Debunking a Myth: DDR3 RAM vs. ECC Memory Performance

Recently, a workstation PC was reviewed on a well-known PC hardware site that included a Quadro video card, but no ECC memory. In the comment section of that review, a heated discussion occurred with different readers arguing about whether the lack of ECC RAM was a good or bad thing in a workstation. One side argued that ECC is great for workstations since it is much more stable (as explained in this Advantages of ECC Memory article) and stability is very high priority for a workstation. The other side claimed that ECC memory was slower than non-ECC so it wasn't the right choice for a high-end workstation where performance was a priority.

Much of the ECC versus Non-ECC argument comes down to speed versus reliability. The reliability argument at least is easy to validate; over the last 12 months we've seen a tiny .09% failure rate with ECC memory compared to a .6% failure rate for standard memory. As for performance, we've actually tested RAM performance in the past and found that faster memory does not always equate to better performance since the RAM is often not the bottleneck.

Editor's Note:
This guest article by Matt Bach was originally published on the Puget blog. Matt has been with Puget since the early days working in the various subsets of production and is currently the head of Puget Labs.

However, the expected performance drop of ECC RAM is slightly different than what we saw in those tests since it's due to the extra error checking process rather than slower timings or frequency. In fact, Crucial has a statement on their knowledge base that ECC memory will decrease your computer's performance by about 2% compared to standard memory.

Alas, to settle the question of whether ECC actually lowers system performance we ran a series of benchmarks with standard RAM, ECC RAM, and Registered ECC RAM that all run at the exact same frequency, timings, and voltage.

Test Setup

To examine the performance of the three kinds of memory, we used the following hardware: