iMac performance problems Yosemite 10.10.3 or OTHER?

[swed02]

What the heck is wrong with my computer? First of all, I'm not smart. Computers are NOT my thing. I'm totally baffled. Over the past month or two my 2013 iMac 27" has been acting up. The internet is really slow, jumpy, buffering videos and slow downloads. Certain sites have video that won't even load. I've noticed sites with adds within the content (cnn.com, cnet, etc.) take longer to load those ads. I was thinking this might be caused by the os 10.10.3 update, but now I'm not so sure. Here's what I've done:

-used CleanMyMac to dump several 100 Gigs of junk off my computer
-ran speed tests with 28mb download and 1.8ish upload
-I have 24mb RAM, so I don't think that's the problem
-ran Kaspersky, made sure it's updated
-Activity Control never shows anything very high usage (above 30, unless I'm saving or downloading something)
-uninstalled and reinstalled Adobe Flash

All applications seem fine, but Photos is not as slick as advertised
-facebook is super jumpy
-website scroll is very poor
-video sites using flash seem buggy or like there's a virus or something
-AutoCAD 2013 works "fine" (no related problems, just older problems)
-Photoshop and Illustrator work well
-Google Chrome + Safari have same issues

This feels like a virus, but I don't have any proof. Can anyone help me determine if this is a Yosemite thing or a wifi thing, or a hardware thing, or a system thing, or something totally different? I'm out to sea without a paddle.

 

[WilliamG]

CNN videos are hit and miss on my iMac 5K. Sometimes they never load (Safari this is), and sometimes they're really jumpy.

YouTube is also hit and miss. A lot of the time the ad ends and the actual video never plays. A reload of the page and the same thing happens all over again.

I usually end up getting frustrated and switching to Chrome temporarily.

 

[valdikor]

I may not help you too much with this, especially considering the fact you have a very high end Mac and it should handle even more stress easily, but still:

Unless you're extremely paranoind and protective and/or you work with very sensitive data, you don't need to be using antivirus software on your Mac such as Kaspersky. Even in the Windows world the best protection against viruses is safe computing and common sense and it applies to Macs even more. It may very well be that the antivirus is eating up lots of system resources as it's running in the background and likely processing every file against mostly negligible threats. My advice would be to get rid of it. Actually I'm almost certain, at least from the data you provided, that it is the culprit.

Also: CleanMyMac. It is generally not advisable to use this kind of maintenance software on Macs, unless you're troubleshooting or really desperately want to free up free space. Although CleanMyMac is probably the cleanest and most honest not to mention good-looking software of this kind, Macs don't need any kind of routine maintenance. Things like app caches usually have a purpose. Cleaning software should be used only when troubles arise, although the developers will certainly tell you otherwise - take their advertising with a grain of salt.

Chrome has been known to be less than smooth and resource preserving on Macs in general, although its problems are limited to itself (if any) and should not interfere with Safari or the rest of the apps/system in any way.

 

[matreya]

I'd do a fresh reformat, re-install and restore from backup (you DO have backups right?)

CleanMyMac is a POS that does more damage than it solves, in my experience.

 

[marzer]

I second the system refresh. Backup up your system, format it, reload the OS and bring it up to date through system update, run it a bit to make sure everything runs well (web surfing, app responsiveness, over feel of performance, etc.) and if all seems well, restore your data.

I've never used Cleanmymac, but the fact it was able to remove SEVERAL 100 GIGS of anything leaves concern.