Adding 32GB of RAM hurt my Geekbench score by ~5%

[weaztek]

Last week, I had the brilliant idea to replace one of my paired 8GB chips in my 2018 Mac Mini i5 with a brand new Samsung 32GB chip of RAM. This would cost $132 with tools and bring me to 40GB which is more than enough for what I do which is mainly photo editing.

Well after installing the RAM my Geekbench score dropped about 5%. So I purchased Geekbench 5 because that can't be right can it? Got the same drop in GB5.

I know Geekbench scores aren't the end all but if anyone has any suggestions (other than adding another 32GB chip) that would be helpful.

 

[Stephen.R]

Your DIMMs aren't matched now, so you aren't getting the benefits of multi-channel memory.

 

[frou]

It will be running in Intel's so-called Flex mode, meaning the 32GB module will be partitioned into an 8GB fast region and a 24GB slightly slower region:

Single- and Multichannel Memory Modes

Guidelines for configuring your system memory to provide the best possible performance.

www.intel.co.uk

 

[weaztek]

Interesting.

I sure didn't guess in a million years that matched DIMMs were that much faster.

Nevertheless, with the 40GB I know memory intensive tasks like batch processing will have a big performance boost with the extra RAM.

 

[sigmadog]

Get another 32GB stick and please report the results.

 

[MacDuck]

FYI, This has been the case for years on 1,1 Mac Pros and later...they include a Memory Slot Utility to use for optimal configuration and performance. https://support.apple.com/en-us/HT205043 5% isn't much of a hit, but does come in handy when you need that extra bit of speed. 32 GB is nothing to sneeze at though. Let us know what happens!

 

[weaztek]

Well... I don't see myself dropping another $120 for a new chip just to get my performance up 5% again. I made a mistake thinking it would speed me up and I gotta live with it. At least until the price of 32GB RAM goes wayyyy down in price.

 

[hagjohn]

Yeah, never mix RAM chips.

 

[Stephen.R]

Get another 32GB stick and please report the results.

Is there some test you'd like to see on a 64GB machine? Or did you just want to confirm the perf difference of multi-channel?

 

[wardie]

Is there some test you'd like to see on a 64GB machine? Or did you just want to confirm the perf difference of multi-channel?

I think the point just was is you want the extra speed back of using dual channel memory you’ll need to put in another one of the same 32GB cards into the correct slot to pair it with your new one. Do you have 4 slots on that machine? If so you could have the original pair in dual channel, plus the extra one on its own.

 

[Stephen.R]

I think the point just was is you want the extra speed back of using dual channel memory you’ll need to put in another one of the same 32GB cards into the correct slot to pair it with your new one. Do you have 4 slots on that machine? If so you could have the original pair in dual channel, plus the extra one on its own.

I'm not sure if you have confused me with the OP or who I was replying to, I can't work out your response.

 

[weaztek]

After running a fresh install of Mojave for a few days I just ran GB5 again. I'm happy to say my machine did a little better and is now right in-line with the average scores of other Mini i5 machines.

 

[sigmadog]

Is there some test you'd like to see on a 64GB machine? Or did you just want to confirm the perf difference of multi-channel?

I'm planning on purchasing a Mini next year, an i7 with 64GB. I'm mildly curious if the properly configured RAM helps the overall performance and if so, how much; though the answer won't affect my purchase decision at this point.

But that was all secondary to my goal of spending the OP's hard-earned money, which seems to be the most popular game on these threads (especially over on the Mac Pro side). Heh.

 

[weaztek]

I don't think you'll get a Geekbench boost going from 16GB to 64GB. However, I do think you'll get a real life boost with any kind of paired RAM increases.

I'm not even doing anything and my machine is using a lot of RAM.

 

[sigmadog]

Yeah. I'm not too concerned. I mainly need the RAM because I usually have quite a few programs open while working on large files in Photoshop and Corel Painter. Looking forward to the purchase (and secretly hoping for an update beforehand, but not holding my breath).

 

[wardie]

I'm not sure if you have confused me with the OP or who I was replying to, I can't work out your response.

Meant OP sorry

 

[wardie]

I don't think you'll get a Geekbench boost going from 16GB to 64GB. However, I do think you'll get a real life boost with any kind of paired RAM increases.

I'm not even doing anything and my machine is using a lot of RAM.

Look at the macOS’s own memory pressure charts. The OS “uses” a lot of otherwise spare memory for caching which is not necessarily “in use” as such, depending on whether a 3rd party stats app knows that it may mis-report it as in use. No way you’ll be using c. 20GB RAM whilst doing nothing.

 

[ActionableMango]

I made a mistake thinking it would speed me up and I gotta live with it. At least until the price of 32GB RAM goes wayyyy down in price.

Not a mistake.

• The memory upgrade will speed you up enormously for any real world scenario where your prior RAM capacity would have been exceeded.
• Depending on how you use your computer, you may also see real world gain even without exceeding your old RAM capacity, simply from having more cache available to the OS.
• A 5% loss in Geekbench score due to memory bench results, actually translates to a 0% loss in almost every single real world use.

 

[weaztek]

Not a mistake.

• The memory upgrade will speed you up enormously for any real world scenario where your prior RAM capacity would have been exceeded.
• Depending on how you use your computer, you may also see real world gain even without exceeding your old RAM capacity, simply from having more cache available to the OS.
• A 5% loss in Geekbench score due to memory bench results, actually translates to a 0% loss in almost every single real world use.

Thanks. I'm feeling a lot better about the upgrade today.

Do you have 4 slots on that machine? If so you could have the original pair in dual channel, plus the extra one on its own.

It's just 2 slots on the Mini. I kept in an 8GB from the factory and added a Samsung 32GB chip. I hope I never have to crack this machine open again. Upgrade went ok, but there is a lot of fragile pins to unhook and hook back up to get it running.

 

[Fishrrman]

I upgraded the memory in my 2012 Mini from 4gb to 10gb by adding a single 8gb DIMM to the "top slot".
Never noticed a speed difference.

What "speed" is "lost" by having mis-matched DIMM sizes, is probably surpassed by eliminating VM page-outs, etc.

This is nothing to be concerned about.
Just.... use it ...!

 

[IowaLynn]

I wonder - in the interest go "science" only - how it would test and perform with just the one 32GB.

If I could have purchased 32GB for my SE/30... but 128MB was all she took........ an $100/MB