While attempting to install the latest version of MC Forge, I came upon a well documented failure, whereby the Gradle installer possessed insufficient memory to decompileMc.

After researching various previously reported errors, such as #324 on github, as well as checking the documentation,  I failed to correct the issue. I have created a file named "gradle.properties", saved using UTF8 and alternately located within my Forge src directory and ~/.grade/, containing the line: "org.gradle.jvmargs=-Xmx3G", but to no avail. Throughout this process gradle RAM usage did not exceed 512Mb, despite my efforts to the contrary. My computer posses 8 GB RAM. My logs can be found here , I hope someone here can guide me through a solution. Thanks in advance for your help, hope I did not miss anything obvious.

Upon further investigation I discovered a partial solution:

By first setting the environment variable "GRADLE_OPTS" to "-Xmx1024M" through the command: "set GRADLE_OPTS=-Xmx1024M" I was able to complete the decompilation process, however it took upwards of 20 minutes.

When attempting to assign more RAM to Gradle, I received the following error:

Error occurred during initialization of VM
Could not reserve enough space for 2097152KB object heap

I have a 64-bit OS, I have only JRE 64 bit, not the 32 bit.

Which I have, I meant only the 64 bit JRE, not the 32 bit JRE.

I am unsure as to how to do so, being extremely unfamiliar with the console.

Additionally, I have already successfully installed the forge MDK. I am simply leaving this thread open in hopes of a solution being found for future reference.

Here's the info you asked for:

java version "1.8.0_51"
Java (TM) SE Runtime Environment (build 1.8.0_51-b16) 
Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed-mode)

It SHOULD. But it doesnt.