AMD AM3 Memory Performance Guide
Posted on: 07/12/2009 05:00 AM
Today we are looking at how various DDR3 memory frequencies and timings affect the AM3 platform in terms of performance. This guide is intended to help users put AM3 memory performance into perspective, helping them to choose exactly what kind of DDR3 memory they need...
Given current pricing, those looking to build either a budget or high-end computer based on an AMD processor, might as well invest in the new AM3 platform. Just a few months ago we were suggesting budget builders avoid the AM3 platform as it offers no real performance advantage when compared to a similar AM2+ setup, and more importantly it forces users upon the more expensive DDR3 memory standard.
However it is now possible to purchase a decent DDR3-1333 memory kit with a 4GB capacity for roughly $65 US, while a decent DDR2-1066 kit is just $15 US cheaper. The improved DDR3 pricing has helped to make the AM3 platform a more attractive option now, and although it still fails to deliver any real performance benefits, it does have one important advantage, and that is its upgrade path.
The AM2+ platform is nearing the end of its life, and while a Phenom II X4 940 processor will keep most users smiling for some time to come yet, chances are the next upgrade will see you replace not only the processor but also the memory and motherboard, making for quite an expensive upgrade venture.
Therefore those that make the move to the AM3 platform now, rather than invest in the slightly cheaper AM2+ platform, will be ensuring that they have a feasible means of upgrading down the track. Both AM2+ and AM3 motherboards use the same chipsets, and therefore users can expect to pay roughly the same price regardless of the supporting socket.
Back when building an AMD computer based on the AM2+ platform was the smart thing to do, a decent DDR2-1066 memory kit was the way to go. The price difference between 800MHz and 1066MHz DDR2 memory was trivial, while the higher clocked memory did deliver a slight performance advantage.
However when it comes to DDR3 memory there tends to be quite a large variance in frequency and even timings. For example, a 4GB DDR3-1066 kit can be purchased for $60 US supporting CAS7 timings, while for just $75 US it is possible to purchase a 4GB kit that can work at 1600MHz with CAS8 timings. If you want to spend even more money you can get DDR3-1600 memory that can work at even tighter timings.
The question is, to get the most out of your AM3 processor, what kind of memory do you need exactly? Is low-latency 1066MHz memory the way to go, or is high-speed memory with less aggressive timings a smarter option? With such a small difference in price it could make more sense to just go with the high-speed memory. However if it turns out that lower clocked memory with tighter timings is just as fast or faster, then saving a few dollars where you can would be the smartest option.
In order to try and determine what is the best course of action to take here, we have paired AMD’s flagship AM3 processor, being the Phenom II X4 955 Black Edition, with the ASUS M4A79T Deluxe motherboard and two sticks of Crucial Ballistix Tracer 4GB DDR3 memory. This low-latency memory is designed to work at 1333MHz, though it can handle frequencies well beyond 1600MHz with respectable timings.
Printed from Legion Hardware (http://www.legionhardware.com/articles_pages/amd_am3_memory_performance_guide,1.html)