Best Jvm Arguments For Mac 4 Gb Ram
Posted By admin On 15.02.22I am a newbie to servers and management and I am trying to understand the relationship between RAM and JVM. Say, I have a server having 16 GB physical memory (RAM). I have an application running in Websphere. There are 4 application servers in Websphere each running the same application. We have allocated 2 GB JVM in each of the 4 application servers. I am assuming, 8 GB of RAM is consumed by the application as JVM and remaining 8 GB is free. In this case, is the free 8 GB utilized for someother purpose? Now is it possible to add 5 new application servers each allocated 2 B JVM. In other words, what is the relation between RAM and JVM. Can the sum of JVM added exceed the RAM?
Two great things about upgrading your PC memory are 1) that it’s cheap – especially when you consider how dramatically a new RAM stick or two improves your computer’s performance – and 2) it’s easy to add to your current computer setup. Then add the amount of RAM you would like to the JVM Arguments text box. For example if I wanted to run it with 1GB I would simply type -Xmx1G and the 1G will indicate 1GB of RAM. Xmx indicates the maximum RAM to allocate.
P.S. I am a newbie, please excuse if my question doesn't make sense. I am trying to understand how the application utilizes server memory (allocated as JVM).
2 Answers
In this case, is the free 8 GB utilized for someother purpose?
If at all possible, yes. Making RAM free is a pure cost for the OS -- it just has to make it used again in order to use it. Unless the OS has no choice, it will use the RAM for some other purpose. The most common use is data that has been recently read from, or written to, disk. By keeping it in memory, the OS avoids the hassle of having to make it free just to make it used again, and if the very same data is needed, it saves a disk read operation.
Now is it possible to add 5 new application servers each allocated 2 B JVM. In other words, what is the relation between RAM and JVM. Can the sum of JVM added exceed the RAM?
Sure. The JVM's are allocating virtual memory, not physical memory. The OS will assign physical memory to virtual memory as necessary and efficient. Modern operating systems can allow virtual memory consumption to significantly exceed physical memory. This may or may not lead to poor performance, depending on the working set size -- roughly how much of the virtual memory is actually accessed.
Mac 4 Pistol
David SchwartzDavid SchwartzWe have allocated 2 GB JVM in each of the 4 application servers.
I'd assume that you set the max heap size as 2 GB in each of the application servers? In that case, the size of your java process will actually be larger, as the java process will consists of the heap size 2 GB + the amount of native memory that the java process need. The amount of RAM the native memory the java process needs depends on the application, and unfortunately, cannot really be tuned. Therefore, when and if your application reaches the max heap of 2 GB, the size of your java process could be anywhere from 2.5 to 3.5 GB, possibly higher.
Therefore, keep this in mind if you have to allocate additional JVMs on your AIX box, so that it doesn't ran out of physical memory and starts paging.
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Best Jvm Arguments For Mac 4 Gb Ram
Learn how to identify your iMac, then find it below.
Mac 4 Gb Ram So-dimms Of 1333 Mhz Ddr3 Sdram
| iMac Model | Max. DRAM | User- Installable Slot | AASP- Installable Slot | Video/ VRAM | Notes |
