Lab Update - DDR2 vs DDR3 performance with the AMD AM3 Processors

Update - Our first comparison article will go live on 3/10.

Talk about a labor of love. Our planned " quick update" on DDR2 versus DDR3 performance with the new AM3 processors has turned into a week of headaches, anxiety, and frustration. That said, it has actually been enjoyable for the most part as I have been off playing memory detective. Trying to find optimal and stable settings on our AM3 boards has been like playing a good game of hide and seek. Of course this hide and seek game has our AM3 platform hiding in New York and I started seeking for it and the answers to our problems in Alaska.

After several misfires with early boards, processors, and BIOS releases we are on the right track now. New retail boards and processors just arrived along with a slew of BIOS releases this past weekend with more to come tonight. I think we are at the point of starting the "official" benchmark process now and hopefully we will have our first results up this week.

After a few stop and go marathon testing sessions this last week, our preliminary opinion about DDR2 and DDR3 performance being a wash for the most point still stands, at least with stock speeds and standard memory settings. Once you crank up the processor and Northbridge speeds, lower the memory timings, and throw in some decent cooling, then DDR3 starts to make a small but measurable difference in a few benchmarks. That should not be a surprise as the same tuning process holds true for DDR2. However, we see a little better scaling with DDR3 in certain applications when overclocking. Something we could not determine early on without having retail product and a BIOS that no longer throws a roadblock in our way every time we make a simple change.

The recurring theme that has made testing difficult is that our board, chipset, and BIOS combinations favor different memory modules, voltages, and clock speeds. Unlike the AM2+ products, our clock speed variations between boards vary widely at this time with one setup heavily favoring the newer low voltage (1.5V~1.65V) modules recommended for the i7 platform and the next one running optimally with the higher voltage (1.8V~2.0V) DDR3 modules released last year.

We are still testing various combinations but we have reached DDR3-1866 with 2x1GB product, while a 2x2GB setup on the same board is lucky to do DDR3-1520. We move to the next board and our same 2x1GB kit might reach 1700, yet our 2x2GB will easily run at DDR3-1600. However, memory speed is not always the answer and we have settled in at the officially supported DDR3-1333 clock speed for the time being. The difference maker is that we can run CAS5 timings with a decent set of DDR3 on 1.65V and raise Northbridge speed to 2800MHz~3000MHz on the Phenom II X3 720BE. This combination has proved to be the best performing one so far, but at the expense of a little processor speed (75MHz) up top.

Speaking of the 720BE processor, I have to say this little jewel is currently my favorite bang for the buck processor. I have had an absolute blast testing this processor and when overclocked, it truly takes on a "devil with a blue dress" persona. I highly suggest you take a serious look at this processor if you are in the market for an upgrade right now. Anyway, we will be back shortly with our first results and some additional details about the AM3 platform.