When you upgrade your computer’s hardware, it is a given that you expect a boost in performance, but sometimes you get an unexpectedly significant increase beyond what you counted on. Today’s SuperUser Q&A post helps a confused, but happy gamer understand how he lucked out when he upgraded his computer’s memory.
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
The Question
SuperUser reader CyberGhostx1 wants to understand how adding memory significantly increased the gaming performance for his computer’s AMD APU:
The additional boost in game performance is definitely a treat, but how did a simple memory upgrade make such a difference this time?
System Specs
CPU: AMD A10-6790K 4. 0 GHz GPU: AMD Radeon HD 8670D 1GB (integrated GPU) RAM: 2 x Team 4GB 1600 DDR3 = 8 GB
Of course, I am using a 64-bit OS to make use of my 8 GB of memory, but my question is: Before I installed the additional 4 GB of RAM, games like Mafia II ran (at the highest settings) at an average of 22 FPS. After I installed the additional RAM, I noticed a very decent increase to 40 FPS even though the game did not appear to use more than 4 GB of RAM.
What is the secret behind this?
The Answer
SuperUser contributors DragonLord and Ben Richards have the answer for us. First up, DragonLord:
Followed by the answer from Ben Richards:
When you upgraded your system’s memory, you added a second memory module. With two modules, your memory now runs in dual-channel mode, doubling memory bandwidth and dramatically increasing performance as a result. Faster RAM (at least DDR3-1866, preferably DDR3-2100+) will similarly increase performance as well.
In addition, more memory means your system can pre-load more texture data into RAM, reducing the need to access the disk and increasing performance. However, this is less of a factor than the increased memory bandwidth.
To show how important memory bandwidth is for AMD APUs, websites such as Tom’s Hardware and PC Perspective have found that APU performance can increase with memory bandwidth up to at least DDR3-2100.
Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.
The reason the RAM upgrade sped things up for your game is likely because of texture resource swapping. With more RAM available overall, that means more texture data is able to be loaded and kept in RAM longer. When you have all your memory allocated, and your operating system needs more to work with for a task right now, it will find allocated memory that has not been used recently, save the contents to your disk, and then re-allocate the memory for that task. Once that data is needed again, it will swap it back from the disk into RAM. This swapping takes a long time (relatively).
You were likely swapping a lot on texture data. When you upgraded your RAM, you provided more space for textures to be stored, which means less memory swapping, which then translates into a higher FPS.