|---|---|---|---|---|---|
| iMac (Retina 5K, 27-inch, 2019) | 64GB | 2666MHz DDR4 | 4GB or 8GB GDDR5 SDRAM | 5 | |
| iMac (Retina 4K, 21.5-inch, 2019) | 32GB | None | 2666MHz DDR4 (for i5 processor) 2400MHz DDR4 (for i3 processor) | 2GB, 4GB, or 8GB GDDR5 SDRAM | 3 |
| iMac (Retina 5K, 27-inch, 2017) | 64GB | 2400MHz DDR4 | 4GB or 8GB GDDR5 SDRAM | 5 | |
| iMac (Retina 4K, 21.5-inch, 2017) | 32GB | None | 2400MHz DDR4 | 2GB or 4GB GDDR5 SDRAM | 3 |
| iMac (21.5-inch, 2017) | 16GB | None | 2133MHz DDR4 | Intel Iris Plus Graphics 640 | 3 |
iMac (Retina 5K, 27-inch, Late 2015) | 32GB | 1867MHz DDR3 | 2GB or 4GB GDDR5 SDRAM | 4 | |
| iMac (Retina 4K, 21.5-inch, Late 2015) | 16GB | None | Intel Iris Pro Graphics 6200 | 6 | |
| iMac (21.5-inch, Late 2015) | 16GB | None | Intel Iris Pro Graphics 6000 | 6 | |
| iMac (Retina 5k, 27-inch, Mid 2015) | 32GB | 1600MHz DDR3 | 2GB GDDR5 SDRAM | 4 | |
iMac (Retina 5K, 27-inch, Late 2014) | 32GB | 1600MHz DDR3 | 2GB or 4GB GDDR5 SDRAM | 4 | |
| iMac (21.5-inch, Mid 2014) | 16GB | None | Intel HD Graphics 5000 | ||
| iMac (27-inch, Late 2013) | 32GB | PC3-12800 (1600) DDR3 204-pin SO-DIMM | 1GB GDDR5 SDRAM, | ||
| iMac (21.5-inch, Late 2013) | 16GB | None | PC3-12800 (1600) DDR3 204-pin SO-DIMM | Intel HD Graphics 4000 | |
| iMac (27-inch, Late 2012) | 32GB | PC3-12800 (1600) DDR3 204-pin SO-DIMM | 512MB GDDR5 SDRAM, | ||
| iMac (21.5-inch, Late 2012) | 16GB | None | PC3-12800 (1600) DDR3 204-pin SO-DIMM | 512MB GDDR5 SDRAM | |
| iMac (27-inch, Mid 2011) | 16GB | PC3-10600 (1333) DDR3 204-pin SO-DIMM | 512MB GDDR5 SDRAM and | ||
| iMac (21.5-inch, Mid 2011) | 16GB | PC3-10600 (1333) DDR3 204-pin SO-DIMM | 512MB GDDR5 SDRAM | ||
| iMac (27-inch, Mid 2010) | 16GB | PC3-10600 (1333) DDR3 204-pin SO-DIMM | 512MB GDDR3 SDRAM and | ||
| iMac (21.5-inch, Mid 2010) | 16GB | PC3-10600 (1333) DDR3 204-pin SO-DIMM | 256 MB up to 512MB GDDR3 SDRAM | ||
| iMac (Late 2009) | 16GB | PC3-8500 (1066) DDR3 204-pin SO-DIMM | 256 up to 512MB GDDR3 SDRAM | ||
| iMac (Mid 2009) | 4GB | PC3-8500 (1066) DDR3 204-pin SO-DIMM | 256 up to 512MB GDDR3 SDRAM | ||
| iMac (Early 2009) | 8GB | PC3-8500 (1066) DDR3 204-pin SO-DIMM | 256 up to 512MB GDDR3 SDRAM | ||
| iMac (Early 2008) | 4GB | PC2-6400 (800) DDR2 200-pin SO-DIMM | 128 or 256MB GDDR3 SDRAM | ||
| iMac (Mid 2007) | 4GB | PC2-5300 (667) DDR2 200-pin SO-DIMM | 128 or 256MB GDDR3 SDRAM | ||
| iMac (Late 2006) | 4GB | PC2-5300 (667) DDR2 200-pin SO-DIMM | 128MB GDDR3 SDRAM | 1 | |
| iMac (Mid 2006) and iMac (17-inch Late 2006 CD) | 2GB | PC2-5300 (667) DDR2 200-pin SO-DIMM | 64MB GDDR3 SDRAM | ||
| iMac (Early 2006) | 2GB | PC2-5300 (667) DDR2 200-pin SO-DIMM | 128MB GDDR3 SDRAM | ||
- Although iMac (Late 2006) accepts up to a 2GB SO-DIMM in each of its two memory slots, the computer only supports 3GB total memory.
- iMac (Late 2009), iMac (Mid 2010), and iMac (Mid 2011) have four SDRAM slots, each of which can accept a 2GB or 4GB SO-DIMM.
- These iMac models have no user-installable SDRAM slots. An Apple Authorized Service Provider (AASP) can install SDRAM in these computers.
- 27-inch iMac models introduced in 2012 through 2015 have four SDRAM slots, each of which can accept a 4GB or 8GB SO-DIMM.
- 27-inch iMac models introduced in 2017 and 2019 have four SDRAM slots, each of which can accept a 4GB, 8GB, or 16GB SO-DIMM.
- Learn more about integrated video on Intel-based Macs.
Learn more
Learn about integrated video on Intel-based Macs
Get more information about memory and specific iMac models: