Quote Originally Posted by furballi View Post
Just discovered a possible RAM anomaly with my Abit IP35-E/E4300 CPU combo. 1st pair of Kingston DDR2 800 (chips on both sides, 1GB x 2 with SPD 5-5-5-18/1.8V) is set at 5-4-4-9-2T in BIOS. Memory clock speed is 480MHz (overclocked CPU with 1:1.25 memory divider). Memtest 86+ V1.70 shows bandwidth of 5628MB/s.

Swapped these RAMs with 2nd pair of Kingston DDR2 800 (chips on one side, 512MB x 2 with SPD 5-5-5-18/1.8V). Same memory settings as the previous pair. Memtest 86+ V1.70 shows bandwidth of 5197MB/s.

Can a single-sided RAM module be slower than a dual-sided stick? Is the BIOS having issue with proper detection of the single-sided modules? Has anyone seen a similar drop in memory bandwidth with 4 sticks vs 2 sticks? I'm aware that adding more RAMs will place a higher load on the memory controller. That's why most rigs will drop from 1T to 2T with four modules in place.

my only guess is that you are using two disimilar stick sizes...one pair is a single sided and the other is double sided...the MCH probably is tweaked to handle the double sided over single sided memory sticks.