Generation Change: Eight Motherboards For The Athlon 64

Main Memory: Don't Go For The First Best Thing

A solid main memory system is more critical than ever. Whereas good mobos featuring memory modules without cleanly programmed SPD EPROM have generally set timings far back up to now, problems could arise with souped up systems and fast memory (DDR400 or even more). That’s why we limited ourselves to one memory type that has served us reliably and well over the past few months (see illustrations).

We weren’t able to run the Corsair PC3200 XMS memory used in the test, released for 6-3-2 and CAS latency (CL) 2.0, at the ideal timings of 2-6-2-2. Timings slower than those specified inevitably resulted in a complete crash after a while.

Up until just a few months ago, various brand name modules that were released for CAS latency 2.0 but not for other low values could actually be run faster on the odd mainboard without problems.

That leads to the following conclusion : the memory makers have their production so much under control that today’s minimal specified timings basically can’t go any lower at high clock frequencies. There’s not a lot of leeway left at high clock speeds of over 200 MHz (PC3200 and higher).

That’s why we have to advise against no name modules, since the timings they specify if any timing parameters are given at all are sometimes just ballpark figures. In conjunction with a system that relies on precision this could result in some unpleasant problems, some of which may be very difficult to isolate and could lead to a lot of headache.