RAM Latency vs Frequency – Why It’s Important – ThioJoeTech

Understanding RAM Frequency: The Basics

This video provides a comprehensive explanation of RAM frequency and why it is a critical factor when purchasing or building a computer. Frequency refers to the number of cycles RAM can perform per second, often expressed in megahertz (MHz). A 3,000 MHz RAM, for example, can complete three billion operations per second. However, modern DDR (Double Data Rate) RAM operates at an effective clock rate that is twice its real clock rate, meaning a 3,000 MHz RAM effectively runs at 1,500 MHz while processing two data operations per cycle. The presenter highlights the significance of frequency in determining RAM performance but stresses that it is only one part of the equation.

The Role of Latency in RAM Performance

The video delves into the concept of CAS (Column Access Strobe) latency, which measures the delay in clock cycles between a CPU request and the completion of the operation by RAM. The presenter explains how latency interacts with frequency, emphasizing that higher frequency can offset higher latency because of shorter clock cycles. An example compares RAM with a lower frequency but shorter latency to RAM with higher frequency and longer latency, demonstrating that both can have identical performance. This segment clarifies that a balance between frequency and latency is essential to avoid overspending on RAM without gaining additional benefits.

Tools and Tips for Smarter RAM Purchases

To assist viewers in selecting the best RAM for their needs, the presenter provides a pre-made table and Excel spreadsheet, available in the video description. These tools allow users to calculate and compare the effective response times of various RAM options based on frequency and latency. Additionally, highlighted entries in the spreadsheet indicate the highest-performing DDR4 RAM currently available. The video concludes by urging viewers to prioritize finding RAM with the lowest possible latency at the highest frequency they can afford, offering practical advice for navigating the complexities of RAM specifications while building or upgrading a computer.

Key Takeaways:

• Ever wonder what the heck CAS Timings were? Well they’re more important than you think.
• Easy to understand hack: higher cl means less performance, to simplify the math just divide mhz with cl and the result is your performance score, where higher score means faster ram.
• Honestly, I don’t try to waste too much money on RAM, all this micro timing stuff doesn’t affect real world performance in any meaningful way for 99% of people, just buy some decent name-brand RAM with a lifetime warranty that’s compatible with your CPU and motherboard and you’re good.

“The shorter the clock cycle, which means the higher the frequency, the higher the delay.”

Reference:

• ThioJoeTech (YouTube Channel)