I'm confused as to what the LDT is and does on A64 kit. Now I've finally got the time I'm starting to OC my machine but would prefer to understand this so I can get the most out of it. I am aware that the HTT is essentially the "FSB" but what exactly is the LDT? And can I gain from pushing it up higher? I read somewhere that ideally (LDTxHTT)x2 should equal less than 1800, if so, why? I was quite happily climbing up through the MHz until my HTT got stuck at 275 and wouldn't behave properly past that, will a bit of properly understood LDT tweaking help me past this barrier? Any help appreciated.
it sets what the HTT Link operates at. If it goes over 1000 then you run into problems. Default is 5x. If you set it to 4x you should be able to run at 250FSB/HTT because 250x4 = 1000. Obviously if you are running 275x5 = 1375 OR 275x4 = 1100 you are going to run into problems with stability. 275x3 = 825 so that should be stable. Similar problems happen if you set it too low on most Nforce3 motherboards.
LDTxHTT=HT Speed. Also known as the HTT Multiplier. Like TMM said, you don't want the Hypertransport bus much over 1000mhz or else you can hit stability problems. In general, as close as you can get to 1000 without going over is safe although a little over is OK. Too low and you'll lose some performance but it's generally not a big difference unless you're talking under 700mhz or so.
