Choosing RAM 16-32GB?

Comments

• Reply 1 of 6

  spheric Posts: 2,564member

  July 14, 2018 11:41AM

  AFAIK, the only difference between the i9 and the i7 is clock speed. That's going to be pretty irrelevant for your usage. 
  
  RAM could possibly be a concern, but honestly, the internal SSD is so stupid fast that I haven't seen any problems with virtual memory on my 2016 Touchbar 15"… 
  
  OTOH, the rule of thumb for RAM is: Buy what you can afford. If your expense account can make room for the 32 GB upgrade, then do it. It will probably significantly increase resale value, as well, as the 32 GB machines are going to be comparatively rare. 
  
  
  

  
• Reply 2 of 6

  Marvin Posts: 15,326moderator

  July 14, 2018 12:18PM

  Balazsdansk said:

  I have decided to go for the 15" model. 
  1. Is it significant improvement between the new i9 vs, the better of the i7?
  
  2. The more important, is 32GB RAM notable difference in my workflow?
  
  I have my own business, I design with SketchUp, use Photoshop and Illustrator and lot of webpages on external screen simultaneously. 
  
  Or the maxed out 13" would bee just as good?
  

  The 15" model processor upgrades are usually not worth the extra, CPU tests are here:
  
  https://wccftech.com/intels-core-i9-8950hk-i7-8850h-and-i7-8750h-six-core-cpu-benchmarks-leaked-from-lenovo-laptops/
  https://www.msi.com/blog/msi-gt75-titan-got-over-86-performance-boost-with-intel-core-i9-8950HK
  
  The proper i9 test in the second link scores 1391 vs 1270/1288 for the i7s. The CPU boost is normally under 10% which isn't something you'd notice in real-world workflows. This is close to the 12-core Mac Pro, which scores around 1600. Roughly 80% of Mac Pro performance in a laptop is really good.
  
  The 13" model has a lower TDP and the performance is closer to the old 15" quad-core i7, click on the multi-core tab here:
  
  https://browser.geekbench.com/mac-benchmarks
  
  That CPU performance is perfectly ok for most tasks, the 15" will show more benefit for video encoding and rendering. 15" is about 70% faster.
  
  The 13" has a weaker GPU, < 1TFLOP, whereas the Radeon in the 15" is 1.5-2 TFLOP, you'd get double the performance from the dedicated GPU. The 13" also shares video memory with the CPU so the 15" gets 16GB plus 4GB of video memory, whereas the 13" is 16GB total.
  
  Whether you need 32GB of RAM depends on the workload. If you open the Activity Monitor and check the memory, if there is swap used then the computer ran out of memory. If it's multiple GBs and wasn't a one-off then more than 16GB would be useful. The OS has memory compression now so 16GB gives you around 24GB when it's able to properly compress unused memory. This is one of those cases where you'd typically know that you need 32GB and if you don't know, you likely don't need it. People who run virtual machines like to have more memory because each virtual instance uses multiple GBs of memory. It also helps with video compositing like After Effects and Da Vinci as it can keep more cached data in memory. Running Sketchup, Photoshop and Illustrator together could run out of 16GB if they were using over 4GB each but check if it's actually happening. The vast majority of 15" MBP buyers will get by just fine with 16GB, only a very small amount of users would benefit from 32GB, especially now that we have SSDs with 2GB/s write speeds because swapping in/out a few GB of memory can be done in a few seconds.
  
  I think you'd get by ok with the 13" but by the time you are at the quad core i7 and 16GB RAM, you're at $2299 and the 15" starts at $2399 with a 4GB dedicated GPU. I would recommend getting the entry 15" with however much storage you need (minimum 512GB) and the Radeon 560X for $100.

  
• Reply 3 of 6

  Balazsdansk Posts: 3member

  July 15, 2018 7:49AM

  Dear Marvin and Spheric, 
  
  Thank you for your feedback, indeed they are very informative. 
  
  Currently I used an Asus Zenbook Pro with 16GB of RAM and yesterday I have done all my usual things, but not excessive use. 
  
  When opening the task manager in the performance bar I have noticed that even thought my RAM use was around 11GB so leaving around 5 to spare but my CPU was 100% ALL the time, and after quitting SketchUp rendering mode it dropped. 
  In this case maybe I should concentrate on the i9 instead of the i7?
  
  Also in this case I had 5GB RAM to spare, is that sufficient or than maybe worth to look into the 32GB.
  
  I did chock me that the CPU use was so extreme and this was backed up by the fans doing so well that my pc also took off:)
  
  I appreciate all you help once again:)
  
  
• Reply 4 of 6

  Marvin Posts: 15,326moderator

  July 15, 2018 8:50AM

  Balazsdansk said:

  
  When opening the task manager in the performance bar I have noticed that even thought my RAM use was around 11GB so leaving around 5 to spare but my CPU was 100% ALL the time, and after quitting SketchUp rendering mode it dropped. 
  In this case maybe I should concentrate on the i9 instead of the i7?
  
  Also in this case I had 5GB RAM to spare, is that sufficient or than maybe worth to look into the 32GB.
  
  I did chock me that the CPU use was so extreme and this was backed up by the fans doing so well that my pc also took off:)
  

  The CPU will be 100% in any machine when an intensive task like rendering needs to be done. Even if you had a thousand computers, they would all run at 100% to get the job done as quickly as possible. If you get a new computer that's twice as fast, it won't run at 50% because it would take the same time to finish as the old computer, it would still run at 100% and take half the time. You could force it to only use half if you wanted to have the fans running less though.
  
  There's only 10% difference between the i9 and i7, it's not worth the upgrade cost and the i9 will likely run hotter. Having 5GB RAM spare is enough, the Mac system compresses memory so it gets even more but also consider if your workload will increase in future e.g try duplicating the size of your scene in Sketchup a few times, render it and check the memory usage of the Sketchup process. In a couple of years you might find that 16GB isn't enough the more complex your work gets. If the memory usage is still reasonable then stick with 16GB.

  
• Reply 5 of 6

  Balazsdansk Posts: 3member

  July 19, 2018 8:09PM

  So I would just like to get back to you with some gratitude:) 
  
  I am lucky enough to have received mine already yesterday and just opened it.
  
  Once have checked the Activity Monitor I have recognized that with the basic apps (illustrator, photoshop, word, a few tabs) open i used around 9-10GB, but zero is swapped.
  
  I am a little surprised that I have already reached so many "out of the box" and not even heavily using it. 
  
  What is your experience and is this normal?
  
  Thank you again if I can give opinion anything that would help you on future process don´t hesitate to write me:)
  
  Thank You 
  
  Balazs
  
• Reply 6 of 6

  Marvin Posts: 15,326moderator

  July 20, 2018 11:11PM

  Balazsdansk said:

  I am lucky enough to have received mine already yesterday and just opened it.
  
  Once have checked the Activity Monitor I have recognized that with the basic apps (illustrator, photoshop, word, a few tabs) open i used around 9-10GB, but zero is swapped.
  
  I am a little surprised that I have already reached so many "out of the box" and not even heavily using it. 
  
  What is your experience and is this normal?
  

  It's normal for it to use a lot by default, it will try to make the best use of the RAM and cache as many things as needed. It will start compressing memory when it runs low. The important thing is the swap size because that's what tells you when the memory needed was more than available. It doesn't have to be always zero but it should be zero most of the time.