High Sierra - Excessive RAM usage ?

You still didn’t tell us the spec of your DIMM, “old 64GB”, “new 64GB” means nothing here. Are they all RDIMM / UDIMM? What’s their latency? What’s their memory rank?...

If your new DIMM spec doesn’t match the old DIMM, there is a chance that you can’t boot with all of them installed.

 

And you have two cpus?

 

For your info, this is his post on the Mac Pro forum.

https://forums.macrumors.com/threads/why-when-i-added-memory.2110281/

 

I haven't read this thread thoroughly, but I installed High Sierra on a late model 2013 iMac 27 inch,
iMac14,2 which has 8Gb Ram installed. I found it so slow and unusable that I reinstalled El Capitan.

I tend to have 15-20 browser tabs open, total, using both Safari and Chrome. As well, I can have up to 20 terminal tabs open, where I am VPN'ed into the office. Excel spreadsheet but only a single spreadsheet, fairly simply spreadsheet. Also, typically Google mail and calendar as Safari tabs. And, normally, 1Password.

That's my typical usage. Unfortunately, I didn't try and diagnose the problem. When I went back to El Capitan, I was able to open at least double the above without any obvious problems.

 

--- Post Merged, Mar 31, 2018 ---

Hi I am not making a smart remark was just commenting I my own problems.
I have since found out the problem apparently Mac 5.1 desktops need all the same memory. and if you already have 64 Gb you do not want to buy it again.
so watch out, you can get 2RX4 & 4RX4, its no good trying to mix them
my computer would through a wobbler and not start going round in circles.

All the best Andy

 

Well, I don't know about all the people ranting here about 2GB RAM, but I noticed that, Cities Skylines: Green Cities DLC would not even open in High Sierra on my iMac with 8GB RAM. But then, I did a fresh install of Sierra, and guess what, it works flawlessly. The same thing I've noticed for another game, Transport Fever. So I think there is something with High Sierra and its RAM usage.

P.S. I am not a RAM Guru, I just state my findings is all...

Any comments?

 

I upgraded my 2011 MacBook Pro to 16Gb of RAM a few years ago, and I also notice that High Sierra uses much more of it than El Capitan did (I never went through Sierra). Using one of those Apps that tell you how much free RAM you have, I usully see only three or two (!) figures of free RAM when browsing the Net (typically Firefox and Opera).

 

Why would you use an app to let ok at RAM usage? NONE of them factor in macOS’s RAM management so all your getting is a useless number.

 

That's exactly what we want to see. The system can always effectively use all the resource, but not let them sit idle and doing nothing.

High Sierra is very good at using RAM to be the system cache. Unless your system use lots of SWAP and become very laggy. Only very little free RAM is a GOOD thing.

 

I have been reading more about this after posting my message, I guess my knowledge of the RAM mangement was not updated (after Sandboxing), or I just understood it plain wrong.

Thank you (both) very much for your replies.

 

Could be any number of factors stopping it running, have you asked the game developer if they claim compatibility with HS?

 

You question is SPOT ON as I face the same problem—-alleged experts telling me bad advice. ‘O/S High Sierra is a Resource Hog’ that eats 3.8GB RAM for breakfast . I’m pushing an obsolescent iMAC mid 2011 12.1 i5 quad core 2400S CPU with Sandy Bridge ChipSet. My 4GB DDR3 1333mHz 10600 CL9 barely works since my upgrade to HIGH SIERRA early 2018.

Since my i5 Quaddi runs true 64bit,
I should be able to drop in 32GB Ram (8GBx4 sticks) no problem yet the Ram retailer insisted my mid2011 iMAC could only read 4GB per slot. Your Question is legitimate because if the O/S needs around 8GB just to operate, multasking music downloads while running multiple programs will crash my Attentiyspan before it crashes my computer. How much ram is too much ram?

 

There's a reason that Apple generally only sells 8GB systems nowadays (although the 4GB spinner Mini is still lingering on death row).

I have a 2011 iMac which officially only supports 16GB but I've installed 32GB in it no issues. There's a difference between supported config and unsupported config, with this being an example.

 

Read Brad Moon ‘How to Install More Ram in your IMAC’ Forbes magazine 230829FEB2016 your i5 Quad Core Sandy Bridge is a true 64 bit machine which will accept/read 32GB Ram. I had one salesman argue with me that an iMac can only handle 4GB per slot for 16GB max—-he’s confusing our mid 2011 with last years early 2010 which with its dual core i3 is only a 32bit machine. Apples to Oranges!!!

 

SORRY for not getting back sooner. But yes you are right I had to get a certain type of memory and then buy the lot in one go trading in my old memory, other wise you have problems old memory will not recognise new memory but if you take the old out and put the new in you'r Mac will see it. Can be very confusing. All the best Andy