Is More Memory Better?

July 8, 2008 // 7:48 a.m.

Tags: #2gb #4gb #8gb #corsair #dhx #memory

Core Memory Performance

When memory latencies are equal, does a greater density DIMM provide better performance in 4GB versus 2GB, and does addressing four physical DIMMs in 8GB versus 4GB actually make it faster or slower?

Sisoft Sandra Unbuffered Memory Test

  • 2GB (2x1GB)
  • 4GB (2x2GB)
  • 4GB (4x1GB)
  • 8GB (4x2GB)
  • 6549.5
  • 6574.0
  • 6772.0
  • 6172.5
0
1000
2000
3000
4000
5000
6000
7000
MB/s (higher is better)

Everest Memory Performance Test

  • 2GB (2x1GB)
  • 4GB (2x2GB)
  • 4GB (4x1GB)
  • 8GB (4x2GB)
    • 6529.0
    • 7065.0
    • 6756.0
    • 6593.0
    • 7097.0
    • 6792.0
    • 6453.0
    • 7098.0
    • 6978.0
    • 6362.0
    • 7075.0
    • 5965.0
0
1000
2000
3000
4000
5000
6000
7000
MB/s (higher is better)
  • Read
  • Write
  • Copy

Straight up we can see both the twin DIMM sets of 2GB and 4GB memory have a raw performance that is very close together in both Everest and Sisoft Sandra. The 8GB set is notably slower though, mostly in copy performance according to Everest. Out of curiosity we also tested 4x1GB of memory in addition to the 2x2GB and found that the performance was notably better, especially in copy performance - the complete opposite to the 8GB set.

Memory Latency

  • 2GB (2x1GB)
  • 4GB (2x2GB)
  • 4GB (4x1GB)
  • 8GB (4x2GB)
    • 82.1
    • 95.0
    • 81.5
    • 95.0
    • 84.3
    • 97.0
    • 86.7
    • 97.0
0
25
50
75
100
Nanoseconds (lower is better)
  • Everest
  • Sisoft Sandra

As expected, four DIMMs means the memory latency of 4x1GB of memory is larger than 2x2GB. It's the same story with 4x2GB as well - at the same memory timings, things are just a touch slower.

It's worth noting that the 4x1GB of memory results were completely sporadic - within the same benchmark the times or frames per second were all over the place. We can only attribute this as a "feature" of the Asus BIOS and how it deals with 4 DIMMs, but having said that, running 4x2GB of memory worked far more consistently.
Discuss this in the forums

QUICK COMMENT

SUBSCRIBE TO OUR NEWSLETTER

WEEK IN REVIEW

TOP STORIES

SUGGESTED FOR YOU