|
|
 |
|
|
Pages: 1
Memory Bandwidth vs. Latency Timings
(Click here to view the original thread with full colors/images)
Posted by: Ion Silverbolt
bonafidereviews.com goes into detail about memory timings and bandwidth.
Most DIMMs that run tight timings, such as certain PC3200 & PC3500 modules, have to run the memory at lower MHz than the FSB. However, when overclocking to extreme speeds these DIMMs are bandwidth limiting the processor. What I mean by this, is that when the processor requires a great deal of bandwidth, the CPU will have to wait for another clock cycle before being filled, as the memory is just not fast enough to keep up at the same pace. Having a large pool of bandwidth is great when you're working with applications that process a lot of raw data, such as Photoshop or databases for example.
The other point of view is that CAS2-rated PC3200 & 3500 memory can make up for the lack of bandwidth because the memory has a lower latency that in effect moves data between the CPU and memory faster. Programs that do not require a large amount of bandwidth tend to benefit more from quicker data transfers between the memory and the rest of the computer such as games or 3D applications.
While bandwidth is still very important to the Intel Pentium 4, it's not as important as it once was in the i845PE days of single channel memory controllers. Thanks to the i865PE/i875P's dual channel memory controller things are much brighter. On average, the system with the memory running at 400 MHz (5:4 memory divider enabled) with aggressive memory timings performed 2-3% faster than the system using high speed memory with loose timings. While that may not seem like a lot to most people, it can make a world of a difference to the enthusiast, especially if you're gunning for that high score in a clan match where every FPS counts. It seems as if all the large memory manufacturers/suppliers are afraid to lose face by not pumping out high speed memory modules with lax memory timings just so they can list them in their product lines. Many enthusiasts I know, tend to favor slower memory which allows them to run aggressive timings however.
|
|
|
|
|
