1T and 2T (also known as command rate, possibly referred to with other terms): RAM will run faster with a command rate of 1T versus 2T. How much depends on the RAM, the platform/memory controller, and other factors, but if you can get your system stable with a command rate of 1T, do it. Note that some BIOSes do not support tweaking command rate. In the event that you can not adjust command rate, it is generally assuemed to be 2T.
For more reading:
http://forumz.tomshardware.com/hardware...mand-Rate-Explained-ftopict176007.html
Memory ratios: I'm going to assume you know what ratios are and do; just keep in mind that RAM speed is calculated a little bit differently on any K8 platform (s754, s939, s940, AM2, socket F). You use ratios to set your RAM to a different speed than your FSB/HTT so that you can put your RAM at a speed you like without necessarily setting your FSB/HTT to the same speed.
Example: Let's pretend I have a s939 X2-3800+ (with 10x CPU multi) I want to run at 3 ghz. I need 300 mhz HTT, but the standard 1:1 memory ratio will put my RAM at DDR600 speeds (300 mhz) which may exceed the maximum speed for my RAM. In fact, if I have cheap RAM that can't run reliably over 200 mhz, I'd be in serious trouble. So, I use the 3:2 ratio to run my memory at about 2/3rds (approxmiately) the speed of my HTT. That should set my memory to DDR400 (200 mhz) speeds which my chips would handle well enough. The result is I get to overclock my X2 without having to buy RAM that will run at DDR600 speeds. I would probably be bandwidth-limited in this scenario, but running my chip at 3 ghz with DDR400 RAM is still faster than running my chip at 2 ghz with DDR400 RAM.
Example 2: Let's pretend that I have a Core 2 Duo E6400 (8x CPU multi) that I want to overclock. I was planning on running the chip at 4 ghz by setting my FSB to 500 mhz, so I bought RAM certified to run at DDR2-1000 speeds (250 mhz actual, though most of us think of RAM running at DDR2-1000 speeds as running at 500 mhz, so we'll go with the latter for simplicity's sake). After overclocking, I find that the chip is limited in its ability to overclock, so it won't go past 3.2 ghz (400 mhz FSB). With the standard 1:1 memory ratio, my DDR2-1000 is running at DDR2-800 speeds (400 mhz, 200 mhz actual). In order to run the memory at its maximum rated speed (in order to get a little bit more performance, hopefully) I could use a 4:5 memory ratio which should run my memory at 5/4ths the speed of my FSB (approximately). With a 400 mhz FSB, the 4:5 memory ratio results in my memory running at DDR2-1000 speeds (500 mhz, 250 mhz actual). Using that ratio gives me a little bit extra performance, even though it doesn't make the CPU run any faster (it just makes RAM a bit less of a bottleneck). It would be better for me to run the chip at 4 ghz (500 mhz FSB) with a 1:1 memory ratio (DDR2-1000/500 mhz, 250 mhz actual), but since my chip can't get to 4 ghz, I may as well run my memory as fast as I can.
Facebook
Twitter