Hi gerbils. I was playing around with my PC for the past few days trying to troubleshoot choppy gameplay. While I was at it I've realized that my PC was running slower when only 2 of the 4 DIMM slots were populated. This was also chronicled in my recent post about this problem (General Hardware > PC Becoming Slow). Since I believe this deserves a separate thread under RAM, here I am with this new thread.
My specs are as follows: AMD Phenom II X3 720 (unlocked to X4, no OC), MSI 785GM-E65, 4GB or 8GB of Apacer DDR3-1333, AMD HD4670 512MB, 1TB Hitachi HDD, 2 x LG ODDs, ACBel 600+W PSU.
I'm using Passmark (Memory Mark) to test the RAM's performance. When only 2 DIMMs are filled, I get a score of around 800 (Dual Channel mode, as reported by CPU-Z and also following the manual's recommendation for Dual Channel operation). With all 4 DIMM slots filled, the score jumps to about 1,200. I'd hate to think that memory performance is actually lower with fewer DIMMs installed.
I also tested 2 x 4GB DDR3-1333 (instead of 2 x 2GB DDR3-1333) from another PC and I still got low scores of ~800 in Passmark.
AMD FX-8350 / Gigabyte 990FXA-UD3 (rev. 4) / 2 x G.Skill Ripjaws 4GB DDR3-1866 / AMD HD7770 1GB / TP-Link WN723N USB Wifi-N / Samsung 840 EVO 250GB / Hitachi 7K1000.C 1TB / LG ODD / Cooler Master GX650 / Aerocool VS3 / LG W2252TQ / Win7 64-bit