Exploring the performance impact of memory latency
 

THESE DAYS, SEEMINGLY every major memory module manufacturer is producing fancy low-latency DIMMs. These DIMMs are equipped with tricked-out heat spreaders and come in a variety of different colors, making them easy to pick out in a crowd. There's more to them than funky cosmetics, though. The most exotic low-latency DIMMs are rated to run at extremely tight 2-2-2-5 timings at 400MHz. Unfortunately, you'll pay a small fortune for the privilege. Low-latency modules cost close to twice as much as more pedestrian DIMMs, if not more.

Lower latencies are a good thing, of course, but how much can they really improve system performance? Are exotic, low-latency DIMMs worth the price premium? Read on as we explore the effects of memory latency on Athlon 64 performance in synthetic memory benchmarks, games, and real-world applications.

http://techreport.com/etc/2005q4/mem...y/index.x?pg=1

[M] review on the same subject -

http://www.madshrimps.be/?action=getarticle&articID=325

I found dropping from 1T to 2T using 4x512 has no noticeable performance impact except in Sandra bandwidth.