I am installing the A-Data Vitesta EE DDR2-800+ memory kit into my AMD test system, which I have reverted back to stock settings to ensure the modules work as advertised at default speeds. This consists of a Biostar TForce 570 SLI board with an AMD 6400+ X2 Black Edition processor running at 200x16, or 3.2GHz. The modules had no problem booting at DDR2-800 with default timings and voltage, 5-5-5-18 and 1.9v vDIMM.
Here we can see that the JEDEC SPD settings do call for 5-5-5-18 at 1.8v however 1.9v is the lowest my motherboard will run the vDIMM at. There are two EPP settings specified on the modules as well, and the next step was to try them at the enhanced timings. Since my board does not support EPP, I had to manually adjust these down to 4-4-4-12. While the system would POST with these timing values, running Memtest86 to verify them at load would result in an instant reboot. I adjusted the vDIMM all the way up to 2.1v and still could not get them to run at the rated timings. I had to back the tRCD value to five in order to get them to complete a pass at 400MHz... well 402MHz to be exact, since my board runs the bus setting over by 1MHz.
With the modules finally stable at 4-5-4-12 and 2.1v it was time to try some overclocking to see how high they would go. I was able to get Memtest to complete several passes at 225 (450MHz), however this later turned out to be unstable and resulted in a blue screen while in Windows. 440MHz ended up being the max speed for the A-Data Vitesta EE modules at the 4-5-4-12 timing values. I tried relaxing the timings to 5-5-5-15 and even increased vDIMM as much as 2.4v in an effort to get a higher speed, however nothing over 440MHz was Windows load stable and in fact more than 2.1v actually decreased stability rather than helping.
Next I will run the A-Data modules through a battery of benchmark tests.