unable to do pretty much anything lately as I said, the rendering program has gotten SO LAGGY, that the video there doesn't even want to go smooth, it's like a terrible slideshow - unable to work.
Even if I have only my internet browser open, it lags often.
So, after checking everything - only hardware option remains. :/
As said, first try safe mode. Still slow ? Hardware. Most probable culprit : defective hard drive which in my experience is the source of 70% of all hardware issues on PC's.
As this takes us very much outside the scope of this thread, just contact me on email. With a bit of luck, I can identifiy what is going on with your machine as this is what I do/did for a living biggest part of my life.
And sorry to hear about the knife-that-clearly-hates-you.
I hope I didn't contribute to that in some way today because I would REALLY feel bad if that would be the case.