Quote Originally Posted by dinos22 View Post
have you pushed your RAM more
I may bump up Vdimm if I know the mfr of these chips. Very strange logo. RAM is rated at 1.8V.

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.

Not sure why the speed of the 2nd pair (512 x 2) is lower than the first pair (1GB x 2) when all other parameters in BIOS are the same. Both pair are stable up to a minimum of 576MHz.

Memtest reports a bandwidth of 4358MB/s when all four sticks are added to the MB (dual channel...1+3, 2+4).

Went back to BIOS and manually set the RAM settings to 5-4-4-9-30-3-4-3-4 to remove any AUTO RAM dectection mode. Re-tested both pairs. Still no change with the bandwidth numbers. BTW, all sticks passed Memtest86+.

Booted to Windows to check the performance of the RAMs using Super Pi. The 1st pair (higher bandwidth per Memtest) yields marginally faster time.

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.