Hi, I already installed compatibile 2400mhz ram when I bought it. I am wondering if switching to 3200Mhz will give extra speed? Will they really go at 3200? Will they go at 2666 (max intel speed)? If all used RAM slots have 3200Mhz RAM will it reach 3200Mhz? On Apple site I can find MINIMUM requirements (2400Mhz) but can't find a MAXIMUM that can be handled by the iMac. Any info?
iMac (Retina 5K, 27-inch, 2017), macOS High Sierra (10.13)
Well... faster RAM should... go faster. Obviously the machine has to handle it otherwise is just a useless and costly expense. Apple states that RAM needs to be MINIMUM 2400mhz and that lets you imagine you could go higher. As far as I understand these should be the rules...
- RAM should be always changed in couples. better should be that ALL 4 the rams are the same
- RAM will run at the speed of the lowest RAM (so if you have 2x 2400 AND 2x 3200 it will run at 2400)
- RAM will run at the maximum speed allowed by the motherboard chipset
I found info online that Intel MB have a maximum of 2.666mhz but can be (in the Win/PC world) overclocked to 3.000mhz. Probably not possible in the Mac world. I also found somebody that managed to get iMac 2017 to run at 2.666mhz (with 3.000mhz ram). This probably means that iMac 2017 handles a MINIMUM of 2.400mhz and a MAXIMUM of 2.666mhz (that is the maximum Intel chipset allows without overclocking)...
... But it would be nice to have an expert's word on this
Well, stating a minimum does not imply you could use something faster. It only means you should not use something slower.
But something to think about, neither Crucial nor MacSales sells memory kits for Macs that are faster than the rated speed.
The computer's memory bus controls how fast the RAM can run, not the other way around. With pre-Intel Macs, installing faster ram only meant the RAM clocked back to match the computer's memory bus speed. The computer still worked, but no faster.
Intel Macs tend to act badly when the RAM speed is a mismatch to the memory buss. So you could spend a lot of money on incompatible RAM to experience the joys of a unstable computer.
I guess you keep ignoring this part of the article…
Honestly, it doesn’t mean a lot. While faster, lower latency RAM will indeed increase the technical performance of your computer, it works at such a fundamental level that it’s almost impossible for us flesh-and-blood humans to actually appreciate the difference. It’s like the comparing Data from Star Trek and C3P0 from Star Wars—if one can calculate the odds of survival in one billionth of a second and the other takes two billionths, does it really matter which one you ask?
Faster RAM will give your PC better performance in certain specific benchmarks, but in terms of actual benefit to most users, having more RAM available is almost always better than having faster RAM. So if you’re on the fence about purchasing 8GB of DDR4 RAM with a speed rating of 3200 or 16GB of DDR4 RAM with a rating of 2400, go with the second option every time. It also means that overclocking RAM in the system BIOS is rarely worth the effort.
Intel Macs are PC based. MBs, CPUs, RAMs... this stuff doesn't change.
What Apple does is to select a particular configuration and optimise HW/SW for that one only.
When Apple states that MINIMUM I should put 2400mhz Ram is telling me that (1) I am allowed change RAM even regarding Mhz (2) I can put higher Mhz Ram (3) It is at least implying it might improve something
You can see what RAM you need from About This Mac > System Report > Memory.
The article says that it speeds up but to spend money on MORE ram instead than FASTER ram is more profitable in terms of results.. and I agree. Still my question is not about more ram and is not abut money problems... Just about speed.
So.. to Allan.. Do you know the speed of the iMac memory Bus... ? Is it 2400, 2666 (as many modern Intel MBs) or more?
I am not ignoring it... It says it improves very little... fine.. but it improves... So ... Can we discuss about the question or not? WHAT IS THE FASTEST RAM SUPPORTED BY IMAC 2017 ?
That is my question regardless of usefulness or cost of the operation.
Changing RAM is a perfectly legitimate operation for Apple.. Please check here:
I've never read anywhere where it's an advantage to install faster RAM than a machine is spec'd for.
Just to add, is why Crucial and MacSales do not sell higher speeds than recommended RAM for Macs.
Just to add, discussing unsuppoted modifications of Apple hardare is not allowed here.
Actually the article never mentions Macs at all nor does it say it improves a Mac's speed.
There is nothing wrong with installing more RAM.
If you want to install faster memory and ignore what's been explained, that's on you.
Good Luck.
MarcelloM1973 wrote:
This article explains some of the concepts I have summarised...How Does RAM Speed and Timing Affect My PC’s Performance?
About the article, it mentions in several places replacing the RAM with something faster is not really significant.
This article explains some of the concepts I have summarised...How Does RAM Speed and Timing Affect My PC’s Performance?
3200Mhz RAM in my 2017 5k i7 Mac?
