Is There A Benefit Or Point Of Diminishing Returns With Adding Memory To A Mac?

K

Kurt Todoroff

Member
iMac, 27-inch, late 2009
Quad-Core i7 2.8GHz
1TB HD (655GB used, 314GB available)
8GB Memory
OS X 10.8.2

Parallels Desktop 8 For Mac
Windows XP Pro
Configuration Setting: 2 CPUs
Configuration Setting: 2,048 MB Memory

I use this iMac at my small business. The iMac restarts itself every morning at 6:00 AM. Typically, I launch eleven Mac applications when I arrive at my office one hour later. Then, I launch Parallels. I use all eleven applications frequently throughout the course of the day. Some days I use Parallels often (usually for Sage 50 accounting software), some days I use Parallels infrequently. Activity monitor shows almost no inactive memory, and about 500MB of free memory.

I am considering removing the 8GB of memory (4x 2GB) from this iMac and replacing it with 16GB of memory (4x 4GB) soon. The cost will be about $90. After I install the new memory, if I dedicate 2GB or 4GB or 6GB of additional memory to Parallels (4GB or 6GB or 8GB total memory), will this improve the performance of Parallels and Windows XPP? Has anyone run Parallels/Windows XPP in a configuration that is identical to what I propose? What were your results?

A colleague told me that the additional memory will not improve the performance of Parallels/Windows XPP because Windows XPP does not recognize more than 2GB of memory. I do not know if her assertion is correct, or relevant. She does not use Parallels.

Thank you.

Kurt Todoroff
 
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Hi,

I cannot help much concerning your configuration, but recently I tried similar and put more memory into my iMac running Win7 and Parallels8 (had 4GB (2 for Win7 and 2 for OS X) and put 8GB in addition). Ich was surprised that P8 does not accept more than 4GB for Win7. Now Win7 has 4OS X has 8GB and runs definitly smother than before.

spachner
 
Kurt Todoroff said:
A colleague told me that the additional memory will not improve the performance of Parallels/Windows XPP because Windows XPP does not recognize more than 2GB of memory. I do not know if her assertion is correct, or relevant. She does not use Parallels.
Click to expand...

This assertion is absolutely incorrect.

What is true thou, is that since you are most likely running 32 bit version of Windows XP you'll be limited to a maximum of 4 GB RAM. Giving more RAM will always help improve performance. But most importantly, are you experiencing some delays when accessing applications or data? If not, might not worth it to upgrade the RAM.
 
Stefan and Specimen,

Thank you for your prompt replies to my inquiry.

I am certain that my WXPP version is 32-bit. Unfortunately, I am unable to verify this at this moment.

Generally, Parallels and WXXP operate with respectable response and speed. Response and speed tend to suffer when I launch that "next" large Mac application such as iPhoto, and VM starts paging out to the hard drive. Clearly, I could solve the problem by running fewer Mac applications concurrently. But, this is not how I work. I could change my work methods, but $90 would be worth it to maintain my Mac processes. My comment about the "next" Mac application is another reason for justifying the potential memory upgrade. It does not occur often, but enough to become a bit irritating. So, the additional memory would solve two problems: the ability to launch additional Mac applications, and adding a bit of performance to Parallels/WXXP.

This being said, I could purchase the memory, increase Parallels' allocated memory from 2GB to 4GB, launch one or two additional Mac applications from time to time, and ostensibly not experience any response or speed impediments. Perhaps this sounds like I have already talked myself into this plan. I'm not sure. However, Stefan makes a compelling case for this plan with his experiences after he allocated 4GB of memory to Parallels/W7.

Again, I appreciate both of your responses very much.

Thank you.

Kurt Todoroff
 
If it starts paging out when you launch a mac application it's actually OS X that's paging and not the VM, so it's OS X that needs more RAM. Any way, if you are experiencing paging in whatever side, more RAM will reduce that, obviously.
 
Hello Specimen,

You are correct, and I misspoke. My reference to VM was virtual memory, not virtual machine. I should have been clearer. My apologies.

Nevertheless, thank you for assisting me. If you think of anything else, please post it.

Kurt Todoroff
 
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Oh, sorry about the VM thing, it hadn't crossed my mind you meant Virtual Memory.

Yes, one more thing, Stefan's configuration was a particularly bad case that was much improved with the RAM upgrade, but the reason why it was such a bad case is that OS X 'doesn't like' having just 2 GB, and neither does Windows 7 64 bit, these are both 64 bit OSs that need more RAM.

In fact, I don't recommend using Parallels (or any other VM app) on a computer with less than 6 GB RAM.

In your configuration you won't see such a dramatic improvement.
 
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Oh, of course. Excellent observation on Stefan's configuration. I had not considered that, either.

I am somewhat biased by a previous experience. My first Mac was a Mac IIx, which I still think of from time to time. I purchased it in 1989, and I really loved that machine. First computer, first love. Sort of like first aircraft, first love. It shipped with 4MB of memory, while the earlier Mac II shipped with only 1MB. My brother purchased an identical Mac IIx. The Mac IIx provided eight SIMM slots. It shipped with four of the slots populated with 1MB SIMMS and the other four slots empty. Once I installed Mac OS 7 (from 6.0.3) and started taking greater advantage of multitasking, it was running out of memory often. I found a bargain on memory, so he and I both upgraded from 4MB to 20MB at the same time. At the time, the $150 per 4MB SIMM seemed like a bargain. It was. We were immensely pleased with our 20MB Macs, and could do anything with them. I began to double the memory allocation in Get Info in my most important applications. This added a considerable amount of stability to daily operations. Even with ten applications running at double the memory allocation, the memory usage didn't even approach 20MB.

So, those fond memories (no pun intended) are biasing me towards upgrading my business iMac to 16GB. Fortunately, I don't use Parallels on my home iMac (mid-2010, 27-inch, Quad-Core i7, 8GB, 2TB), and the video card uses dedicated memory, not system memory. With twelve applications running, the memory usage barely exceeds 4GB.

Kurt Todoroff
 
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