K8N Neo2 and 3500+ AMD 64, Overclocking?

[jackburton2004]

I'm trying to overlock my memory without overclocking the CPU, but don't seem able to. I can alter the CPU ratio, but the memory will never go past 200 no matter what I do. I can only overclock the memory if I keep the ratio at the default of 11, but then the CPU overlocks and I can't get the RAM as high as I need to because of that. I bought the OCZ Gold Rev.3 with OC it in mind, but is this only achievable with the FX CPU? Because of the slower timings, do you think I should return the memory and get a 2-2-2 set?

 

[jpeyton]

Lower the LDT ratio (HT ratio) to 3x or 4x.

 

[imported_thomase]

Can't overclock memory without overclocking CPU unless you lower the multiplier. Memory speed is derived from CPU clock. The smallest possible divider (highest memory speed) is ALWAYS equal to the CPU multiplier. For example, for a CPU mult of 11, the minimum divider (used for 200MHz setting) is 11, 2200/11=200. You need to lower the CPU multiplier while overclocking FSB if you want to overclock memory without overclocking CPU Also, OCZ Gold Rev 3. is 466 stock but may get up to 533. Thats would be 233fsb/2566cpu or 266fsb/2933cpu at your default multi of 11. 2566 is doable but 2933 seems like a stretch. If you planned on running memory too much higher than 233MHz, I think you are paying for a higher multi than you need (assuming that a 3200+ or 3000+ is capable of the same overclocks as the 3500+). Also, as jpeyton says, lower the LDT ratio from 5x to 4x if you are overclocking to <= 250 fsb. If you go over 250 fsb, you may need to lower the LDT ratio again to 3x. You should keep FSBxLDT under 1000 if you are testing to see how far you memory and CPU go.

Regarding memory latency, it all depends on what the total latency for the address to get out and the data to get back in to the CPU core. I'm not familiar with these characteristics but the info must be out there. For example, if you are talking about CL2.5 vs CL3 that is 1 clock tick at 200MHz or 4 nanoseconds. If the total latency through the memory and the memory controller is significantly more than this, increasing the FSB speed (memory and memory controller speed) should more than make up for increasing the CL from 2.5 to 3 because each clock tick is that much shorter. For example say we have 50ns latency back and forth through the memory controller. Difference between CL2.5 and CL3 is 2.5 ns. If you increase to CL3 that changes latency to 55ns, but if you also change FSB to 233, the total latency is reduced to ~47 ns.

Actually, my guess for memory latency doesn't seem to be that far off according to http://www.xbitlabs.com/articl...y/athlon64-3200_6.html
90 CPU cycles is ~41ns and 103 CPU cycles is ~47 ns. That change of I would expect increasing CL by .5 and RCD by 1 increases latency by about 7.5 ns (not far off). If a majory of the latency reported in this article is in the memory and memory controller, I would suspect that upping the fsb to 250 ~ 266 will more than make up for looser timing.

 

[jackburton2004]

Problem is the LDT ratio selection freezes everytime I hit enter on it, not sure why. Any ideas? It freezes everytime with everything on default. I can't do anything when I select it, I have to hit reset.

 

[Dolph Dorcas]

I had the same problem of my computer locking up when I tried to change the LDT ratio in the BIOS. (I'm running BIOS version 1.3.) I worked around it by typing in a "4" rather than hitting enter.

 

[popcorn731]

I have a K8N Neo2 Platnium &amp; AMD 3500+, I have had the same probs with the bios HT locking up when trying to view it. What you need to is reboot your system, go to bios and then go LOAD BIOS DEFUALTS. I believe it is located on the right side of the Bios menu screen. Just a copy below the cell menu. Hit enter on <load bios system defaults>. Then accept setting by answering <yes> then press <enter>. Once you reboot go back into bios and goto cell menu. You should be able to view you HT options 1-5 again. What happens is sometime the bios will freeze up on loading bad parameters in the bios and instead of having to reset bios with you <CMOS> overide pin it will still allow you to go into bios. But for some strange reason you can get partial access to the bios but with some missing options. Like your raid array or most often the HT options.

I am having problems getting past the 2390 in oc. If anyone can help that will be great!

AMD 3500+
MSI K8N Neo2 Platnuim
Gainward Nvidia 5900XT oc:599/918 (Omegadrivers.net)
Thermaltake Heatpipe 101 &amp; 90mm UFO
Corsair Value Ram 2x512 DUAL CHANNEL ddr3200, 2.5,3,3,7
WD 74g raptor 10,000rpm .9at
SONY dvd rw 16x
blablabla
so on and so on