RAM and Opteron combo...

[Adegan19]

For an Opteron 165, with intentions of overclocking, think its better to get pc 4000 and try to match the memory FSB to the CPU FSB, or go for pc3200, and get the lower latency? For example, 2gb dual channel OCZ Plat rev 2 pc3200, or G.Skill extreme 2gb at pc4000.

Also, can a properly Overclocked 165 match a Intel 955? hehe

 

[RallyMaster]

If you're overclocking, go with the GSKILL. That Opty will definitely hit at least a 250MHz FSB.

 

[Adegan19]

So there is a decent increase in performance for matching the memory FSB with the CPU FSB, or at least getting them close?

 

[wolfman11]

Here is an example I recently did with 3DMark2001 benchmark:

1) Opteron 146 @ 2.4, DDR400 effective (333 divider), command rate 2T = 24,046
2) Opteron 146 @ 2.4, DDR400 effective (333 divider), command rate 1T = 24,610
3) Opteron 146 @ 2.5, DDR340 effective (266 divider), command rate 1T = 24,294

The difference between #1 and #2 shows the impact of 1T vs 2T on command rate. Comparing #2 and #3 shows that the 30mhz drop in ram speed more than offsets the 100mhz increase in CPU speed.

In my case I found that while the CPU can go higher (I had it stable at 2.554 haven't gone any higher yet), the RAM dividers on my motherboard (ASUS A8N5X) are limiting how high I can overclock and still keep the ram as close to DDR400 as possible.

Right now the highest "sweet spot" I've found is 2.4, DDR400, command rate 1T.