Overclocking for the first time

[akassasin]

Ive read through a few guides on these forums but I'm still pretty confused about exactly how to overclock my system. The one thing I understand is that the FSB/HTT affects both memory and CPU speed.

I went into my BIOS and upped the "CPU Frequency" (im assuming this is the FSB/HTT) from 200 to 220 and upped the RAM voltage to 2.7 (from "default").
Im now running at 2.42 ghz cpu and 458 mhz RAM frequency.

I'm not interested in pushing my system to the max right away, I want to take it slow for now.
What I am interested in now is learning how to optimize my memory speed/timings with my current 2.42 ghz overclock.

I notice people listing x-x-x-x numbers for their RAM timings. Not sure what any of this means but I noticed some numbers in my BIOS that I'm assuming are what people are referring to.

Heres what I have listed under DRAM config:

Memclock Index Value: 200 Mhz

CAS# Latency (TCL) - 2.5
Min RAS# active time (Tras) - 8T
RAS# to CAS# Delay (Trcd) - 4T
Row precharge time (TRP) - 2T

Basically all I've done so far is upped the HTT/FSB and RAM voltage - not sure what to do next.
Any help is greatly appreciated.

thanks!

 

[Traire]

Unlike Pentium and older AMD systems, You dont need to run the memroy at synchronous speeds with the A64 CPU. You will be able to push your CPU much higher by using a memory divider and keeping your memory running ~200mhz.

For memory timings, when people list out their memory as x-x-x-x, that means: CAS-TRCD-TRP-TRAS. So your memory is running at timings of 2.5-4-2-8, which is not too bad. How much you can fiddle with your timings will depend on the quality of the memory. If want to try fiddling with your timings, try to get 2-3-2-7 at 200mhz. If you increase the memory speed much beyond 220mhz, getting your timings down will be much more difficult. The performance increases from doing this are also fairly minor.

You would get more noticeable results just increasing the CPU speed, and leaving the memory running at stock speed and timings. Though if your pushing your system the the limits, I'd do more reading on how memory system works first.

 

[akassasin]

Originally posted by: Traire
You will be able to push your CPU much higher by using a memory divider and keeping your memory running ~200mhz.

What is a memory divider?
these?

200 is 1:1, 1/1, or 1.00
166 is 6:5, 5/6, or 0.83
133 is 3:2, 2/3, or 0.67
100 is 2:1, 1/2, or 0.50


Also, I keep reading about people changing there HT multiplier to 4x, but I dont see anything like that in my BIOS.

 

[akassasin]

BUMP

 

[Jeff7181]

I think the HTT multiplier might be called LDT on some motherboards, so look for that too.

For the most part, lower timings are better. It's been shown previously that a Tras setting of 11 works better for Athlon XP and nForce2 setups... I don't recall, but I think that also holds true for the Athlon-64 processors. I've never tested it myself, so I can't say for sure. Maybe I will test it.

Anyway... increasing voltages should ONLY be done when you find your settings are unstable. Don't just increase voltage for the hell of it unless you're going to say, I'm willing to run 1.500 volts max and get the highest speed possible. Then go ahead and set it to 1.500 and when you find your max stable overclock, then back the voltage down a bit and see if you can maintain stability at that speed with less voltage.

Other than that... the "Quick and dirty A64 clocking guide" at the top of this forum should give you all the information/instruction you need to overclock. If something there is unclear, ask about it there and I'm sure Zebo will be happy to clarify anything that hasn't been clarified already.

 

[Traire]

Originally posted by: Jeff7181
For the most part, lower timings are better. It's been shown previously that a Tras setting of 11 works better for Athlon XP and nForce2 setups... I don't recall, but I think that also holds true for the Athlon-64 processors. I've never tested it myself, so I can't say for sure. Maybe I will test it.

6-8 is the sweet spot for TRAS on A64