unable to OC an nforce4/opty combo

[skyking]

epox ep9npa3 ultra
opty 144
I purchased a combo(minus ram) from somebody on the net, it was set in the BIOS
at 300fsb.
It refused to boot at that level with my ch5 or any other ram. It would default and boot fine.
I started investigating, and the memory lock function does not work. Whatever I set the cpu at, the memory runs at.
Does anybody have experience with something like that? time for an RMA?

 

[MichaelD]

I've never worked with that combo before, but I'll try to help.

Sounds like someone took an overclocked system that worked for them and sold it to you (minus their memory), and the board doesn't like your memory.

Did they specifically tell you that the CPU was running at 300FSB? It obviously not DOA...but possibly the combo was pushed a bit too far...and gotten rid of? I hope not.

Have you reset the CMOS? Flashed to the latest bios? How is your PSU? Decent?

 

[RichUK]

Originally posted by: skyking
epox ep9npa3 ultra
opty 144
I purchased a combo(minus ram) from somebody on the net, it was set in the BIOS
at 300fsb.
It refused to boot at that level with my ch5 or any other ram. It would default and boot fine.
I started investigating, and the memory lock function does not work. Whatever I set the cpu at, the memory runs at.
Does anybody have experience with something like that? time for an RMA?

Have you tried the memory dividers. VERY few DDR memory modules could reach 300HTT.

Trying looking for the memory divider options within the BIOS. They most likely have the options of 166, 133 etc. For example if you set the 100 divider when running 300HTT you'll memory will be running stock at 200Mhz.

 

[skyking]

OK, back from a furious round of investigation
Ram tested fine at stock speeds and tight timings, with no cpu overclock.

I jump up the cpu, and expect similar ram performance, eh?
I have been mucking with the dividers all along, but it would really fail miserably well below 200fsb on the ram.
I went in and totally relaxed the ram timings, and VIOLA! it will run the ram and boot into windows all the way up to 233 fsb on the ram.
This is not typical in my experience.

 

[RichUK]

Originally posted by: skyking
OK, back from a furious round of investigation
Ram tested fine at stock speeds and tight timings, with no cpu overclock.

I jump up the cpu, and expect similar ram performance, eh?
I have been mucking with the dividers all along, but it would really fail miserably well below 200fsb on the ram.
I went in and totally relaxed the ram timings, and VIOLA! it will run the ram and boot into windows all the way up to 233 fsb on the ram.
This is not typical in my experience.

Yeah I?ve experienced this phenomena too with the many Opteron and Athlon s939?s I?ve owned. I found when the memory controller is stressed with high HTT frequency, the processor suffers with memory performance, whether the memory is capable or not at a given speed and latency timing.

 

[myocardia]

Originally posted by: skyking
OK, back from a furious round of investigation
Ram tested fine at stock speeds and tight timings, with no cpu overclock.

I jump up the cpu, and expect similar ram performance, eh?
I have been mucking with the dividers all along, but it would really fail miserably well below 200fsb on the ram.
I went in and totally relaxed the ram timings, and VIOLA! it will run the ram and boot into windows all the way up to 233 fsb on the ram.
This is not typical in my experience.

Congratulations, you've now figured out how to overclock. Well, sort of. I'd check out this thread, since there seems to be alot of other things you could learn: link.