Help Me Choose: Memory

Random Access Memory (RAM) — commonly known as system memory — is the temporary storehouse for the data flowing to and from your computer’s central processing unit (CPU). The most common forms of random access memory today, DRAM and SRAM, both require continual power to maintain their data. All else being equal, a system with more memory can:
- Deliver faster performance
- Handle more open files simultaneously
- Open larger files
- Work with more open applications simultaneously
Memory utilization is impacted by the operating system installed on your Dell™ OptiPlex™ system.
With 32-bit operating systems, such as the 32-bit version of Microsoft® Windows Vista®, the system may utilize up to 3.5GB of memory for system performance (out of 4GB), while the remaining 0.5GB is allocated to address space for various hardware components.
64-bit operating systems can utilize more than 4GB of system memory. The maximum memory available on Dell OptiPlex systems is up to 16GB. 64-bit operating systems require applications designed for 64-bit. Majority of business applications today are designed for 32-bit. However, the trend will continue toward 64-bit operating systems, as system memory plays a greater role in application performance.
Memory modules should be installed in pairs of matched sizes, speed and technology. Pairs of matched memory size are also referred to as dual-channel configurations, which yield the highest performance. If the memory modules are not installed in matched pairs, the computer will continue to operate, but with a slight reduction in performance.
Overview
The system you are configuring may or may not include all of the options listed here.
| If you want... | Choose... |
| The maximum amount of memory for 64-bit operating systems | 16GB memory |
| The ability to run simultaneous intensive business applications, with headroom for future operating systems and applications | 8GB memory |
| The ability to run multiple simultaneous office applications | 4GB memory |
| The ability to run business productivity applications | 2GB memory |
Recommendations
| OptiPlex™ | 990 | 790 | 390 |
| Number of DIMMs | 4 (2 on USFF) | 4 (2 on USFF) | 2 |
| 16GB* 1333MHz DDR3 Non-ECC SDRAM | ![]() | ![]() | ![]() |
| 8GB 1333MHz DDR3 Non-ECC SDRAM | ![]() | ![]() | ![]() |
| 4GB 1333MHz DDR3 Non-ECC SDRAM | ![]() | ![]() | ![]() |
| 3GB 1333MHz DDR3 Non-ECC SDRAM | ![]() | ![]() | ![]() |
| 2GB 1333MHz DDR3 Non-ECC SDRAM | ![]() | ![]() | ![]() |
Compare Side-by-Side

