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Will someone please help an OC n00b?

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DragonTattooz

Member
Joined
Aug 29, 2005
Admittedly, I don't know diddly about OCing. Ok, now we've gotten that out of the way... I really want to learn this stuff. I've read the stickies, I've Googled for hours, I've been made fun of and laughed at. There are just some things that are not clearly explained. For example, I read the sticky from Drissler (sp?) about OCing memory, but in the section on how to OC the memory, it really doesn't tell you HOW to OC the memory.

As my sig says, I have the PC4000 CB memory. But, it doesn't run at DDR500, it runs at DDR400 with the memory clock on auto. If I run it at 200MHz, it indicates DDR400, which is what you would expect to see, however, if I change the memory clock to 250MHz, it actually drops it to DDR260 according to Memtest- the weird thing is that the bootup screen indicates DDR500. I am only running one stick right now because my other one is bad. I'm running the system completely barebones- CPU, Vid card, one stick of memory.

Now, my understanding is that with an AMD system the memory has to run at the same speed as the FSB- syncronous. So, I went into the BIOS and set the memory to 250MHz and the FSB to 250 MHZ, and that doesn't work. I have the BIOS set to boot into Memtest and it would get to the point where it would normally enter Memtest, but then it just reboots, so I obviously did something wrong.

Can someone tell me what LDT is? As in LDT/FSB frequency ratio?

Also, I have read about the multipliers and OCing, but I'm not sure where the multipliers are in the BIOS.

I actually have a lot more questions about multipliers and the whole synchronous operation issue. I think I'm not understanding that correctly because it's pretty obvious that people are not running their FSB and memory at the same frequency.
 

RedDragonXXX

Senior RAM Pornographer
Joined
Mar 3, 2005
Location
Jacksonville, FL
First off make sure that you have your divider set to 200 or otherwise known as 1:1 ratio. As indicated this will run your RAM at exact same clock as your HTT, so if you have HTT set to 250 with 1:1 divider your RAM will be at 250 as well.

Also, your CPU may be bottlenecking you. When rasing HTT did you leave your CPU at default multiplier and Vcore? If yes that could have been the cause of your problem. My suggestion if you want to see how far you can go with your RAM first determine how far your CPU can go at certain Vcore after you establish that drop down your multiplier and let it rip, but be sure to take it slow and raise only 5MHz at a time. Your RAM timings and Vdimm will play big part as well, which in your case you got Balistix aka Micron 5BD's which scale nicely with 3-3-3-8 timings and up to 3.1Vdimm. I would suggest that you take it slow on Vdimm especially if you aren't active cooling your RAM because Balistix are known to get realy hot.

LTD is similar to multiplier and it determines your FSB. It goes up to 5x and it coresponds with HTT. So if you have HTT set to 250 and LTD at 3 it will equal to 750MHz. Your FSB should never exceed 1000MHz if you want to have stable system so determine how high your LTD should be based on your HTT.

Hope that helps :thup:
 
OP
D

DragonTattooz

Member
Joined
Aug 29, 2005
Thank you fellow Dragon. Yes, that does help.

HTT and FSB are the same thing, right?

At the moment I'm really not trying to OC, I'm just trying to figure out why my RAM is running @ DDR400 instead of DDR500. Don't get me wrong, I want to OC this rig, that's why I bought the components that I bought. But I wasn't planning on real OCing until I have it fully up and running- which should be today.