Absurdly slow late 15 iMac

[EnderBeta]

Etrecheck shows both the Flash and HDD portions of Fusion drive are active. Even if it was inactive, this system is running significantly slower than an all-HDD machine should work, so why think that replacing the Flash would be a likely fix?

An OS doesn't kill processes due to inadequate mass storage, it kills them due to inadequate RAM.

You clearly believe that 24GB Flash is inadequate for a Fusion drive, but this is not the performance of a system that's primarily or entirely running off a 5400 RPM HDD, it's substantially worse. You may want to see other people do as you have done, and throw a huge SSD into a Fusion drive (I'll refrain from debating that here), but based on what we're seeing here, it's very unlikely that it would fix this problem.

Are you sure you actually want to debate? You don't sound like you want to debate.

You need to keep in mind the OP is updating his first post to keep everyone up to date in a easy and concise manner.

There are multiple factors that need to be addressed with his machine. Needing more RAM doesn't invalidate the need for more SSD or a faster primary drive.

The lack of RAM is killing tasks. He could probably work around that with a memory management software package but it would be a constant pain. The slowness his topic is complaining about is the drive.

The primary SSD in this case is 24GB. At that size it is little more then a cache for the 5400RPM drive. Of course his machine is saying it is using both drives.

A 240GB drive is far from huge. It's enough though to have the entire OS on the flash as well as be able to wake up fast because everything is stored on the SSD instead of the 5400RPM drive.

Increasing the amount of RAM without the SSD is going to exasperate the problem of slowness. Both problems must be addressed to strike a balance.

Obviously I'm not saying spend gobs and gobs of money. However 16GB of RAM and a 128GB or 256GB SSD would make a huge difference in performance even if the 1TB drive (assuming it isn't failing) is still used.

My other point is, opening the iMac is such a pain in the butt if it is going to be done why not upgrade once and not put the machine under the knife more then it needs to be later on.

 

[varian55zx]

I would say sell them both and get a more expensive iMac. If that won't be in the budget, you may have to resort to PC.

 

[EnderBeta]

I would say sell them both and get a more expensive iMac. If that won't be in the budget, you may have to resort to PC.

I don't think that is necessary. With the drives and RAM updated the processor in the machine isn't bad for the OPs uses. He said himself that the machine worked fine at first before it started acting slow. We for sure know the slowness isn't the processor or graphics for his use case.

 

[varian55zx]

I don't think that is necessary. With the drives and RAM updated the processor in the machine isn't bad for the OPs uses. He said himself that the machine worked fine at first before it started acting slow. We for sure know the slowness isn't the processor or graphics for his use case.

No no, the M390 is adequate.

If you're doing basic work the i5 6500 is fine, without a doubt.

Beyond that I recommend 16 gb of RAM and a pure SSD. If those are present in the machine, then you shouldn't have an issue.

 

[ljonesj]

Why do most of you think that the 27in iMac he says he has with the 1tb fusion has a 5400 rpm hd with the 24gig ssd it says it has the 7200rpm hd I've got the same machine and it's fast I have think it's the hd failing but it's my opinion

 

[nambuccaheadsau]

Told 'em that back in #8 but some just keep going on with what they want to believe and knock everything.

 

[EnderBeta]

Told 'em that back in #8 but some just keep going on with what they want to believe and knock everything.

Why do most of you think that the 27in iMac he says he has with the 1tb fusion has a 5400 rpm hd with the 24gig ssd it says it has the 7200rpm hd I've got the same machine and it's fast I have think it's the hd failing but it's my opinion

To the both of you, thank you for pointing out it has a 7200RPM drive. My apologies. nambuccaheadsau, I simply missed your post and didn't see it.

With that in mind since it is already a 7200RPM drive assuming it isn't failing then 16GB of RAM and a 128GB or 256GB PCIe SSD should do the trick nicely without sacrificing the storage capacity of the fusion drive the OP elected to go for when purchasing the machine.

Since Apple sells the iMacs with 8GB as two sticks of 4GB, the least expensive way to upgrade to 16GB would be to buy two more sticks of 4GB memory.

However keep in mind, down the road if you elect to upgrade from 16GB to 32GB or 64GB all of the RAM sticks would have to be replaced. Based on this if it is in the budget I would suggest two sticks of 8GB and operate with 24GB of RAM.

 

[ljonesj]

That's what I got bought 2 8gig sticks even thou it's 1600 ram it works and I got it at the time when it cost 59.99 at Best Buy it's now at 156 like to buy the other kit for 32 but I'm
Not paying that price

 

[nambuccaheadsau]

Be aware the 1600MHz memory will slow down all memory to that speed should you see a slight drop in performance.

 

[ljonesj]

Yeah but I've seen no noticeable difference in the 1866 and 1600 doing everyday things on my imac

 

[anthonyterrell]

I don't think that is necessary. With the drives and RAM updated the processor in the machine isn't bad for the OPs uses. He said himself that the machine worked fine at first before it started acting slow. We for sure know the slowness isn't the processor or graphics for his use case.

Unfortunately I am a huge procrastinator and have to admit this machine has never been fast. I've been hoping more updates would fix something software related.

I've been away on business and have an appointment today at the Genius bar, hopefully will walk away with a plan. I doubt they'll give me an answer today - I expect it to be left over night.

Thanks again all.

 

[purpletalon55]

sucks that your iMac is running so slow mine is the cheapest model they offer and even then I find it fast and I use a windows computer alongside it solely for gaming and youtube content creation and that pc has a sad and this pc with a 5400rpm hdd and 8gb ram feels just as fast, ive never used more than 8gb ram in my life even rendering videos and playing games.

 

[Glockworkorange]

I'd check the Genius Bar at Northbrook Court. Really knowledgeable Geniuses there.

 

[anthonyterrell]

Ended up at the Genius bar a week ago. After the end of the 15 min allocated time they found nothing so the next steps was to attempt an erase and install. I opted to do it when I got home since that day wasn't a good time work wise.

Going to do the erase and install today and see how this up coming week goes. A hassle and even if it fixes it I'm not really happy with the answer, but we'll see. Thanks!

 

[tyche]

Download BlackMagic which is a drive speed test app, run it and post your results. I would put my first guess at a failing drive the symptoms are classic. BlackMagic will at least give you and people a reference for i/o to see its running as expected speed wise.

 

[anthonyterrell]

Did an erase and install on Sunday (4/2/17) and so far it's much faster. This will be my first week of work usage, but still so far it's faster by leaps and bounds. Though I don't trust that since it's a fresh install with no caches and no actual reason why the erase and install worked.

Regardless I am happier now, will be even happier once I restore all my app configs. Will update the description.

 

[nambuccaheadsau]

Think upgrade after upgrade degrades the speed somewhat. Being an old fellah I always use the erase and clean install method that we used back in the System 6, 7, 8 and 9 days.