Wintec AMPX PC2-6400 CAS 5
If you'd prefer your "CAS 5" DDR2-800 modules with heat spreaders, Wintec's most basic AMPX models may suit your tastes a bit better. And it's not like you'll pay more for the addition of the heat spreaders, as these are actually up to $25 cheaper than the AMPO model.
Part number 3AXT6400C5-2048K contains all the required SPD values for broad compatibility, including an 800 MHz data rate at 5-5-5-16 timings, 533 MHz data rate at 4-4-4-11, and 400 MHz data rate at 3-3-3-8.
Wintec AMPX PC2-6400 CAS 4
Wintec really wanted to impress us with its range of low-cost parts, sending a third sub-$250 2 GB kit, this time rated at CAS 4. These low-latency AMPX modules are priced similarly to the standard latency AMPO versions at $210.
Wintec might have a lot of faith in the value of its Part Number 3AXT6400C4-2048K, but it's anything but "industry standard" stuff. Lacking DDR2-800 SPD values, it requires manually adjusting the BIOS to reach its rated speed. Low cost alone can't qualify it for a comparison of "cheap standard parts", but the performance charts will show how it stacks up to them.